Advice to President Obama: Grasping the Building Energy Bull by the Horns
Posted by Gail the Actuary on January 30, 2009 - 10:44am
Mr. President, your inaugural address recognized “the ways we use energy strengthen our adversaries and threaten our planet”. You’ve touched on two crucial challenges that America faces; reducing our dependence on energy sources of a foreign or fossil nature, and reducing the damage we cause to our own biosphere through pollution from many of those same power sources. Since the energy crises of the 1970s, we have been slowly sleepwalking back into a culture of excessive overconsumption, backsliding in our addiction to cheap, non-renewable, polluting energy sources.
Figure 1 shows that the largest part of our energy consumption resides in the building sector, making this an area we must place a high priority on improving (and improving drastically). Fortunately, drastic improvements are within our grasp...
Architects know that buildings can be designed to operate with far less energy than today’s average U.S. building at little or no additional cost. -- The American Institute of Architects
The 2007 House Energy bill sought the updating of building codes to reduce primary energy use (i.e., heating, cooling, lighting, and ventilation) of new buildings by at least 30% by 2010, and 50% by 2020. While this provision was struck due to procedural blocks by some Senators, it showed movement in the right direction; however, with many significant advancements in building energy efficiency, the levels should be higher and sooner.
Well-insulated homes that capture the warmth of the sun cost very little extra to build, but provide significant cost savings.
For example, DoE’s NREL monitored one passive solar house built 16 years ago, finding primary energy costs savings of 56% compared to similar houses built to the Model Energy Code; small tweaks in the design could have realized a total of 70% energy savings. It may surprise some, but this house cost no more to build than other homes in the neighborhood. With regard to commercial and government buildings, an initial upfront investment of up to $100,000 to incorporate green building features into a $5 million project would result in a savings of at least $1 million over the life of the building, assumed conservatively to be 20 years.
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| Figure 2 - Comparative Energy Savings of a Passive House | Figure 3 - Bedzed development in UK uses 88% less heating energy |
Stepping up a level, the Passive House architectural movement (originating in Germany) has been realizing designs that save 75-90% of a building’s primary energy use. Architecture 2030, an independent research organization, understands that strides that can be made in building energy efficiency. In 2006, it initiated the 2030 Challenge, which calls for a 50% reduction in new building energy fossil fuel use by 2010, and net-zero energy use by 2030. The UK is much more aggressive with a net-zero requirement for all of its new buildings by 2016.
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| Figure 4 - The UK is already producing net-zero energy buildings | Figure 5 - The net-zero energy Audubon Center in Los Angeles |
Weatherization of older homes helps to improve energy efficiency and reduce energy use.
Existing homes must also be addressed. The current weatherization program creates 52 direct jobs and 23 indirect jobs for each $1 million invested in weatherization work. For every $1 invested by DOE, the program leverages $1.53 in other federal, state, utility, and private resources.
Current energy requirements for replacement HVAC systems are also improving far too slowly. For example, the current minimum energy requirement for heat pumps is SEER 13; my 11 year old heat pump is SEER 16, so clearly we can do much better. And gas furnaces achieving 92% efficiency have been on the market for decades, though the current minimum is only 83%.
So while the challenges are real, the change to sustainable solutions now only requires us to take action.
- Challenge: New buildings continue to be built, even in this economic environment, though they are using model energy codes that are only marginal improvements over the state of current energy efficiency practices. Much larger strides should be made, as evidenced by Architecture 2030 and Passive House.
- Recommendations:
- Forge new model energy codes for residential/commerical/industrial buildings that stipulate primary energy reductions of;
- 50% by 2012,
- 75% by 2016,
- net-zero energy by 2020
- Institute inspection procedures (commissioning with projected energy use) ensuring that new buildings meet these minimum requirements before they can be sold or occupied.
- Tax larger new homes in a manner similar to gas-guzzling cars, and provide tax incentives for compact new residences, similar to the plug-in hybrid electric vehicle credit.
- New residences exceeding 30 million BTUs/year projected primary energy use are taxed incrementally; those less than 5 million BTUs/year receive tax credit
- Have new building developments attain a minimum of LEED for Neighborhood Development (Gold)
- Accelerate appliance energy efficiency improvements, including a near term 'smart' appliance and thermostat standard
- Challenge: Existing buildings, especially older ones, use much more energy per square foot than new buildings. Most have inadequate insulation and draft protection; existing weatherization programs have been shown to produce significant cost savings (which are underestimated).
- Recommendations:
- Accelerate the weatherization program you propose from 1 million homes per year to 3 million homes per year by starting an "Energy Corps".
- Require commercial and industrial building renovations to meet 75% of the new building improvement requirements by the timeframes (see above)
- Require residential building air-to-air heat pump replacements systems to achieve a minimum of;
- HSPF 8.5 and SEER 16 by 2011
- HSPF 9.0 and SEER 18 by 2013
- Require gas furnaces to achieve a minimum of 92% AFUE efficiency by 2011
Americans are eager for change from buildings that needlessly waste energy to those that provide greater energy security and less climate impact. Indeed, some of us are already walking the walk. The practical means and technology to significantly lower the energy requirements of our building sector is in our hands. As you said, "Our scientists, businesses and workers have the capacity to move us forward." All that is required for widescale energy and emissions reduction is for leadership to seize the moment.
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Thanks again Will for sharing your expertise in this area with our readers.
I was surprised to see that 48% of our energy consumption is in buildings - that fact alone suggests we can reduce consumption pretty sharply if necessary. Two related questions:
1)how much of that 48% is 'already built'? (e.g. how does the 48% breakdown into fixed vs marginal)
2)Is there a reason that big cities keep their skyscraper lights on most of the night? How much energy does this use - is the only reason for the janitors to be able to clean/see? If so it would seem enormous energy saving could come from an 8pm-4am lights out curfew. (of course, the natural course of things this WILL happen, but not in planning only when the power shortages arrive...)
I would interpret the 48% to be what is used in a given year by people in buildings of any sort, other than that which is considered industrial use. I am not certain to what extent the building of buildings actually gets into that number.
Thus, it would include computer usage, lighting, elevators, and air conditioning in office buildings. It would include cooking in restaurants, and all of the medical equipment in hospitals. In homes, it would include heating, air conditioning, cooking, computer and TV usages, hot water heating, clothes dryers and a lot more.
Will, do you have any breakdown of this?
It will vary widely based on;
- Location (heating and/or cooling in Anchorage vs. Miami, for example)
- Type (residential, government, commercial, industrial, municipal)
- Sub-type (hospital vs. town hall, steel foundry vs. cell phone manufacturer, etc)
Some examples include;
Nate asked:
"how much of that 48% is 'already built'?"
That represents the current mix of energy use among sectors, so that would be 'already built'. If all sectors drastically reduce energy by the same percentage (unlikely), that mix would stay the same.
Yes, it is very important for people to realize how much energy our buildings use.
The problem is that not much new building is going up, and it takes much more skill and cash to retrofit than to do it right the first time. This article talks about $100,000 for superinsulating a home, and I've heard similar figures from specialists in the field. Insulating all the houses that need it would be a major expense, but then we are after all in the days of near-trillion-dollar bailouts spent on much stupider things (as we now see, to pad the year-end bonuses of the very bankers that drove the nation's and the world's economy off a cliff, for example).
http://news.bostonherald.com/business/real_estate/view/2009_01_17_Mass__...
Superinsulating would greatly reduce the peak load in the hottest days of the summer, generally the times of the highest use of electricity. Since el. generating capacity has to be built to handle such peaks, lowering how much is needed at these times is a big part of what we need to do. (For this same reason, PV is an important part of the equation, even though it's EROEI is not as good as large-scale wind)
In the winter, of course, superinsulation could hugely reduce dependence on natural gas, heating oil, and inefficient use of el. for heat. For those of us in the far north, it could be a matter of life and death, as shortages in heating fuels start cropping up.
In addition to super insulation, roof fans to reduce attic temperatures (which can reach 120 degrees F or more on a summer day) by bringing in relatively cooler air can drop 15 to 20 percent of electricity used for AC. From personal experiece, it is nice to have these on a switch or reasonalby accessible breaker, as the bug population gets out of hand unless they are periodically "roasted".
Agreed, there are many techniques available such as this to reduce energy consumption. Such vents can be solarPV-powered, solar chimney-powered, 'breeze'-powered, etc.
AC is a luxury that should be banned outright - maybe except in all-glass office buildings.
AC is a luxury that should be banned outright - maybe except in all-glass office buildings.
You obviously don't live in a desert climate.
While there are building techniques that can achieve some measure of passive climate control in true deserts (much of Southwestern US, Mexico), no passive system can adequately cope with 100F+ heat. Then there's the problem of cooling inefficient pre-existing housing stock. Even if the law mandates strawbale, cobb & earthship construction going forward, can we replace tens of $Trillions worth of perfectly good structures overnight (and tear-down historic buildings as well)? I don't think so.
Do we dare to question how smart it is/was to locate gigantic cities and sprawling suburbs containing millions of people in them in the middle of deserts? Especially when people living there can't conceive of doing so without deeply cooled artificial environments and pools in every yard?
People lived in the deserts long, long before AC, just not in huge numbers.
Perhaps its time to get out of the kitchen if you can't take the heat. And the heat is going to be increasing considerably.
"can we replace tens of $Trillions worth of perfectly good structures overnight (and tear-down historic buildings as well)? I don't think so."
Agreed. That's why I mentioned retrofits. But even that is going to be a hefty bill.
There are cheaper ways to do it--spray on insulation--but it leaves a surface that people describe as like "living inside a tennis ball"--not everybody's cup o' tea. But then perhaps a tennis ball is better than an oven, a freezer, or ... a coffin?
Dohboi: living inside of a tennis ball? Never heard that one. I live in an extremely cold place and insulated my last addition with spray foam between the joists and rafters. The results were astounding. I would never insulate any other way again. R35-40 walls and floors and R60+ roofs are really amazing and comfortable and utterly silent. An unexpected bonus is that spray foam between two sheets of cladding makes for an extremely rigid massively strong panel structure.
As I recall, the comment was about a spray on insulation that becomes itself the new inner wall surface of the building. I think the "tennis ball" part was partly inspired because it was a small geodesic structure. I'll see if I can track down the source. Thanks for all the comments, everyone.
Might want to keep an eye on those timbers that have foam sprayed on them: my engineer tells me it causes them to rot. One house he inspected at rotted every timber with foam on it by the time it was 5 years old! And that was in Fairbanks AK, which is a very dry environment (and cold! -18 here right now...going to be very hard to get those 'net zero' buildings here). I suppose you could keep the moisture out with proper vapor barrier, but it is still taking a chance. Of course there is a place here that is made of *all* foam (between Fairbanks and Anchorage), but that turned out to be a big mistake because they could never use it due to the outgassing of formaldahyde--even after 20 years it is still a problem.
Here in N. Nevada, we have record low humidities. Last year I think it was measured at 4%.
In these dry areas AC is pretty much extravagant, because the lowly evaporative cooler (swamp cooler) works so well.
Ours will drop the temperature as much as 25 degrees below ambient (that's with wood-straw pads, not artificial which work less well.)
I'm guessing the swamp cooler uses 1/3 the energy of AC, but am not sure.
The disadvantages are they do use water, need new pads every so often, and must be drained in winter.
During summer, it turns on very early in the morning via a simple timer, and keeps the house quite cool until mid-afternoon.
On really hot nasty days we do supplement it with small window AC units, and also use them when the humidity rises too much.
An of course we open windows in the cooler evenings to get that cold night air into the house.
We've made thermal curtains for our windows, and use these summer and mostly winter.
We really should make some shutters for our West facing windows, as it seems that is the most heat-introducing area.
Outside shutters keep the heat from getting into the glass.
My kid had a large sliding patio door facing west with no trees or shade in his little condo. I calculated that his heat gain in the afternoon was about the same as having a 1500 W electric heater on in the house. We put up a bamboo type shade on the outside of his window and it greatly helped.
A friend has a stall in a large windowed building and sells antiques. He says the AC goes all day during summer, and suggested to the managers that they install a ceiling exhaust fan(s) to get rid of that tremendous heat at night, and get that cool air inside.
They don't want to spend the money to put in such a system, but instead are willing to pay those huge summer power bills.
