Wednesday, July 30, 2008

Free Means You Don't Have to Pay

By Dan Morrison

My home state of Connecticut has figured out that the projected budget surplus, which became a projected budget deficit, will actually be a surplus again. That’s pretty good news. Maybe it went from projected deficit back to surplus because they cut a few million here and there after the initial surplus projection was scaled back. And I suppose, that’s the fiscally responsible thing to do: when it looks like my paycheck will be a little short for the month, I don’t generally whip out a credit card, I look for places to cut back. Working from home is my favorite option, but sometimes the wine and beer budget just has to take a hit.

A rainy day fund looking for an umbrella
Now that Connecticut has a little extra cash, they’re (we’re?) looking for ways to spend it. Naturally, the folks who got trimmed want some of their money back. This seems fairly reasonable. One thing that the legislature and Governor are talking about is home heating aid for low income families. They want to give folks money to buy heating oil (or gas, or electricity) this winter because the price of energy is so high and Connecticut gets cold in the winter. On the surface, this sounds like another reasonable idea -- poor folks ought to be able to keep from freezing. But what it really amounts to is a big subsidy for big oil companies -- “Raise your prices all you want, the government will foot the bill so that people continue to pump oil into the side of their houses.”

A radical idea: use less oil and gas
CT spent over $24 million last year on energy assistance (more than $13 million came from the Federal Government) Will it happen again next year? Yes. Is it likely to happen indefinitely? It’s a good bet. $24 mil is quite an annual gift to the oil and gas companies (The Feds donated $450 million last year). We’re spending millions of dollars every year on energy Band-Aids. By spending money once on home energy audits, air sealing, duct sealing, and insulating, we could cut the energy use in CT homes by a bunch -- 40% isn’t unreasonable at all. It would reduce our dependence on foreign oil, put money in people’s pockets (or rather stop pulling it out), lower air pollution, decrease oil spills (did you hear about the 400,000 gallon oil spill near New Orleans last week?) and create green jobs to boot. Everyone’s a winner. Well, almost everyone.

If we’re going to dig our way out of the energy mess we’re in, we need to look long term and weigh options honestly. Home energy assistance programs may help families in the short term, but they keep families, states, and our country (Land of the Free) shackled to big energy bills in the long term.

Free means you don’t have to pay.

--Dan Morrison is managing editor of GreenBuildingAdvisor.com

Monday, July 28, 2008

Do Window Shades Save Energy?

By Peter Yost

While theoretically impossible to actually "save" energy, interior window shades can indeed keep summer heat out and winter heat in. The real question then becomes How well do they perform, and under what circumstances?

In the summer, shades keep out heat, but also light
Interior shades can reflect back out light energy that would otherwise be converted to heat energy. According to the authors of the best resource on the topic, Residential Windows (Carmody, Selkowitz, Arasteh, and Heschong), “drapes can reduce the solar heat gain coefficient of clear glass from 20 to 70 per cent.” That's a pretty big range -- how well they exclude heat depends on the shade's color (silver would be the best, black would be worst), and their proper use. They can’t block anything if they are not closed, and when they are closed, you of course can’t see anything out the window, and you need to turn on a light inside (so, Laws of Thermodynamics notwithstanding, are they really saving energy?).

Exterior shading, on the other hand, performs better all around: it can deflect 100% of the direct solar gain, does not depend on occupant operation, and does not eliminate views. So, interior shades do work to reduce direct solar heat gain, they just do it rather poorly in the grand scheme of things.

In the winter, shades let reduce radiant heat "loss"
You will see claims of up to R-8 by some manufacturers of interior shades in terms of reducing heat loss. Just as with insulation in a wall cavity, the insulating value of a window shade depends on a continuous air barrier being right next to it. How many of these interior thermal shades have an airtight seal around their perimeter? None that I have seen; instead, convective currents short circuit their thermal performance. It is hard to say just exactly what their performance is, because there is no standardized third-party testing of window shades, as there is for windows. But be happy with a couple or so “R”s, not R-8. And once again, you have to operate the shades to get their best performance. Leave them down or closed on a day that turns sunny, and you have a net loss of energy. Open or up at night—oops.

Interior shades can make rooms more comfortable; they have been shown to boost thermal comfort (raise the mean radiant temperature) by as much as 5°F. But just as with overall energy efficiency, improvements in thermal comfort with interior shades depend on how well the windows work to begin with. Improvements are highest and most noticeable with older, poorly performing windows. That bears repeating: Improvements are highest and most noticeable with older, poorly performing windows. Or put another way, good windows work better than shades.

So, interior shades can keep your house cooler in the summer (during the day) and warmer in the winter (at night). But for real energy savings and overall performance, go with high performance windows and exterior shading, and relegate interior shading to handling privacy. After all, you put these “holes” in your walls for the views and the free light!

--Peter Yost is Director of Residential Services at BuildingGreen

Thursday, July 24, 2008

Why Do You Build Green?

Last May I asked builders, designers, and other folks at NAHB's National Green Building Conference why they build green. Here's what they said:


More to come after West Coast Green and GreenBuild...

--Dan Morrison is managing editor of GreenBuildingAdvisor.com

Are Heat Pumps Green?