Being handy, he offered to put a system in, but still they don't want to outlay the money....
Now perhaps he should approach them again and say, "listen, I'll put the system in, and pay for it upfront, if you will give me half of the savings over the next (undetermined) amount of time." He could probably make a handy profit, and help our collective energy use.
IMHO, the solutions are building underground and bermed, planting deciduous on south walls, painting roofs white, and using nighttime cooling.
And of course liberal use of swamp coolers if your area is suited for it.
Swamp cooler are a great assist to existing AC systems.
They'll allow using AC as an assist, instead of vice-versa.
Great replys here, thanks, I learned a bunch.
A BTU saved is a BTU earned.
These are the sort of projects that should have the stimulus money thrown at them. Imagine a large south facing window being fitted with a horizontal sun shade with a few hundred Watts of PV mounted on top being used to power a ceiling fan indoors.
Using composting or other forms of dry toilets can save enough water to use swamp coolers, and the night time breeze can be used to make ice for cooling during peak times.
In the eastern USA high ozone on hot summer days can be deadly to asthmatics like me. I had a very close near death experience on one of those days back in the 1990s. Just a few years ago thousands of vulnerable people died in France do to lack of A/C. It could be reasonably estimated that 100 times as many were sickened enough to be life threatening.
Houses in climates that need A/C generally use less energy overall than houses in colder climates. So I guess you would have us ban heating as well. What about banning refrigerators while you're at it. They consume as much energy as A/C.
I am new to posting comments but have greatly enjoyed reading the Oil Drum for quite some time. I live in Tucson and often hear the comment that large cities should not be built in hot deserts. But as Paul alludes to, from a heating/cooling perspective it is not clear why it would be better to build a large city in Minneapolis, Chicago or Edmonton. I'd be interested in links to studies that quantitatively analyze the average total energy of heating/cooling as a function of latitude. But in any case, perhaps the more pertinent issue with Tucson, Phoenix and Las Vegas is how we use our limited water resources.
I forgot where I saw the actual numbers on this. I remember I found them by searching such things as "energy consumption typical house" and looking at utility websites.
For design purposes see "Cooling Degree Days" and "Heating Degree Days" as "maps".
http://lwf.ncdc.noaa.gov/oa/documentlibrary/hcs/hcs.html#51overview
NOAA keeps changing their website, but you can find this somewhere on the National Climate Date Center NCDC website.
Water indeed is a major limiting factor in the West and Southwest generally. (Though I'm glad to hear that CA has recently got some relief from their drought. No. China, on the other hand, seems to be in fairly dire straits.)
And water will become ever more scarce as GW really kicks in. And remember that in an oil depleted world, if you can't grow crops in your region from rainfall, it will become more and more difficult to truck all the food you need in from wetter regions.
You can get into a really warm sleeping bag and otherwise dress for the cold. But to escape the heat, there are only so many layers you can take off before you can't go any further ;-}
But of course, just as super insulation and geothermal can help in the north, similar techniques can protect from the heat. But most structures built in the last fifty years in the south were built on the assumption that AC would be forever available.
Correction. Refrigerators do not consume as much electricity as A/C.
Don't forget the Cool Roofs concept. Paint those shingles white and less energy for cooling will be needed. Do the same with pavement and you go a long way toward eliminating the heat island effect. Do it on a large enough scale and you can increase the Earth's albedo and slow climate change. A big bang for the buck.
Metal cool roofs work extremely well. Asphalt shingles absorb more heat because of the coarse texture.
If this is redundant: Thomas beeat me to it...
Besides superinsulation and attic ventilation. Change the building code to encourage/require heat reflecting roofs.
This might be in conjunction with code and insurance changes to encourage metal roofs. Composite shingles last 20-25 years and are unlikely to be recycled, if they are recycled. Metal can be painted light shades and is hail resistant, dents don't count, and metal should last 50-100 years.
I have noticed flying into DFW airport, almost all industrial buildings around the airport have light colored roofs. The residential housing in the area is all dark to black. This in a geographical area where cooling is the largest energy user. The solar heating benefit of dark roofs is minimal in winter judging by my house in Tulsa, OK.
Encouraging insurance companies to come on board is because wooden shakes and composite houses suffer more damage from weather and fire than metal roofs in my observations in the local area.
I just put new metal shingles on my 70 year old farm house this last year and I get a very sizable discount on my homeowners insurance as a result of putting on insurance company approved metal shingles.
So the insurance companies are on board (At least State Farm is).
"(At least State Farm is)"
Not if you're in Florida--they just pulled out of that market.
Metal roofing is widely used along the Gulf Coast. It has much better hurricane resistance than asphalt.
My homeowners association refused to allow me to use the most energy efficient color; however I was able to get a gray with 38% reflectance, which qualified for a $500 tax credit.
I have been told that sealing out air leaks is important. This is a change that can be made relatively inexpensively and can have a quick payback.
But if you do this too successfully and don't have an air-to-air heat exchanger, your indoor air can become quickly nasty, even toxic.
I think retrofitting (making energy efficient) old houses may be difficult, and this may be a problem. What is needed and what can be done varies by region.
Sealing leaks is described by some around here in NH as the FIRST thing to do, even before insulating. It is more than just "leaks"... vertical passages in a house, from basement to attic, exist e.g. the plumbing vent pipe, electrical wiring, chimney "chases", hot-air-duct passages and the like. These passages set up an air flow called the "stack effect" or "chimney effect", with momentum and with cold air coming in downstairs to replace air we've paid to heat that is exiting upstairs. Taunton Publishing has a good book "Insulate and Weatherize" (or vice-versa!). In my old house we had all of these, plus the natural gas water heater vented freely into a chimney, sucking additional air out of the basement even when the gas was not "on". We also had a lovely old coal fireplace which we sealed by holding a dry-cleaner bag over the iron cover, allowing the air pressure in the room to press it against the cover and hold it in place, 24 x 7, just based on the chimney effect.
You have to seal a house darn good to worry about toxins. An old house, you'll probably never be successful to the point of suffocating... :-)
We built a new house that is seriously tight, and we're tightening it more. We have an air exchange system with a heat exchanger that salvages some heat and humidity while swapping bad air for new air. When it's 60 degrees inside and 20 below outside, we are so lucky we get fresh air that's between 10 and 20 above... When the sun is out, we ignore the wood stove (Jotul #3) which is our sole source of heat. Front (south) windows have a glass invented by Livermore Labs I think and probably used in Canada (and which is far better than the standard "low E" which is designed for the south and southwest and blocks 50% of incoming solar energy) and has a film of silver that reflects "far infrared" back into the house while allowing nearly 100% solar energy in. The house is about 1800' plus full basement.
If we need more room we can add a wing that is cheaper to build and not as warm - the house as it is now is a suitable "core" for winter. One idea for old houses is to identify a core within the larger house and set up a thermal boundary around that core. Give up on fixing the whole thing... I am interested in this problem and the more I learn the more difficult it all seems.
Usually, older homes are so drafty that sealing many of the main leaks might bring them to 1 air change per hour (ACH). Newer tight construction, or a really good renovation might require a heat recovery ventilator.
Remember, that for most of the year the lights are supplying beneficial heat to the building. If you turn out the lights, you will have to run the heating system more to make up the lost heat from the lights.
Would you rather have that heat come from electricity or from natural gas/ oil furnace?
Some times things are not as clear cut as they seem.
I think that's a really good point that probably about 0.5% of the population understands. Really burning natural gas for heat is wasteful since we could use that gas to do something useful before all of the energy is essentially lost. Same goes for electricity. Of course the whole thing runs backwards if you're using air conditioning.
Lighting supplies heat but not exactly useful heat as most of it is supplied at ceiling level, which is not a very useful part of the house to heat.
For those of us who heat with heat pumps, the waste heat given off by lighting displaces/offsets a portion of the heat that would be otherwise supplied by our heat pumps at one-half to one-third the cost. The net result is that this waste heat increases our heating costs because it reduces the demand for this lower cost alternative.
Cheers,
Paul
Many areas of the country are really not suitable for air to air heat pumps. that is a dream. At -30F or -40F, they do next to nothing.
The SEER going from 13 to 16 accomplishes little, other than enrich a lot of manufacturers. The problem is cycle time, and the efficiency at which they operate. A SEER of 30% higher value won't save you 30%. Maybe 5% in electric bill.
The folks here tell you you are wasting your money to put in anything over the absolute lowest required standard at the current time. You'll never get payback, and the added expense/complexity means higher maintenence costs and life cycle costs.
The efficiency of the higher SEER only kicks in after 5 or 8 minutes of operation...and most A/C units are off at that point.
Many areas of the country are really not suitable for air to air heat pumps. that is a dream. At -30F or -40F, they do next to nothing.
Agreed, for those areas. However, I was referring to replacement air-to-air heat pumps, so if there wasn't one there already, there won't be one after (unless a conversion to a ground source heat pump occurs).
The SEER going from 13 to 16 accomplishes little, other than enrich a lot of manufacturers. The problem is cycle time, and the efficiency at which they operate. A SEER of 30% higher value won't save you 30%. Maybe 5% in electric bill.
My understanding is the difference between SEER 13 and SEER 16 is roughly 20% (equal to 1 - 13/16). 20% is a significant savings, especially when also combined with any other improvements.
The folks here tell you you are wasting your money to put in anything over the absolute lowest required standard at the current time. You'll never get payback, and the added expense/complexity means higher maintenence costs and life cycle costs.
There are certainly any number of opinions on this matter. This particular topic is about saving energy, though lifecycle costs are a consideration. Any empirical data you can present to support your position (including external costs) is welcomed.
The efficiency of the higher SEER only kicks in after 5 or 8 minutes of operation...and most A/C units are off at that point.
I wouldn't make such a sweeping statement myself, except for oversized systems, perhaps. Two-stage, variable air volume systems will operate at the optimal level and cycle rate, not a quick on-off cycle. Such systems are more effectively able to work with multi-zones, providing greater efficiency through the heating/cooling of spaces on a temporal basis (e.g., heat/cool upstairs only at night, etc) and are also more conducive to context aware techniques.
The efficiency of the higher SEER only kicks in after 5 or 8 minutes of operation...and most A/C units are off at that point.
A properly sized A/C system should have a long cycle time or else it does a poor job of humidity removal plus operating inefficiently.
Not enough HVAC contractors are using Manual J for load sizing. Also, there is a tendency to add a safety factor. A properly sized A/C system should have a long cycle time or else it does a poor job of humidity removal plus operating inefficiently.
Contractors who tell you not to pay for the more efficient equipment are partially right. The payback time can be long. However, they often do not want to take time to source the better equipment and learn how to install and maintain it. Some of them will order large quantities of standard efficiency units in various sizes off season at low prices and only install these systems. They can do it very economically, making it hard to justify higher efficiency equipment.
If you look hard enough you might be able to find a contractor who specializes in high efficiency systems who can give you a better price.
Some of them will order large quantities of standard efficiency units in various sizes off season at low prices and only install these systems.
And of course, if the standard becomes SEER 16 and then SEER 18, this trend can continue with the new standard.
I respectfully disagree. That may be true if you expect a heat pump to provide 100 per cent of your total space heating needs. What about 90 per cent? Or even 80 per cent? Could a heat pump still be cost effective for those of us who heat with oil, electricity or propane? There's absolutely no doubt in my mind that they can.
If I spend roughly $800.00 a year to cool my home, a 20 per cent reduction in cooling costs represents a savings of $160.00/year. If the added cost of upgrading to 16 SEER model is $1,000.00, I earn a 16 per cent non-taxable return on my investment and presumably the numbers will only get better with time as electricity rates continue to escalate higher.
People say all sorts of things, like you shouldn't turn fluorescent lights on and off because it they'll use more power and that you shouldn't turn your heat down at night because your furnace has to work harder to bring the house back up to temperature the next morning. Folks may genuinely believe what they say is true or they may be simply parroting what someone else told them, but that doesn't mean it's true.
If your CAC cycles off after five minutes, then, quite clearly, its grossly oversized. My inverter drive heat pump (18 SEER/9.3 HSPF) runs continuously as it constantly adjusts itself to changes in load; there are, in effect, no standby losses.
Cheers,
Paul
I have wondered about how effective heat pumps would be up where it is very cold for a long time. Here are the heating degree days (at our airport) for this season. Are they enough info to give some indication of what a heat pump can do in this area?
The first number is this year and the second are normal (average) year numbers. This is Fahrenheit land.
DEGREE DAYS
HEATING
YESTERDAY 80, 74
MONTH TO DATE 2215, 2167
SINCE DEC 1 4463, 4366
SINCE JUL 1 8994, 8554
Hi Luke,
Our city has 7,900 HDD, which makes us about 20 per cent colder than Buffalo, NY and just slightly colder than Minneapolis, MN, at 6,600 and 7,460 HDD respectively. I think it’s fair to say we're pushing the envelope in terms of how well we might reasonably expect an air source heat pump to perform given the nature of our climate. One thing to note: compared to the mid-west, we don't get a lot of bitterly cold weather; our coldest temperature so far this winter is -23C/-9F. I recall in January, '04, we dipped to -27C/-17F, but that's somewhat unusual for those of us here on the coast. On average, there are just sixteen hours in any given year when temperatures in Halifax fall below -20C/-4F, the point at which most air source heat pumps basically call it a day – that translates to be an availability factor of 99.997% based on our standard heating season.
In any event, Halifax falls within Zone 4 and our small Sanyo ductless heat pump has a Zone 4 HSPF rating of 9.3, which converts to a seasonal average COP of 2.74. That means that for every kWh of energy consumed, it provides an average of 2.74 kWh of heat in return. I currently pay $0.11796 per kWh, so if I divide this number by 2.74, my average cost per kWh of heat is effectively $0.0431.
My oil fired boiler has an AFUE rating of 82%, so I net 8.77 kWh of heat from each litre of oil. My tank was last filled October 24th at which time I paid $0.969 per litre, so my cost per kWh of oil heat is $0.1105. If my tank were filled today, I would expect to pay something in the range of $0.739 a litre, so my cost per kWh of oil heat would be $0.0843. Even at today's reduced prices, the operating costs of this heat pump are half that of oil and a little more than one-third that of electric resistance heat.
I should also note that this particular model maintains over half its nominal heating capacity at -18C/0F, which is something I find quite remarkable. I estimate our home’s heat loss at roughly 0.170 kW per degree C when outdoor temperatures fall below 13C/55F (at temperatures above 13C, passive solar gains and the waste heat generated by lighting and appliances are generally sufficient to maintain normal room temperature). Based on data provided by Sanyo, a single ductless unit should be theoretically capable of keeping our 2,500 sq. ft. home at a constant temperature down to -6C without any additional assistance, and two ductless units should cover us off down to -15C.
The installed cost of this Sanyo was $US 1,700.00. My other ductless heat pump is an older Friedrich model with a HSPF of 7.2. I hope to replace it with a second Sanyo sometime later this year and, with that, eliminate just about all of the oil we currently use for space heating purposes – some 250 litres or 66 U.S. gallons in all.
Cheers,
Paul
Thanks Paul, 50% of nominal heating capacity at zero F does seem worth investigating. I live about 1000 ft above our airport, that gets us above the cold inversions and generally we do not see extended temps below minus 20F but we do get months of 0 plus or minus ten degrees F. I guess where the temp sits in that plus or minus range makes or breaks the heat pump. You probably noticed that since July 1, we have already had 1000 HDD more than Halifax averages yearly. Annually Fairbanks (airport) averages a whopping 13976 HDD.
The Monitor kerosene heater we burn #1 diesel in operates in the 90% efficiency range, but the house has outgrown it a little (the second floor bedrooms know the heater is in the basement when it is -10F and lower) Last summer I paid over $4/gal., this month it was $2.20. We paid .016/kWh last month but the fuel surcharge was less than half the .08/kWh it was last year. Our place is about 2100 sq ft and we burn better than eleven times the oil you do. A couple of heat pumps may have $ room enough to help us out, it would seem they could handle the four milder months of winter even if they were mostly idle for the other three deeper winter months. It is certainly worth my doing some homework.
I have been dragging my feet on getting my hot water heat system in (as I get the levels finished I install the baseboard and zone runs) maybe I will be glad I haven't yet installed a boiler. I guess I should first see if there are heat pumps that work with a hot water heat system (that already has an expensive sound to it). Since this is a five addition (much more intergrated than that sounds) out of pocket 15 year project, some areas are built a little more effeciently than others. Out of pocket and short seasons can help that happen.
Which brings me back to Gail's most excellent post. Hey Barack we could use a little help here.
Thanks again,
Bob
Hi Bob,
Thanks for the additional information. Fairbanks, AK is one tough nut to crack. The economic advantage of an air source heat pump at 14,000 HDD would be largely restricted to the swing seasons and, in your case, late spring and early fall. I took a quick glance at the weather almanac for Fairbanks and I'm not overly optimistic. If your home were electrically heated, it might work given the relatively high cost of electricity but, as it stands now, it makes more sense to stick with oil.
FWIW, I have a limited amount of in-floor electric radiant heat that I use for spot heating (see: http://www.suntouch.com/sunMatIntro.html). If your bathroom has a tile floor, a small 2 x 5 ft. mat such as this uses just 120-watts, and if you connect it to a programmable thermostat, you can have it set to come on a couple hours before you get up and then turn off as everyone heads out the door. Assuming it operates four hours a day, your useage is less than 15 kWh per month, which is not unreasonable figure given the added comfort they provide.
Cheers,
Paul
Hi Paul,
Thanks for the extra look. I was kind of thinking that we might be in the marginal area for heat pumps. The University of Alaska Fairbanks (UAF) has a couple year old Cold Climate Housing Research Center (CCHRC} which has been building up some real world data on boiler systems, insulation configuration, PV arrays and more, but as it often the case up here the capital project funds to start the center were the easy thing to get. A fully functioning operations budget can be harder to come by, and then the typical feudal turf organization of grant seeking university departments doesn't help allocate expended human and capital energy any to efficiently either . But all must do the best we can with what we got.
Mahalo,
Bob
I too live in Fairbanks, and some years ago I looked into heat pumps that use ground temperature. I discovered that several people had attempted them. The story I got was they just caused permafrost--they took too much heat out of the ground and it wasn't able to recover over the summer. I'd like to see what one could do with them using 32 F water; those living on the river might be able to utilize river water. (This wouldn't work for me; I live in the hills up off the Steese.)
Hi Ray,
I've been corresponding with a professor of architecture at the University of Waterloo who has evaluated the real-world performance of numerous ground source heat pump installations throughout Canada and in his opinion, GSHPs work best in "climates with moderate ground temperatures, and [buildings] with approximately equal annual heating and cooling loads". From what I'm told, if heating loads significantly exceed cooling demands, there is a strong possibility that ground temperatures will fall over time and the risk of ground freeze, especially towards the latter part of the heating season, increases considerably.
Cheers,
Paul
One solution to that is to add heat gain; for instance, a solar water heater with a "heat dump" to the GSHP ground loop. This heats most of your DHW in summer and keeps the ground from freezing.
Wouldn't it take a heck of solar dump to heat the ground enough in three or four months to handle eight months heavy heat pump heating. Our winter sun is an extremely low angle so it would help very little for the dead of winter months. In my case a rather low rise to my south blocks the direct sun from my house for a solid 80 days bracketing solstice. It would seem you would have to excavate and insulate a large volume to get enough ground warm enough to handle our 14,000 Heating Degree Day load.
If all you need to do is keep the ground above freezing, just collecting heat from the air during the warmer months would do. Another partial solution might be to route the roof runoff through pipes which percolate through the zone used for heating. Inordinately cold water would be replaced every summer by warmer water, eliminating the permafrost issue.
Hi Paul,
From what I've heard I'd say that is likely, and with our ground temperatures of just slightly above freezing it really doesn't work. (Note that here in Fairbanks our cooling load is tiny. Indeed, properly handled there isn't any--I keep my house cool simply by reducing the heat load as far as possible [eg turn off the boiler, so no domestic hot water] during the hottest days, and using these techniques can keep the house under 75 even on the hottest days. Which seldom--once a decade-- reach 95.)
Of course, as the following person notes, you can always add heat into the ground during warm months. But I'm not sure this added layer of cost would keep it feasible financially...
Cheers,
Ray
Hi Ray,
We seem to be neighbors. Openning windows (after the peak daily high temp) a metal roof and use of fans seems to deal with my entire cooling load on our few hot days. Last summer I wondered why I had put some many operators in my W & SW final addition. I rarely openned them half way. The Canadian triple glazed windows have moderated my in house temps considerably over what I had before even with my oversized glass area--I am willing to pay for getting lots of natural light inside through our extended cold season, it heals my soul. Next up finding good night shades that don't ice up the windows when closed. Any suggestions?
I went down to CCHRC to see what sort of info they had on their side by side, by side, by side boilers, specifically to find whether the efficiency of the Monitor badged hot water radiant floor system was +/-/= to the baseboard systems they were running but it ended up their design didn't provide that sort of data. I'm certain floor plan and other consideration come into play anyway. Pretty much the research center people had managed to verify the boiler manufactures efficiency claims. That didn't help me to much in going forward with my project decisions.
Bob
Hi Ray and Bob,
Obviously, something like this is only suitable for larger scale requirements, but for a small town with abandoned mines it's a terrific option (we have a similar system operating in Spring Hill, Nova Scotia).
See: http://srj.ca/default.asp?sourceid=&smenu=88&twindow=Default&mad=No&sdet...
For additional background on mine water systems, see:
http://docserver.ingentaconnect.com/deliver/connect/epp/09670513/v11n2/s...
Cheers,
Paul
there is hope for the north
Excellent Will.
I've felt for some time that energy conservation is the second most important step that could be taken in 'solving' our energy problems. Second because I maintain that stopping the manufacture of trivial and excessive 'entertainment' products and reducing the discretionary services (or at least taxing them) could be done immediately and have an impact immediately, if not energetically at least psychologically. It would, if nothing else, underscore the seriousness of the problems and be a tangible demonstration of what 'sacrifice' will mean in the long haul. The problem, of course, is that so many people's incomes are based on jobs in these businesses. On the other hand, maybe jobs in your 'Energy Corp' might be good substitutes.
Ramping up a manageable conservation implementation effort (e.g. 1 million homes to 3 million, as you suggest) will be tricky with lots of up-front costs, but doable I think.
Now if you can sell these ideas on the basis that it will be a more effective part of a stimulus package, the politicos might go for it. They are looking for ways to get the economy going again (meaning the way things were in the good old days). They still don't grasp that we need to use this downturn to build a new kind of economy based on sustainability rather than growth. We have an opportunity to get things right, but will more likely screw up what could be our last chance. (Boy did I wake up on the wrong side of the bed this morning!)
Anyway, great work. Keep it up.
+1
I agree, thanks Will!
Anytime. Anything I can do to help us mitigate the energy cliff is my main objective.
One thing that needs to be done very badly is to change the property tax codes to eliminate the terrible tax penalty for Investing in Insulation. If you spend $50,000 to Super Insulate your home many government entities will say that is an "Improvement" to your home and raise your property taxes dramatically. If you invest some of your retirement funds in Insulation instead of stocks or CDs you can get a much better return on investment. But if you have spent the funds on Insulation you no longer have them to bring in the income to pay the increased taxes.
Super insulating a home should be seen as an investment! You do not look to see what the payback time is for a CD or for stocks and you should not for Super Insulation. Can you imagine how many CDs or stocks would be sold if the owner had to pay a hefty 10-30% tax every year on the purchase price of the investment for as many years as you owned it. That is what the property tax on the investment in Super Insulation is.
My current calculations project a 16% return on investment per year (savings on heating costs- currently at the unaffordable point) from Super Insulating my 70 year old (currently) uninsulated farm house. If propane prices go up (If?) over the next 10 years my return on my investment will increase greatly. Propane prices here in Minnesota have gone up almost 4 times what they were 5 or 6 years ago ($0.58 per gallon to $2.32 per gallon this winter)
You don't get your investment back on stocks or CDs until you sell them - And there is no guarantee that you will get your money all back - And that is the same with Super Insulating a home. You won't get your Investment back until you sell the house and there is no guarantee that you will ever get all of your investment back depending on the level of property values when you sell the home.
Super Insulating an older home is probably only really viable for someone that plans to live in the house for at least 10 years. It's a long term Investment!