By Dan Morrison

An article in the Home and Garden section of the New York Times "Time to Worry About Heat Bills" By JAY ROMANO (http://www.nytimes.com/2008/07/24/garden/24fix.html?emc=tnt&tntemail1=y) talks about a winter heating option that will save you money: electric heat pumps. With the price of gas and oil skyrocketing, the article reasons, an electric heat pump will be a money saver this winter and eventually end up "paying for itself."

But is it green?
Not if you're getting your electricity from the grid.
  • Coal plants have an efficiency of about 31%; put another way, almost 70% of the energy contained in a lump of coal is lost as heat when it's burned at a coal plant.
  • And along with that heat, tons of carbon dioxide are dumped into the atmosphere when the lump of coal is burned.
  • And strip mining for lumps of coal leaves a mighty big footprint on the land.

I sure wish I could convince Henry Gifford to let me publish his manuscript on why heat pumps are not such a great idea.

--Dan Morrison is managing editor of GreenBuildingAdvisor.com

Thursday, July 17, 2008

What’s wrong with this picture?

















a) The rim joist is too heavily notched.
b) Using framing cavities as duct runs frowned upon by codes and professional associations.
c) This passed the framing inspection.
d) All of the above.

The answer is d, all of the above.

While it appears that this rim joist isn’t structural (there are studs below it), The Engineered Wood Association says that when cutting multiple holes in a rim joist, the spacing between the holes should be at least twice the length of the longest side of the longest rectangular hole. And according to Joe Lstiburek, the photographer, this also passed the framing inspection.

This leaves option b, “Using framing cavities as duct runs is a bad idea”. This photo shows both stud and joist cavities being used as return air ducts. In their duct design guide Manual D, the Air Conditioning Contractors of America (ACCA) recommend not using panned joists for return ducts, and the 2006 IRC and IECC codes prohibit joist cavities for supply ducts. It’s too bad that neither does both.

Framing cavities make bad duct runs because the leak and they’re connected to every part of the house via framing gaps and holes for wire and pipe. These leaks suck in air from unintended sources (outdoors, attics, garages, and crawlspaces). Along with this unintended air comes humidity, mold, dust, and whatever else is in these spaces (radon, carbon monoxide, gasoline, paint thinner, pesticides,). Not only does this poison the indoor air supply, but it increases the heating and cooling loads while decreasing the efficiency of the mechanical equipment. A bad idea all the way around.

— Bruce Harley is technical director of Conservation Services Group and author of Insulate and Weatherize (Taunton 2002). Photo by Joseph Lstiburek

Got a dumb building picture? Send it to dan [at] buildinggreen.com

Tuesday, July 8, 2008

Green Products Don’t Make It Green

By Matt Golden
A green house can be built with un-green products and an un-green house can be built with all green products. Its about process first, then products.

In our common vernacular, “green” has come to mean many things, and at the same time nothing at all. It has become the de-facto term for environmentally sound – dealing with everything from healthy living to energy consumption and global warming. Clever marketing has people choosing hair products and hybrid cars based on their green status.

Greenwashing 101
By watering down the term to mean expensive products, we promote the idea that we can buy our way to greenness without delivering real solutions to the environmental issues we face. This is greenwashing folks, and it has a very real potential to derail the positive effect of the green sector. We run the risk of alienating consumers as they become jaded by marketing claims that don’t represent reality.

When we really analyze the choices and products being offered by the green industry, it seems that we are starting at the wrong end of the spectrum. Almost everything that is fed to consumers turns out to be the most expensive and often the least effective measures.
Installing solar electric panels on a house will cut the coal we burn and lower the electric bill, but it’s not the best place to spend your money first. We’ve been building bigger, more power hungry homes for years; do we really think the answer lies in yet another big purchase?

What matters are results, not products
If we really want to reduce pollution, stop global warming, and minimize our dependence on fossil fuels, we need to be honest and clear about how we’re dealing with consumers’ wants and needs, and frame “green” by results.

Housing is a great place to start. There are more than 125 million existing homes in the United States. According to the US Energy Information Administration, these buildings represent 21% of the total US carbon footprint. Clearly, we can have an immediate environmental impact by improving the efficiency of these existing homes. Solar panels, hybrid cars, tankless water heaters, bamboo floors, and no-voc paints are great products, but when you approach a building as a system, you realize that individual products, no matter how high tech, can not replace proper fundamentals like tight duct work, good insulation, and weather stripping. By making smart improvements and working with the basics (which are often less expensive) we can make houses work properly so that they become healthy, comfortable and efficient – at a fraction of the cost.

We need to focus on solutions to people’s problems, whether it is energy costs or allergies. Once we have identified the core of each problem, we can address the real world issues and make a real difference when it comes to reducing the carbon footprint.

Tips to avoid greenwashing
As we in the green building world market our services and solutions, there are some clear guidelines we can follow to ensure we are not engaging in greenwashing.
Get the big picture - Understand all of the environmental impacts of your product across its entire lifecycle and share that information with your customers.
Be honest - Don’t overemphasize benefits to hide shortcomings.
Walk the talk - Keep improving your environmental footprint, and encourage your customers to join you on that journey.
Prove your point - Draw on respected standards and certification programs for legitimacy of environmental claims.

We are not lacking the technology to get the job done. The solution lies in helping consumers make smart choices, and thinking in terms of entire systems not simply the latest products.

Related article: The Six Sins of Greenwashing

--Matt Golden owns Sustainable Spaces in San Francisco, Calif