This may be off topic but I see property taxes as an archaic left over from the 18th century and has no place in the 21st century. Back when most property was farmland and produced an income it made sense. Now there may be little connection to ability to pay especially among retired folks. It has been pointed out many times that property taxes are an impediment to RR electrification. Of course other taxes would need to rise to compensate.
"Of course other taxes would need to rise to compensate."
And then again maybe government could just down size like everyone else is having to do instead of trying to collect too much in taxes.
The government that governs best is the government that governs least!
Wellll, maybe. But as the posts immediately below point out (and as the last year has amply illustrated) sometimes government regulation is the only way to overcome inertia or outright corruption in the private sector.
*sometimes government regulation is the only way to overcome inertia or outright corruption in the private sector.
What will we do if we have corruption in government? Like bribing the inspector.
Rod in Illinois
The people need big government and strong labor unions in order to offset the power of big business. We are in this economic mess because government failed to regulate the big business of hedge funds and derivatives. Big business enables even bigger crooks to cheat us if not outright kill us due to dangerous products and unsafe working conditions. Consider the current peanut scandal. When one inspector discovered salmonella in their product instead of recalling possibly contaminated food and cleaning up their factory they instead went to other testing companies until one of them gave them the result they wanted. Smaller government could only happen if big business went away.
+1
In my opinion, one of the biggest hurdles we face is the social inertia in the construction business. A friend of mine built a house in the NE US just a couple of years ago, via a major home builder, and not only didn't the company offer options for beefed up attic insulation, an attic fan, etc., but when my friend asked about those things specifically he was told that the company didn't offer them(!).
This is why we need to take the next step and pass laws that require these features in new construction, or at a bare minimum make them available. I know this will result in endless complaints from those in the construction business about government butting into their business, but when they do things like my friend experienced, I have zero sympathy for them.
one of the biggest hurdles we face is the social inertia in the construction business
Absolutely. Education and first use of a new technique/component will help 'turn that ship'. Another big hurdle is the availability and quantity of materials/products that are needed to reach energy efficiency goals. Having a policy in place will drive market strategy in these areas to meet the projected demand.
We need to revise the U.S. building codes to dramatically increase energy efficiency and reduce the maintenance cost of housing, such as by replacing wood frame construction with concrete.
Unfortunately, the home buying public will resist anything that increases initial cost, regardless of energy, maintenance and insurance savings. They are also unwilling to trade smaller size for superior quality.
Then there is the resistance from the building industry, who does not want to learn how to do something different, and the timber industry who obviously want to sell lumber.
By the way, I designed and built my own home because I was unable to find a contractor willing to do it, at least for a reasonable cost.
I agree that we need education and persuasion.
We also need legislation.
I've talked to builders in Minneapolis. Minnesota who scoff at the idea of insulation. Last year a builder of big McMansions in Rochester, MN told me that additional insulation and energy saving strategies were not cost effective, and implied that they would never be cost effective in the foreseeable future.
I spoke with a commercial building contractor in Omaha, Nebraska who discouraged a client from building to LEED spec because it simply "Did not pencil out!" and he could not foresee that it would be worthwhile in the future.
We are mostly trained to be illiterate and ignorant except for the specific "job" we have -- as most narrowly defined.
Also, I notice many self-described "Conservatives" and "Libertarians" have deeply ingrained feelings against real conservation. Conservative, free market values have come to describe overt grasping, selfish behaviours: rape is the core cultural paradigm, whether we want to admit it or not. We glorify killing and stealing from others in order to feed our own insatiable wants and desires. Our own wants and desires -- we are taught very clearly in our culture -- have "no boundaries."
There you go, folks. I've encountered far more people in the building trades and far more people seeking to remodel homes in my area who want things done "cheap, quick and dirty" so that they can make short-term gains, without regard for long term considerations.
We need education, yes. But we also need leadership to set the example. This means real laws with real consequences for irresponsible or rapacious behaviour. Wealthy people should be taxed severely if they do not build or remodel to the highest standards. The poor and middle class need to be given grants to remodel for energy efficiency, and need to be given good-paying jobs doing this sort of work.
We need the POTUS, Vice-POTUS, Cabinet, and all business and political and cultural leaders to get the urgency of this into their heads, and then to bring all of the resources they have to bear on this issue, as well as related issues -- transportation, finances.
Much of this has to do with building a moral and ethical foundation.
You say
I can see taxing new larger new homes similar to gas-guzzling cars, but I am less clear on tax incentives for compact new residences. It seems like the tax should go away for compact new homes, rather than become negative. I have two reasons for saying this:
1. Our governments are in dreadful condition. They need additional sources of tax dollars. I think rebate programs are basically likely to go away.
2. Here in Atlanta, and in much of the rest of the country, both residential and commercial is badly overbuilt. Adding a new compact small house adds to the overall housing base, and is thus one more house with appliances (although the additional heating/cooling load is less than it would otherwise be--I wish we could get people to take an old house down when a new one is built). If it is further out in the suburbs (where many new houses are located) it adds to driving distance. We really don't need to encourage people to be building more unneeded homes, even if they are compact. A lack of tax for compact homes should be incentive enough.
The main reason I can see for a rebate is that it would make legislation easier to pass. That way legislators can say that they aren't really raising taxes. How about a tax incentive for taking down drafty, uninsulated old homes?
"How about a tax incentive for taking down drafty, uninsulated old homes?"
It is much cheaper and better for the environment to Super Insulate existing houses than to tear them down and build a new (poorly?) insulated new house.
I think there is just a tremendous opportunity to develop cottage industries (so to speak) based on various retrofits to make old buildings 'code up' to new performance standards.
I wouldn't trade the heavy old beams in this building for any of that fast-growth fir that so many homes today are built from. The framing of this house (1850ish) should be able to stand for another century easily, if it's taken care of. I've got some thermal bridges to burn.. but this whole neighborhood could take the same treatment I'm ~slowly~ giving this house, and it would be just fine!
I do know there are houses so poorly built that they should be redone from the ground up.. but here in Maine, a lot of our old housing has some good stock inside it, so ripping it all out would be a real crime.
Bob
I agree that in general fixing up and super-insulating is the way to go. If a larger number of people can occupy a given house, that is to the good also.
It still seems to me that we are likely end up with a large number of unnecessary homes and commercial buildings. I am not sure what we do with them all, other than leave them for harvesting of reusable parts later.
In most parts of Northern continental Europe, the standard US home would not qualify for a permit. The overall thermal conductivity is
about one third of the corresponding figure of an average US home.
However, there are methods of insulating that reduce heating energy by 10% and pay off in 2 years , by 20% and pay off in 4 years , by 30% and pay off in 8 years , and so on.
If you have to hire a roofer and he is renewing more than 50% of the roof area, he must also improve the thermal insulation according to
the respective valid standard.
These methods could be introduced in US as well, step by step, not super insulating at once.
Odd as this house reharvesting may seem, it has much history when conditions have warranted.
Locally, Fairbanks was the successful gold boom town in the early 1900s but Chena, located at the junction the navigable river and the small one Fairbanks straddles, made a bid to be the permanent town and had a construction bubble of spec houses, shops and warehouses to push that bid along. Narrow gauge railroad and other considerations left the spec town of Chena a ghost. Less than a decade later some of Chena's biggest spec builders were demoing the last of its ghost and shipping it all to Fairbanks.
It seems like the tax should go away for compact new homes, rather than become negative... [though] it would make legislation easier to pass. That way legislators can say that they aren't really raising taxes.
That's my thinking, except residences by no means need to be houses. The smallest, most energy efficient building is a multi-unit residence (apartment, condo, etc). This would incentivize more urban renewal and brownfield development, and disincentivize exurban sprawl.
We really don't need to encourage people to be building more unneeded homes
Agree, but any that are built here on out (and more will be built) should be as energy efficient as practicable. Take a look at the LEED for Neighborhood Development I mentioned above, which assigns points based on closeness to mass transit, offices, grocers, schools, and other destinations, and really drives a new development to be brownfield.
Excellent comments Gail. A large part of our suburban housing base will be abandoned and recycled anyway. Taxing McMansions seems like a good idea. But why not have a tiered energy rate structure for residential and commercial energy use, Don't make it arithmetic. Have it tiered exponentially. Then folks could decide how they would cut energy use and perhaps inspire innovation.
I'd suggest a two pronged approach is easier to sell.
1) For new housing set minimum standards progressively lower each year and that hit the zero carbon target for 2016 that the UK has already written into law. You look like you are giving the building industry time to adjust, but in reality there are major advantages to moving quicker than the minimum.
2) For existing stock set a tax on sales related to the energy efficiency of the house as it is now. In the UK all houses need an energy certificate to go on sale so the raw info is there. For those that are the most efficient there is a rebate, for those that are least there is a tax, lets say 10% either way. In net terms the two balance out to no overall revenue generation.
When the prospective house hunter goes looking the least energy efficient houses are the most expensive - forcing the seller to do something towards energy efficiency rather than just painting the walls magnolia.
For existing stock set a tax on sales related to the energy efficiency of the house as it is now. In the UK all houses need an energy certificate to go on sale so the raw info is there. For those that are the most efficient there is a rebate, for those that are least there is a tax, lets say 10% either way. In net terms the two balance out to no overall revenue generation.
This is an excellent idea. It highly motivates the homeowner to continue to improve the energy efficiency of their home.
That is one of the worst ideas I've ever seen. Demanding that a homeowner make major improvements every few years just to be able to sell without penalty is grossly punitive. It would be utterly disastrous for the market too, effectively putting marginal owners underwater and giving them an incentive to walk away.
Thank goodness such ideas have zero chance of being passed into law in the USA these days.
But that 48 percent blends residences and retail places! Can anybody dispute that our retail environment is wildly over-built in spatial terms and of generally horrible quality in terms of energy waste?
The real linchpin and #1 problem remains transportation, which is the actual largest and most irrational energy user, if you keep residences and retailers divided. And our addiction to cars is the underlying cause of our addiction to petroleum, which is the most pressing problem in terms of the risk of social catastrophe. Cars-first transportation also explains a huge share of the layout, design, and raison d'etre of the retail, manufacturing, and residential sectors.
I worry that telling people our main problem is buildings is going to let cars-first off the hook, and thereby increase the already high likelihood of delay and disaster. If we solve cars-first, we will by definition be forced to address buildings. If we address buildings, we will almost certainly continue to peddle fairy-tales about the sustainability of cars-first mobility.
I'm not saying buildings should get ignored, but don't we want to avoid lending aid and comfort to the prevailing deception that this is all about changing your light-bulbs and taping your windows?
"The real linchpin and #1 problem remains transportation"
What is a bigger problem for people:
1. Not being able to drive their car and being forced to stay home.
or
2. Not being able to drive their car and not being able to afford to heat their home.
The best current use for petroleum is making high efficiency spray in place foam insulation to Super Insulate uninsulated or poorly insulated (most of the current US housing stock)houses. It reduces energy consumption, eliminates the CO2 from the fuel that no longer needs to be burned to heat with and makes it possible for even poor people to have warm comfortable house with almost no heating bill ( And the Government would no longer have to pickup the heating tab every winter for $$Billions$$ for people who can't afford to heat their poorly insulated homes.
I worry that telling people our main problem is buildings is going to let cars-first off the hook
Don't worry, we're out to hit all the angles in this series. And my idea of a place to live is best described by J.H. Crawford at Carfree.com, an urban design approach (similar to the picture below).
If you split up buildings into residential, commercial, industrial, why not split up transportation into auto commuting, freight, aviation, etc?
Will, do you know where that picture was taken? It looks very much like Arnhem, where I spend half my time. There is a very large area downtown that looks exactly like that. I bet from the Amstel sign it probably is in the Netherlands. My guess is it's Amsterdam.
Never mind. I Googled "Cafe van Beeren" which you can read on one of the signs. It is Amsterdam.
Dude! You are also a Google Detective! :)
I hear the "Intelligence Community" is looking for smart, adventurous types.
You might even get to wear a disguise!
Just sayin' ... you can file this free advice away under "if I ever get bored with my current line of work" -- or not! :)
Yes, Amsterdam. You can find more excellent examples of how we should have built our urban areas at http://carfree.com/cpix/place.html (a glimpse of the future for the farsighted?).
There you have it. Dividing industry among the other end uses, transportation is the #1 energy user, larger than the entire residential sector!
That's an amazing and scandalous story. Unconscionable, and radically under-emphasized.
What do primary energy reduction requirements do to lot sizes? Where I live (Atlanta), the problem is more heat than cold, and most areas are heavily wooded (unless a developer clear cuts a multi-lot area, but they still grow back quickly). I would expect that in many respects this is good--deciduous trees shade homes quite a bit in summer, and less so in winter. People usually remove pines because they fall over so frequently.
If you want to have solar PV, it often doesn't work well, because many roofs are too shaded. If you really wanted an unshaded roof, you would probably need to buy the neighbor's lot as well, so you could cut their trees down. I imagine there are other lot-related problems in other parts of the country.
What do primary energy reduction requirements do to lot sizes?
Nothing. Size of a new house will be driven by primary energy reduction requirements (and fuel guzzler taxes). Location of a new home (and lot sizes) will be driven by LEED for Neighbor Development (link in article). Microclimate measures are always helpful, but there are a number of ways to reduce summer insolation heat gain, including the cool roofs mentioned above, overhangs over windows, etc, so there are a number of approaches one could take to stay cooler (and some of the approaches also allow you to generate power as well).
Around here, it can take 25+ years for a maple or oak to reach the eave of a 2 story building, and then another 15-20 to block insolation from reaching the majority of the roof, which is more that most PV lifetimes. And PV arrays can be pole mounted where there is sun access.
If an existing house is already sheltered by tall deciduous trees, then the next best step after weatherization (and replacement of HVAC components if old) is to purchase 100% renewable electricity from the power company. We'll be getting into building renovation in more detail in future articles.
Land use planning and surface heat island formation: A parcel-based radiation flux approach
Atmospheric Environment 40 (19) 2006 Pages 3561-3573
Brian Stone, John M. Norman
From Stone and Norman (2006/paywall):
* A 25% reduction in the area of lawn for the average residential parcel would reduce heat emissions by 13%
A 25% reduction in the area of impervious cover for the average residential parcel would reduce heat emissions by 16%
A 25% reduction in the area of lawn and impervious cover would reduce heat emissions by 28%
The combination of the above strategies with an increase in average parcel canopy cover from 45 – 60% would reduce heat emissions by 40%
As the previous article showed Obama working the soil on the White House lawn, this article made me wonder about the energy status of the White House. Does anybody know what it is? It's an old building, so it makes me wonder how efficient it is.
Perhaps this could be a first move for Obama. Superinsulate the WH, install some ultra-efficient heat pumps, and make other fixes so that the WH complies with LEED or other high standards. No time to start like the present, and no place to start like your own home.
I think he did make some mention of starting with Government buildings.
White House Solar Panels: What Ever Happened To Carter's Solar Thermal Water Heater? (w/VIDEO)
I feel that the 'Organic Garden on the WH Lawn' or a big Energy Buildout to the structure would just play as a political stunt, compared to a real Dollars Investment in Nationwide Superinsulation Programs, Smart Renewables (Starting with a LOT of Solar Hot Water, say), and a doubling of whatever plans are there now to make public schools and muni buildings in EVERY community become those examples of Energy Efficiency.
A 'Fireside chat' (or many) that talks about taking the Long View on energy use and investing in Insulation, HeatPumps etc.. really ADVOCATING for a serious push on all our parts for these goals would seem more useful and less gimmicky. Then, have the WhiteHouse improvements be the supporting cast to that.. make it known, but trumpet the actual information and philosophy, not the showpiece. Show it happening on Main Street and at City Hall to preclude the charge of 'Precious Elitism' that it would get at 1600 Pennsylvania Av.
Bob
While all of the comments here have the same goal, reduce energy consumption, they run aground on the same shoals, which is we are desperately short of well understood Life Cycle Analysis data. So for example, how much should home owners invest to reduce their energy consumption before they reach the point of diminishing returns? We need an analytically based plan to get from where we are right now, to sustainability, based on a series of scenarios, from Peak Oil in 2030, to Peak Oil in 2005. Then from that, determine what our policies should be, and where to spend the money. So the question would become, not how far can the building efficiency targets be pushed, but what do they need to be to achieve the necessary reductions, based on the acknowledge Peak Oil date and GHG reduction goals.
Part of the problem is our elected officials are motivated by different issues. Some want to do right, regardless of the political consequences, while others will follow the their voters’ wishes, campaign contributors & lobbyists dictates, or knee jerk dogma like the obsession that the market will always save us, regardless of the conditions. As a result, we don’t have a plan, we have chaos. How many of you would bet that ethanol subsidies will be dropped because of low EROEI, with 82 senators representing 41 corn producing states during a severe recession/depression?
From a practical point of view, if you want to replace 80% of the 56 Quads of coal and natural gas we consume annually by 2050 with renewable energy, we will need to build approx. 17,000 Enercon-126 (7 MW’s) sized wind turbines a year, every year, for 40 years to accomplish the task (about 680,000 total). That’s 6 times more wind capacity each year than was installed world-wide in 2007. It would cost about $70 to 140 billion/year and employ between 450,000 and 900,000 people. Right now, I don’t see any plan to build at such a pace (6.5 per week in every state for 40 years, or just a little under 1 per day nation-wide). Obviously, if we can cut our residential energy consumption in new buildings by 75%, then we would only need to build maybe 10 to 15,000/year, which is still way beyond what anyone is suggesting.
Since I was not elected President two months ago and I am not an insider, I do not want to be too critical of Barack so far. I also don't know what his administration has up its sleeve after the stimulus plan. But from my perspective, either they don't realize the magnitude and timing of the problem, or they don't have the political capital to propose the programs they really want. As a result, my feeling is that our institutions will not address the problem successfully until another crisis and shock puts everyone on the same page. Only then will we finally allocate the necessary resources and it will probably requre WWII type programs because of the time limitations.
Enercon-126 - Bigger than the average bear....
Enercon 126 prototype
Enercon E-126: The World’s Largest Wind Turbine (for now)
"if you want to replace 80% of the 56 Quads of coal and natural gas we consume annually by 2050 with renewable energy, we will need to build approx. 17,000 Enercon-126 (7 MW’s) sized wind turbines a year, every year, for 40 years to accomplish the task (about 680,000 total)."
I haven't checked your numbers, but even if they are accurate, the statement assumes that wind will be the only element and that there will be no new efficiencies in that technology either. Most here seem to agree that we need to vastly decrease the amount of energy we use, especially since so much of it is wasted so foolishly. I think we should aim for 80% reduction of energy use (if not more). Supper insulation and organic farming will greatly reduce the needs for natural gas, and are just smart to do anyway. Insulation and other measures noted here could also greatly reduce AC use, a huge draw in summer. Add some solar PV in the mix and you further reduce what wind will have to carry.
I'm not trying to minimize the scope of the problem by any means. It is still vast almost beyond comprehension. I just find when people say things like "It would take X amount of Y technology to replace all our current use of Z", it is almost always an oversimplification that overlooks important factors.
And it may take a major disaster to move public opinion, but disasters are never sufficient by themselves. People have to have an accurate picture in their heads (even if if has to compete with other, less accurate pictures for a while) about why the disaster happened and how to prevent it in the next time. Otherwise they will just return to BAU, "'cause, hey, sh*t happens, ya know...."
Hi dohboi,
I agree with your comments. We will need more than just wind. What I wanted to do was begin to put a magnitude and dollar figure on what it will take to achieve sustainability or in this case, 80% CO2 reduction by 2050, and just how far off in scope the current governmental plans seem to be. Wind is also cheaper than solar by a factor of 2 to 5, but I also have not worked in the additional grid costs. For wind, you can do the calcs yourself by go to the EIA (http://www.eia.doe.gov/aer/pecss_diagram.html), and downloading their data on energy used per year. I then use http://www.onlineconversion.com/ to convert between kWh and Quads.
But one issue that is currently unknown is just how much we can reduce our consumption over the next 10 to 20 years and at what cost. I'm assuming that some balance will be achieved between generation and efficiency reduction costs. I don't profess to know where that will be. For urban dwellers such as myself, I could be forced to take a bus, and probably drop my gasoline consumption by 75% to 90%. However, for the guy who lives on a farm in Kansas, needs a 5 or 6 liter pickup truck, and drives around his 10 ac. farm and 10 to 20 miles to the nearest town, he probably does not have that option.
As for housing, I live in a 100 year old bungalow in Los Angeles, and there is no place to super insulate anything. I've had the walls filled with insulation (R7-R9 rating) and to do any more will be very expensive. It would be cheaper to add a 5 kw solar array at market cost of about $35k (16 after all the rebates) and use it to run the AC(SEER 13), which is a 30 Amp power hog.
Nicely put. I think that we city slickers need to be finding alternatives to our high-gas-usage ways so that there is enough left over for farmers (along with emergency vehicles and a few other uses). I'm generally not fond of bio-fuels, to put it vary mildly, but bio-diesel for farms may be worth while.
I'm in an 80-year-old bungalow in Minneapolis, and high expense and massive inconvenience (and a bit of laziness/busy-ness with other things, I must admit) have kept me from doing all I could to maximize insulation. I think both punitive and supportive incentives from gov could do much to move many of us in the right direction. Education is, of course, key too.
Innovative approaches, like just adding high-R value siding on the outside or high-R value drywall on the inside of walls, may be needed. I'm not handy/smart/informed enough to know whether building hay-bale walls around an existing structure would be feasible or remunerative. The architects that I've talked to that specialize in this kind of thing say it would be very expensive. But maybe if it became commonplace, some of that expense would come down?
Is high-R value drywall something that actually exists? I have never heard of it, but I do live at the end of the road so to speak.
Pragmatic,
I think you are making a common mistake, wind nuclear and solar don't have to replace the 50Quads produced by coal and NG they have to replace the electricity generated by these FF, approx 320GWa(nuclear, hydro and wind already account for 28% of the 460GWa). This would require either 1000GW capacity wind or an additional 30GWa hydro, 300GW capacity solar(150GWa) and 420GW capacity wind.
To build 1000GW wind capacity would require 130,000 of the 7MW turbines( 3,200 a year over 40 years) very realistic. If the 420GW mix of wind , together with solar , hydro (and nuclear?) would be adding 10GW of wind capacity per year( compare this with the 7-8GW added in US in 2008).
Lots of realistic proposals have been put forward for wind to replace FF in much less than 40 years.
Good point Neil, you raise a very important issue when discussing replacement of fossil energy with renewable energy / efficiency we need to look at end use energy not primary energy inputs.
Since centralised power plants effectivly lose 2/3 of the primary energy in conversion and transmission of the electricity, replacing them with wind and combined heat and power plants should mean much lower primary energy inputs to the system (and also lower energy imports for a country chasing declining net exports of oil / gas / coal)
The US could be installing 10GW each of wind & CSP and breaking ground on a similar capacity of nuclear power per year if it had the inclination.
4 Million cars assuming 100kW per unit is 400GW of engine power which could be diverted towards CHP systems, as no one is buying the cars at the moment.
Compression ignition engines can be co-fired on natural gas, and microturbine technology is improving all the time. Biogas production already well developed in Germany, and can 'complete the loop' on nutrient recycling and biofuel production, making use of a wide variety of feedstocks including seaweed, prickly pears, fast growing grasses and manure.
Using half as much energy twice as efficiently, stretches our fossil fuel reserves and means much less alternative energy is required to provide the same quality of life.
CHP at the home level may not be as practical as a neighborhood scale system. 100 homes sharing heat and power from 10 nat/bio gas fueled engines would have a redundancy and economy of scale the a single independent engine would not have. Also an adsorbtion based cooling system is more practical at sizes too big for individual houses.
The biogas can come from sewage / food waste digestion with a top up from fast growing grasses.
Also the solar seasonal thermal storage systems start to look like a good option at this scale.
IMO there is no reason why the 10 CHP units can't be plugin hybrid cars, small engines designed to generate electricity could find uses as CHP units and range extenders for battery electric cars.
CHP at the neighborhood level requires easements, condominium agreements, and other details that will be very hard to set up for existing housing.
Freewatt (formerly Climate Energy LLC) has drop-in CHP systems in residential sizes.
That's why I see the neighborhood concept being applied first to new developments. Neighborhoods and even entire towns that have been devastated by natural disasters that require public funding might be where it could be experimented. A large amount of extra underground plumbing would be involved.
With the building bust and credit crunch, what new development is going to take on the extra capital cost?
If you are interested in larger systems, apartment buildings with central boilers would be the best target for the first installations. But beware of relying on anything dependent on natural gas, as the price looks to become very unstable. This is why I think CHP systems should be designed as modules with a relatively short service life (15 years or so) which can be swapped out for something else like heat pumps at the end of their usefulness. Capital input should be kept low, so that a change in the economics of natural gas does not result in large stranded costs.
If we are looking for something for Detroit's idle plants to do, CHP systems are probably a good option.
For people interested in retrofitting their not-south-facing homes for deep energy reductions (70% - 90%), what or who would you suggest contacting? Local contractors, including "green" companies interested in insulating your home, etc., don't seem to know that much -- they help with the very first stage, like insulating your attic and sealing your house, but not much else. I notice the the Passive House Institute doesn't seem to have much, if anything, relating to retrofits for people in the U. S. A. Should we scrape our homes and start over, or what?
First you need to perform an energy audit, starting with your utility bills.
Use one of the utility or government websites that allows you to do energy audits or purchase a copy of Manual J. There are also spreadsheets that based on Manual J. Again, check with your utility, the internet, or an architectural standards book
The utility analysis will include an estimate of the amount of electricity used for appliances and lighting.
You can calculate the savings from making various improvements, such as adding insulation, adding cellular shades and replacing old single pane windows.
Window replacement as a do it yourself project can be done for half the cost, or less. Good 3’x5’ replacement windows cost about $300, based on fiberglass frames with Low E coating and argon fill.
Cellular shades cost about $150 for the same size window. I would recommend these in northerly climates.
Blown attic insulation cost in the range of $500 per 1000 sq ft, depending on the thickness you add. There are also foam coatings, which are much more effective, but more expensive and may be flammable.
Consider replacing old HVAC systems, especially if you know that they are not efficient.
Unless you have extremely inefficient house, with little insulation and large single pane windows, you will be lucky to get even a 50% reduction. But for a typical energy inefficient house, the comfort level from an upgrade will be surprising.
Other than adding a sunroom or south facing windows, it is difficult to do more than what I mentioned to an existing structure, at least
without it being cheaper than building a new.
First you need to perform an energy audit
Absolutely, and I agree with all of the other recommendations above. There could be other recommendations on a case by case basis. While insulation, infiltration reduction, and good windows are the first place to start, there are a couple of interesting things to do that can provide winter heat gain without substantive cost or structural changes; my next article in the pipeline will provide the details.
Thanks for the advice, which I have mostly already taken. I've pretty much gotten past the first stage: the energy audit, the blower door test, infrared scanning for leaks, sealing of air leaks, new windows, lots of exterior insulation, and more, and have cut my natural gas usage to about 55% of what it was before:
http://compassionatespirit.com/Superinsulated-Retrofit-Overview.htm
I'm going for 75% heating cost reduction. I'm collecting possible sources of additional information. What I've come up with so far is the Passive House Institute, previously mentioned, which probably do not have locally available consulting services, but who have some software for sale at this location (costs $225):
http://www.passivehouse.us/passiveHouse/DesignTools.html
Then there's Thousand Home Challenge here, which is not a source of information itself, but who are themselves gathering information:
http://www.affordablecomfort.org/images/Uploads/thc_description_9_18_08_...
You can also download some software from Natural Resources Canada at:
http://www.retscreen.net/ang/home.php
Do you know of anything else? There do not seem to be any clear-cut answers for those interested in deep energy reductions.
Keith
What efficiency rating does your furnace have?
What are the temperature and time settings for your setback thermostat?
I would suggest passive solar input as an additional means to further reduce your heating costs. Your house appears to face East, or slightly East-Southeast. What kind of windows do you have on the south side?
Thanks for your interest and comments!
We have a 90% gas furnace. The thermostat is 68 F during the day, 62 at night and when we're not around (and it almost never gets down to 62, maybe once or twice a year on the very coldest nights).
Yes, you're right, the house faces East and West, not South, so we've got exactly the wrong orientation -- most houses in Denver are that way, because contractors built houses with a "view" to the west where the mountains are. We have one large window on the south and a full-length window in the south door. A second window on the south is technically possible but would involve massively remodeling (or shrinking) the kitchen, probably a new stove and oven, and somewhat changing the internal architecture.
I have given some thought just to reducing the thermostat -- I talked to someone who has it set at 55 F. She uses oil heating, lives in a colder climate than I do, and uses more oil for driving (which isn't much either) than for heating. I've also thought of just having some other people move in with us, which would dramatically reduce our per-person heating costs instantly. But at this stage I am interested in the physics of the situation rather than the personal adjustments.
My thought, which I recently put on my web site, is to look at the porch steps and the thermal bridging thereof. Or maybe, as someone else on TOD suggested, the air exchanger is oversized. Or a "zone" system for heating, leaving parts of the house unheated.
Some things I am suspecting, though I have not seen anyone brave enough to put it in print yet, is (1) that small things matter more in a high-insulation house; the house needs not just to be tight, but tighter than tight; thermal bridging has to be absolutely eliminated, etc. etc., so that things which have little effect on heating bills in a "normal" house have an exaggerated effect in a high-performance house (or a house aspiring to be high-performance). And that (2) high-performance retrofits are outside of the range of expertise of virtually all contractors and energy experts in the USA, even the "green" ones who do the E-star ratings and blower-door tests. The critical mass of the number of people interested in this sort of thing is still too low. It was not my goal to become an expert in this field; I just wanted deep energy reductions in my house.
Another problem is that going forward (having made a number of high-cost changes to this house already) I want to have a good idea of the energy reduction for any proposed change. I like the idea of another south-facing window, and my wife likes south-facing windows, but this would be quite expensive. Demolishing the porch steps and areas where the porch connects to the house (thermal bridging?) and putting something else there would probably cost a lot less and might have a bigger impact. But no one can say. That's why I'm looking at getting this Passive House Institute software. Better would be a consultant that actually knows what they're doing and has experience with superinsulated retrofits and could say, "oh yeah, in your situation probably most cost-effective energy reduction would be to do X."
Keith
A second window on the south is technically possible but would involve massively remodeling
One tack you could take would be to build an inexpensive solar windowbox heater for the one window you have on the south side. I have an upcoming article on this, but you might want to consider building one (even this weekend?), as this would require zero house modification, and it could also be used as a solar food dehydrator for your garden and fruit tree produce.
Another approach would be to build a thermosiphon wall heater (examples [1] and [2]), depending on how much space you have on the south wall. Consider venting it to the outside in the summer and/or incorporating an overhang or retractable awning.
A key point in this discussion is this: whether retrofitting present structures or building new, we need to have a "Cradle To Cradle" design paradigm.
I am using insulating materials so that they can be easily removed from my old house if it becomes non-viable.
If we can create safe, portable insulating solutions we will avoid toxic waste in terms of whenever a structure must be destroyed or drastically remodeled.
I have used some foam panels as well as walls of tightly-shelved books for insulation and thermal mass. These can be taken down and moved around at need, and the books can be read as well. (The insulation can be read as well on one side, but it is repetitive and gets boring fast for me.)
Anyway -- mobile, portable solutions may be more important as the chaos of climate changes, economic collapse, and other stupid human tricks tend to increase over the next decade.
I always like your ideas, Beggar.
I've been blowing cellulose (recycled newsprint, by the look of it.. homemade blower from old Political Roadsigns! Politics works!) into our 2" deep plaster walls, and have been thinking about what to add outside or in that might continue to build on this process. For interior, I'm thinking of making some hanging 'Corner Bookcases' for one room, which will have Foam Insulation as their backs..up against the wall, possibly sealed around the edges. These would help with the worst thermal bridging at the corners and hurricane braces, but as you've said, still be removable for future homes and responsible disposal or reuse of the PolyIsoCyanurate material. For areas of wall between windows, I'm chewing over what will appear as Quilts/Tapestries to the occupants, but will also serve to augment the insulation.
My Exterior is Asbestos Siding which is too $$ to get rid of as yet, but I'd love to come up with a version of the 'Sips' (Structural Insulated Panels) idea that would combine both the insulation and the Exterior Facing, to make such a retrofit easy, sturdy and possibly Removable/Workable, instead of having to kludge a layer of siding onto a foam that won't hold nails, or would just be trashed and perforated in the process..
From Cradle to Cradle, Remaking the way we make things - Great Book, and a fine inspiration for how to be designing our next stages!
( William McDonough, Michael Braungart )
Bob
I know a reputable builder who also has the same approach. My thought is to carefully research those areas to be the most promising against a number of criteria, though being able to hedge one's bets is always a handy insurance policy.
Bob and Will -- "Cradle to Cradle" has been an important book for me. The idea expressed is simple and essential if we intend for any of us to survive for more than a few decades, I guess.
The SIPs idea also intrigues me.
I believe that the more government can intervene to help people be creative with this, the better at this point. We need to explore a variety of approaches at a variety of levels.
I do think that as homeowners we can build fairly simple and relatively safe alternatives. I like the insulated corner bookcases, wall hangings, and window quilts or insulated shutters.
I especially like the idea of adding a layer of awnings and even framework for growing leafy shade plants around the house for late-summer, and then for attaching some sort of collection of used windows for a greenhouse effect in winter. I hope to explore the beginnings of such a project this summer.
I've been dumpster-diving at some remodeling projects in the wealthier parts of town for some materials.
A couple of contractors have encouraged me. One gave me his card and asked for mine. He will call as he comes across materials I might be interested in, and we may also connect to discuss ideas.
This kind of building networks in neighborhoods can be helpful, also. We can build relationships that otherwise would not have been formed.
ICFs lack weather protection for the insulation and insulate the thermal mass, SIPs lack thermal mass, and tilt-up concrete lacks integrated insulation.
It looks like there's an opportunity there for someone with the engineering chops to get it all together in one panel. I've got some ideas, but nothing that I've got the experience to evaluate or the resources to pursue.
I love posts like these, which address energy efficiency at home. Or in homes not yet built.
I get the impression that the information is geared towards construction in temperate, not tropical zones.
In tropical zones, I think that one is more interested in cooling than heating.
Can anyone point me to examples of low-to-zero net energy buildings in tropical zones?
Or have I got hold of the wrong end of the stick?
Do what they do in Matmata, Tunisia.
Can anyone point me to examples of low-to-zero net energy buildings in tropical zones?
Are you wanting to use A/C, or prefer to tread lightly?
I'd like to avoid the use of electrical power as much as possible.
What is your location, so I can look up the weather data? Are you planning on building new or renovating?
Location is around 17° 9′ 23″ N, 104° 8′ 44″ E
I would be building from new. But this is still very hypothetical. I don't want to put you to any trouble.
Some weather data is available. No humdity information was readily available, but given the location and the amount of rain in June, July, and August, we should assume humidity is high.
January - December
High-Temperature ( F ) 84 87 92 94 92 89 88 87 88 88 86 83
Low-Temperature ( F ) 59 64 70 74 76 76 75 75 74 71 66 60
Precipitation ( in ) 0.12 0.83 1.85 4.21 9.45 18.74 17.95 23.98 10.98 3.07 0.31 0.04
Average-Percent Sunshine 36 30 31 29 27 18 19 17 23 30 33 36
I agree with Paul's recommendations, and depending on your temperature/humidity acclimatization, I see three basic options, all of which include careful shading (not unlike a cracker house) and high thermal mass;
1. No A/C, with extra careful shading and ceiling fans, taking advantage of night temperatures in the 70s to purge heat from the house's thermal mass for the next day. This will mean enduring some humidity, though the temperature can be moderated with thermal mass. Windows could be closed before the day begins to heat up, opening later when the early evening temperature drops to the house temperature.
2. High efficiency ductless split A/C units with high insulation and high thermal mass in the house, run primarily at night to cool the thermal mass and take advantage of the lower ambient temperatures.
3. Ground source heat pump with high insulation and some thermal mass in the house to moderate temperature swings and keep cycle times high to ensure highest efficiency.
I've no doubt there are other approaches as well.
The daily low temperature is indicative of high humidity, which is also indicated by the exceptionally high monsoon rainfall. Also the difference between day and night temperatures is low.
The degree that thermal mass helps is proportional to the day/night temperature difference. I'm guessing that in this climate thermal mass would save about 30%, versus 50% in Atlanta.
And unless thermal mass is AAC, which is insulating, there may be a condensation problem. All closet doors should be louvered, and it may even be necessary to have cabinet doors on external walls louvered to prevent mold.
This climate is somewhat similar to Louisiana, where I grew up. The old plantations used West Indies architecture, with louvered porches (bottom 2 meters open) for shade. In summers they slept outside under mosquito netting.
http://www.nps.gov/history/nr/travel/louisiana/okl.htm
You can see the upper porch is completely louvered, and the lower porch, where the stairs enter, has 2 meteres unlouvered.
Bedrooms were in the upper levels. Dining and storage were on first level.
(Something like 10-20% of the people living in these plases died from mosquito transmitted diseases, particularly yellow fever.)
Location is around 17° 9′ 23″ N, 104° 8′ 44″ E
http://maps.google.com/maps?ll=17.156389,104.145556&spn=0.1,0.1&t=h&q=17...
I would be building from new. But this is still very hypothetical. I don't want to put you to any trouble.
After thinking about it, your location may be good for insulating concrete forms (ICF). The insulation will prevent the condensation problem.
To use ICF you need a concrete company that has a small concrete pump and access to a superplasticizing or water reducing agent. That allows the pumped concrete to flow easily in the forms without having to be waterd down and loosing it's strength.
The superplasticizer only works for about 2 hours before the concrete gets thicker, so you may need small batches, assuming you will be having it delivered by truck and pumped.
The inside walls can be finished with drywall/gypsun board. The outside with fiber reinforced cement (Hardiboard).
Also, you may get minimal benefit from a geothermal system because of the near constant year round temperature.
It is difficult to get zero or low energy consumption in tropical areas if there is high humidity.
One thing I recommend is a metal roof with a reflective coating. You can reflect 70% of the sun's heat with a white, specially painted roof. Also, have white exterior walls.
My home is in a humid sub tropical area along the US Gulf of Mexico. I need both heating and cooling, amounting to about 8500 kw-hr/year, with half of that being for lighting, appliances and computers. Heating and cooling are from a heat pump. Size is 195 sq m.
I used aerated autoclaved concrete, AAC, which is completely resistant to humidity and termites. My walls are .3 meters thick. AAC is a good insulator, and being massive, minimizes day and night temperatures. I would not particularly recommend it in earthquake zones. There I would recommend ferro cement, which you can look up on youtube.com.
I have small, high windows on east and west side, just enough to allow a little light in, and some cross ventilation. I also have a wide overhang on the south side of the house, with windows starting one meter above the floor.
The north side has windows from .5 meters above the floor.
Consider a geothermal heat pump if you need much air conditioning.
Thank you all so much for your valuable input!
Will, you wrote
Assuming the $1 million is real, not inflation bloated, your claim means a compound annual return of 12% over 20 years. It seems like many projects would already be incorporating green building infrastructure if this were a sure thing. What assumptions have made re: energy prices?
Paul in Nevada
Will, you wrote
*With regard to commercial and government buildings, an initial upfront investment of up to $100,000 to incorporate green building features into a $5 million project would result in a savings of at least $1 million over the life of the building, assumed conservatively to be 20 years.*
Assuming the $1 million is real, not inflation bloated, your claim means a compound annual return of 12% over 20 years. It seems like many projects would already be incorporating green building infrastructure if this were a sure thing. What assumptions have made re: energy prices?
Paul in Nevada
I obtained that from ;
"The Costs and Financial Benefits of Green Buildings: A Report to California’s Sustainable Building Task Force", Greg Kats, Capital E, 2003, pg ii.
which includes other data points and findings, such as;
Thanks Will,
I will take me some time to digest this.
From an equity point of view, assuming a 2:1 debt equity ration with debt at 7%, green infrastructure would be s strong winner. No need for government subsidy or mandate.
Thank you for the article. I think your suggestions for a government mandated move to better (enery) architecture will not work. it may work first at a commercial and industrial level. But here, energy future energy costs estimates are paramount. My local utility sees natural gas at $8 mmcf for several years. I think they are in for a rude awakening.
The resedenitial market is still hooked on the per month cost, amortized over whatever for the leverage.
Rather than quick fixes through sudden switches to renewable, you point the way long term energy economics. My bias is that petroleum cannot be replaced in the near term. An energy scarce future.
Please make yourselves aware of Phase Change Materials.
http://en.wikipedia.org/wiki/Phase_change_material
I was the electrician at Kalgoorlie Hospital. Their electricity bill is in the region of A$5 000 000 per annum. 95% of this we found to be air conditioning and hot water. When it got too cold the hospital was heated with steam, an additional expence. The nurses would tolerate a 2degC band.
I tried to persuade management to install Phase Change Materials and save 80% of the electricity bill. Not to mention green house gasses from the 5 MW Thompson boilers.
They stuck their fingers in their ears, and treated me as public enemy number 1.
The perfect bureaucrat never makes a mistake so never takes a chance.
Lots of luck, Leroy
Agree completely. Phase change materials (PCM) are a moderating thermal mass, as noted in our previous article in Passive Solar Design. This is an area of thermal mass research and development that could be instrumental in enabling energy saving renovations.
All,
If you want to bring change in, you need to study the human psyche which is not logical, despite what we like to think.
You need to appeal to emotions, and power in bureaucratic organisations.By all means, present the facts, the business case, then appeal to the ego. Go for the juggernaut of pysche - , understand the organisational goals and pitch to that.
Present directors are obliged to add value to shareholders - private or public. It is their legal obligation.
So remember that,rail against if you like, but these are the facts, so work with them. Try to get directors and management to ask "what if" - this will open cognitive processes to change, show justification by poitning to short term as well as long term goals and savings. Long term will lose unless you can show quick gains short term.
As much as I agree that the building sector is the "low hanging fruit" in conservation, I would humbly submit that the picture is actually much more dire than the article lets on.
Example: go here: Bloor Street, Toronto ON.
not far from where I live.
My home is VERY typical for this area: it is made of brick, load bearing dual course, 2.5 stories tall. The walls are made of plaster lathe, the floors are hardwood. The HVAC is gas heat w/ outdoor AC box. Gas hot water heater. The layout is standard: you come in tye front door to a foyer and stairs to the second floor. To the right is the living room, and beyond a dining room. Next to the dining room is the kitchen and beyond the dining room is a small back room. Upstairs are 3 BRs and a bathroom. The top floor is a small bedroom and a sitting room that goes to a small deck. The basement isn't finished, but it's not "packed dirt" either. My neighbours house is nearly identical, as are almost half the homes on my block.
Toronto is filled with THOUSANDS of homes like this, and converting them to some kind of "solar" home is a fool's dream. These homes will require extra-solar energy to keep warm in the long cold winters and cool in the muggy stupid summer. Sure: we could sell this place and buy some land out in hell - I dunno - Prince Edward County or something, and build the "Solar Home" but we work in Toronto, so any energy savings in the home would get dumped into transportation. As it is, I take the subway to work...
MILLIONS of people live in such homes. And there are millions of other homes like it filled with MILLIONS of people wondering how they're going to keep warm in 20 years.
Our plan?
Almost 1/2 the electric in Toronto is from hydro. So, for this city, electricity is the future, and I am supporting and working to guide local PTB into wind and solar decisions. I am not opposed to nuclear, if it can be done with reduced/no waste, such as this hybrid system.
So, our plan of battle:
1. get an energy audit from the govt (once complete, this gives us the ability to tap into gov't subsidies for greater efficient systems, and provides a roadmap for improvement.)
2. see what the audit comes up with, but I know enough what it will say, which leads to step 3...
3. seal leaks, swap out the remaining incandescents for CFL
4. insulate the basement to keep the main floor warmer
5. better window treatements (such as insulated curtains).
6. buy an electric water heater (we don't get enough sun for solar)
7. get an insert for a really good wood burning stove
8. Supplement the stove with some kind of a heat pump (I would LOVE to put in a geothermal device, but our yard is too inaccessible and too small - again, typical of this area)
9. renovate the interior of the house so we might loose 2 inches all around the exterior perimeter, but it would be filled with insulation foam. This will be very expensive, as we love the woodwork of the house.
10. Along with #8, I have designed "glass walls" that can be clamped and sealed over windows to add another layer of insulation over the windows. These could be removed at springtime and stored in our basement, which is already being developed to act as "food locker", so we can more easily survive short failures in delivery systems.
11. We are looking to adopt a new "look" in rugs, which is LOTS of them. We bought a few more and will be scattering them about. It looks haphazard at first, but once you get past that it's very warm and pleasant. They can also be periodically rearranged and reordered, to make different appearances and cut down the necessity of constantly cleaning them (basically BURY them under each other until you can't do it anymore ,then clean them...) Along with this we'll be putting tapestries over the walls to create another layer of *breathing* insulation. I am already designing these tapestries. OF course, if my daughter has any say we'd have walls filled with The Lady and the Unicorn...
Sigh...
In the end, with that we should have (we hope) a very stylish and extremely efficient home.
This of course is a very "middle class professional" approach to the problem, and I am VERY clear on my point of privilege in that regard. I understand that most people won't be able to design their own tapestries...
That said, I smell "opportunity" for someone to make insulated tapestries at a low cost for poorer people to put up on their walls. If YOu mount two back to back and hang them fro mthe cieling, about a cm apart, that could work as a very cozy room divider.... And I would be happy to be at my friend Dave's house (he works as a substitute teacher and his wife works in sales - they can't afford a lot of things) amid specially insulated tapestries of Unicorns made in Mexico or China...
I agree there are things we can do to get us below the depletion curve, but we have to be very clear on the enormity of the scale of the proposition, and we also have to be very clear that as this is a global emergency, each step also is goign to be global. So, when people say "Nuclear power" that means Nuclear power for N Korea, Iran, Zimbabwe, and Nigeria, and Cuba and Afghanistan. Saying "Oh, I'm a Westerner, and so I can have nukes, but you're not OECD or G20, so you don't get a nuke" isn't going to fly. We're all in the same boat, so whatever superior systems one region uses will be demanded by all regions.
So it won't be just little ole me and my fambly buying a woodstove for the living room - it's going to be MILLIONS AND BILLIONS of people buying woodstoves for the living room. It's not going to be 3 tapestries in our home, it's going to be MILLIONS AND BILLIONS of people using organic woolens as wall insulators and decorations. etc. and so on.
So, while I think the "Oh, let's all build solar homes" is a good impulse, it is not any kind of a solution. All the good places are taken and the sunk cost in the infrastructure cannot be undone. We need to find ways to modify our present infrastructure to keep it running under the depletion curve, and then use economic and social levers to reduce population pressures. If we can do that, we will roll out of the petroleum age, but not into a transit camp in Montana where we freeze to death or die alone from pneumonia or disappear in the radiant flash of a nuclear weapon. Die we must, but how we do it is one of the few points of dignity left in a world of vanishing resources.
Core to this transition (besides the engineering) is the Media and Communcations systems. But that's a subject for a PhD soemwhere....
Good Details, Stuart.
One other option to keep in mind is that the ground under your under-developed (and sadly NOT earthen, in this case) basement runs at a cool median temp all-year round, and could be tapped without the full investment of Heat Pumps, by creating an Air Intake Sinus that would offset both Heating and Cooling requirements for the house. Sometimes called 'Cool Tubes', and a much less sexy form of Geothermal than most folks ever talk about now. (Summer Condensation and subsequent potential for mold must be considered when installing these)
Bob
Toronto is filled with THOUSANDS of homes like this, and converting them to some kind of "solar" home is a fool's dream...(we don't get enough sun for solar)
We realize that not all solutions will work everywhere. Making homes energy efficient is extremely important, and those who are in areas that could utilize solar want to be able to design renovation in a systematic way, so we are providing the basics in solar as a prelude to the energy efficiency improvements. If we had started the other way around, people likely would have said, "yes, but what about solar enhancements, shouldn't I be considering them at the same time?"
We will get to all these points; time was invented so that everything didn't happen at once.
Your stepwise approach is logical, though #10 talks about 'glass walls' that could use some clarification.
I would love to say that all 6+ billion people on the planet would live at the same level, but I don't see that happening, at least not in a dozen lifetimes or two. Nature doesn't negotiate, and quite frankly, some nations we consider ourselves superior to now may not go through the same devastating collapse pains we might.
So, while I think the "Oh, let's all build solar homes" is a good impulse, it is not any kind of a solution.
For you, perhaps not; for others, perhaps so. I welcome differing opinions on this matter. Every person must chart their own course and determine their fate for themselves and their family. Those that do so in concert with others (i.e., community-based and higher levels) will have the best shot.
Mr Stewart wrote:
We realize that not all solutions will work everywhere.
Prima facie.
Making homes energy efficient is extremely important, and those who are in areas that could utilize solar want to be able to design renovation in a systematic way, so we are providing the basics in solar as a prelude to the energy efficiency improvements.
Yes, but you're ignoring all my basic points. sure: if I had access to open land with a stand of woods and a stream nearby - I'd build a solar home - that's a no brainer. The problem is, and I'LL REPEAT MYSELF, which I hate doing:
All the good places are taken and the sunk cost in the infrastructure cannot be undone.
Sure, I can go buy some land out in the middle of nowhere, but getting to work would be expensive, bordering on impossible, and getting the materials to build such a thing out there would be very energy intensive and hard to repair. So, the good places are taken. And it is taken by a massive multi-trillion dollar investment in infrastructure built since WW1 and even more since WW2.
I would suggest that the percentage of people your plans offer solution is tiny, bordering on microscopic.
The REAL innovations are going to be in low cost housing renovations that can be accomplished quickly in an urban environment using the inferior infrastructure as presented.
If we had started the other way around, people likely would have said, "yes, but what about solar enhancements, shouldn't I be considering them at the same time?"
I would tell them, No. solar enhancements are only of value when you have reduced your load as much as possible, and THEN you can design your solar enhancements at a commensurate scale. Unless of course you're a trust funder who can build a solar home at will on any piece of undeveloped property.
We will get to all these points; time was invented so that everything didn't happen at once.
Agreed. However, i would suggest that MASSIVE conservation is the thing to focus on immediately. This will extend out petroleum plateau further and allow us to use that energy to develop better technologies which can then be implemented to match the reduced load.
Your stepwise approach is logical, though #10 talks about 'glass walls' that could use some clarification.
Thanks! I appreciate that. About the glass walls-
I'm putting together one for now, to see how it works.
The theory:
1. double paned glass makes a better insulator than single pane.
2. There isn't much to look at during winter time, but getting light and heat in is a "good thing".
So: build a frame of wood, and then fix/seal fairly thick plexiglas on both sides, creating a roughly 1 cm space between.
Drill through, bolt it together and counter sink it. Then put wood stripping around it and custom cut these "windows" to exactly fit the window it covers. Weather stripping tape can then be applied to seal whatever cracks arise.
So, rather than cover windows with sheets of plastic film, these create a more durable and aesthetically appealing cover that can be removed and stored during summer. Put them up in late November, take 'em down in late March. Used in combination with thermal insulated drapes: a winner, IMHO.
Cheap and easy to build. the plxi will tend to cloud over the year, but, hey - it's winter. "Look - outside. Snow. Gee. What a surprise..."
I would love to say that all 6+ billion people on the planet would live at the same level, but I don't see that happening, at least not in a dozen lifetimes or two.
I would submit NEVER. however, access to electricity != everyone living at the same level.
Nature doesn't negotiate, and quite frankly, some nations we consider ourselves superior to now may not go through the same devastating collapse pains we might.
This is all true. Which is why this kind of discussion is so vital.
Thanks for your thoughtful response.
if I had access to open land with a stand of woods and a stream nearby - I'd build a solar home - that's a no brainer. The problem is, and I'LL REPEAT MYSELF, which I hate doing: All the good places are taken and the sunk cost in the infrastructure cannot be undone...I would suggest the that the number of people your plans support are tiny, bordering on microscopic.
These article series are not simply about building a new passive solar home off out in a greenfield somewhere. All we we have covered so far is the basics, which can be applied to new construction in a greenfield, new construction in a brownfield, and renovation of existing buildings. If you look at Bedzed, for example, you'll see passive solar homes developed on a brownfield. Can we build new homes for all 6 billion people this way? No, though I assert that one cannot state that "all the good places are taken" in an all-encompassing sense. Add in existing homes to the mix (as I stated in the letter above), and we can propose methods and materials for the vast majority of homes in the 'developed world" where high primary building energy occurs, though obviously many (or most) won't have the means (or enough sunlight) to achieve passive solar super-insulation status in the near term. And note we haven't provided any plans at this stage.
solar enhancements are only of value when you have reduced your load as much as possible, and THEN you can design your solar enhancements at a commensurate scale.
When planning a renovation, I believe it is wise to examine the entirety first, consider all the design alternatives, then create a plan to move forward by. If one one aspect were considered first, then other aspects like passive solar might require additional rework that might have been unnecessary if it were considered aforehand. I realize that passive solar is not a major energy source where you are in Canada, but it can be for most of the population that heat their homes.
build a frame of wood, and then fix/seal fairly thick plexiglas on both sides, creating a roughly 1 cm space between....Weather stripping tape can then be applied to seal whatever cracks arise.
This sounds like an efficient 'storm window'. The U-value of the air in 1 cm = 0.026 W/(m K)/(0.01m) = 2.6W/(m2 K), so with 10 1m x 2m windows where the inside temperature is 18.3C and the temperature of the inside of the single pane window when the storm window is affixed is -18C, the heat loss reduction from the air space alone is approximately 1.9 kW. The plexiglass will add a little more, and the sealing of infiltration leaks likely much more.
This should make a significant difference compared to your single pane windows. An even greater contribution, depending on how drafty the windows are, is the reduction in infiltration.
Mr Stewart wrote:
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These article series are not simply about building a new passive solar home off out in a greenfield somewhere. All we we have covered so far is the basics, which can be applied to new construction in a greenfield, new construction in a brownfield, and renovation of existing buildings.
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I can accept that.
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Can we build new homes for all 6 billion people this way? No, though I assert that one cannot state that "all the good places are taken" in an all-encompassing sense.
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Nor would it be desireable to house "everyone" that way. I imagine there are any number of traditional peoples who live in grass huts, long houses, yurts, etc. as a way of life, and would find such fixed housing disuseful.
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Add in existing homes to the mix (as I stated in the letter above), and we can propose methods and materials for the vast majority of homes in the 'developed world" where high primary building energy occurs, though obviously many (or most) won't have the means (or enough sunlight) to achieve passive solar super-insulation status in the near term. And note we haven't provided any plans at this stage.
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Reasonable.
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OK
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This sounds like an efficient 'storm window'. The U-value of the air in 1 cm = 0.026 W/(m K)/(0.01m) = 2.6W/(m2 K), so with 10 1m x 2m windows where the inside temperature is 18.3C and the temperature of the inside of the single pane window when the storm window is affixed is -18C, the heat loss reduction from the air space alone is approximately 1.9 kW. The plexiglass will add a little more, and the sealing of infiltration leaks likely much more.
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Well, thank you kindly for doing the math for me! Much appreciated!
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This should make a significant difference compared to your single pane windows.
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Actually, we already have double pane gas filled windows installed by the previous owner - they're just not "good enough" when the temp dumps down to -25C. I don't have an infrared camera, so I've gone around the house putting my palm on the walls and windows, and the windows are Really Cold. Except today - the temp went up to 3C, and I was able to chop some ice out of the walk way... argh.
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An even greater contribution, depending on how drafty the windows are, is the reduction in infiltration.
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Agreed. Once I get the set done, next year I might have something worthy of an article here - a kind of "how to" thing.
best,
S2
A couple of thoughts.
First of all, Fig 2. looks wrong. The overall Passive House standard is 120 kwh/m2-a/15 kwh/m2-a envelope and though some homes in Europe get lower, because of the difficult climate in the US it is unlikely that outside Northern California you could get close to 50kwh/m2-a.
There is an envelope only standard for Passive House residential retrofits of 25 kwh/m2-a which is only slightly easier to meet.
It is a huge concern to the Passive House organization that analysis be done rigorously, preferably by Passive House trained consultants. Hopefully, some people (from TOD..hint..hint) will decide to get PROFESSIONALLY trained; there are quite a few unexpected pitfalls that await the naive superinsulation rehabber and self-described 'experts'(lacking real experience) are everywhere.
http://www.e-colab.org/ecolab/ecolabHome.html
http://www.passivehouse.us/passiveHouse/AboutPHIUS.html
The way things are headed, Obama's energy initiative on the building front will produce
few successes and huge disappointments.
In a way it would be better to concentrate
on increasing energy supply, at least until
a whole generation of architects and contractors have been trained to design buildings correctly.
This country is woefully unprepared to do ANYTHING to meet the energy challenge.
First of all, Fig 2. looks wrong.
This was taken straight from http://www.passivehouse.com/English/PassiveH.HTM. I'll note that this article made no reference to this being energy savings realized in the US.
This country is woefully unprepared to do ANYTHING to meet the energy challenge...In a way it would be better to concentrate on increasing energy supply
I'm extremely surprised to hear a TOD reader and advocate of Passive House say such a thing. Does your organization focus on new construction or are there inexpensive renovation approaches of existing buildings that you can provide an overview of.
Yes, the climate in Germany and even Sweden is much milder than the US where most of the country can see an outdoor +80 degree temperature swing over a year.
Some people think the US should have a separate standard from Passive House; however there is a Passive House school in central Minnesota(BioHaus) which has passed the standard, so in the interests of reducing energy consumption to a bare minimum
it is a practical goal.
http://waldseebiohaus.typepad.com/biohaus/design.html
You can retrofit to Passive House in some cases and there is a standard for that. We want to do that because in some cases there are incentives for rehabbing and disincentives for building new.
The problem with the incremental improvement approach is that a house works together as a system and if concentrate on one aspect, say insulation you can cause condensation and IAQ problems. Plus you quickly get into a problem of diminishing return.
To get a really significant energy cut you can't compromise.
Though I admire and support them, I don't speak for PHIUS. If you are interested in learning how to build the most energy efficient buildings possible, I suggest you become a certified Passive House Consultant so you can advise the screwed up builders and architect how to build energy efficient buildings because they clearly don't know how to.
http://www.passivehouse.us/passiveHouse/PHIUSHome.html
http://www.passivehouse.us/passiveHouse/Articles_files/HEM_Climate_kerna...
http://www.gaccom.org/fileadmin/user_upload/Dokumente/Katrin_Klingenberg...
_Renewables_Roadshow_Chicago.pdf
As far as increasing energy supplies go, I am regularly surprised by TOD readers, who are aware of oil and gas depletion crying about getting off oil but utterly trash the pragmatic Hirsch Report or the Pickens Plan.
If we use the money to build massive wind or new clean coal we will do something that is necessary in the long run.
I love Al Gore but the idea that we will magically eliminate fossil fuels in the next 30 years is cuckoo.
Say no more
Old buildings less energy-efficient? Not always:
http://www.treehugger.com/files/2009/01/economi-_stimulus-sometimes-what...
"The U.S. Energy Information Agency publishes a building energy consumption report every four years, which shows the worst energy performers are buildings constructed between 1959-1989 -- during the first energy crisis! The lowest energy users were generally constructed before 1959, with post-1989 construction coming in a close second."
I'd have to see the report itself to understand the data (I took a look and didn't turn it up). So many older buildings didn't even have wall or ceiling insulation. Before A/C, ceiling fans and open windows (which are appropriate courses of action) may account for some of the energy savings in the pre-1959 set. Changes in multi-unit => single family ratios and larger square footage are likely also factors. We have to be careful to compare apples to apples.
Some of it is obvious on reflection - buildings without aircon will use less energy in the summer, for example.
I would appreciate any insights into the relative merits vs problems of various types of insulation. I haven't seen anything here about metal wool, though elsewhere this has been touted as non-hazardous, pest resistant, not too expensive, versatile, non-flammable, and high-R value.
Any thoughts on this or other materials?
That is not a topic to be answered in a post, but in an article, which would be part of an energy efficiency series.
Thank you for your informative post. Many people, including myself, live in tropical countries. A substantial amount of energy goes into cooling houses and other buildings. Could you please give me a link that would help me with energy efficient ways of cooling?
There will be future articles on building energy efficiency, so I'd rather give the subject sufficient treatment. Stay tuned.