A Global Warming Tipping Point, Amplifying Feedbacks, and Building Codes

“Man has lost the capacity to foresee and forestall. He will end by destroying the earth.”

Dr. Albert Schweitzer

“Man’s attitude toward nature is today critically important simply because we have now acquired a fateful power to alter and destroy nature …
but man is a part of nature and this war against nature is inevitably a war against himself.”
Rachel Carson

Many of us in the building professions find ourselves chafing at what sometimes seems to be an unnecessary or arbitrary requirement in our building codes, but the truth of the matter is that our codes represent over a hundred years of priceless “tribal knowledge” focused on keeping us and the built environment safe and healthy. It’s no accident then that our national building codes have also evolved to include requirements for energy efficiency. However, in today’s perspective, the code development and adoption process has three major problems:

1. Codes are reactive and change comes slowly and often only in the face of a serious problem and/or cases of mortality. A child dies and we change the requirements for deck railing. Someone is killed in a fire and we change fire rating requirement for a door or wall. We stand in line to buy gas in the 70’s and suddenly we get religion about insulation. As a result, the codes are especially ineffective for a slow moving crisis like global warming.
2. Codes changes are political. The process itself is public, open, more or less dominated by building code officials, and attempts are made to keep vested interests from unduly influencing the process. However, the actual code development and change process looks and feels a lot like our state and national legislative process with corporations hiring paid consultants and lobbyists in an attempt to add or protect code language that supports their bottom line. In essence, our codes have become the sum of all lobbyists.
3. Local jurisdiction’s are often slow to adopt the latest changes, and may not even bother to adopt the energy code or subject to their own politics, dumb down the codes to cater to local vested interests.

I was in the middle of writing about our building codes when the story broke on a joint study by NASA and Columbia University that concluded that we may be reaching a global warming point of no return, a “tipping point” in as little as ten years. The cause of this acceleration can be observed now in amplifying feedbacks such as disappearing sea ice and melting tundra. According to the report, “these feedbacks all produce more heat, … reinforcing each other, leading to evermore thawing … and more releases of natural greenhouse gases (including CO2 and methane) in a viciously accelerating circle”.

Which brings me back to building codes. Buildings in the U.S. account for over 50% of greenhouse gas emissions, but changing that statistic will require significant changes to codes which evolve very slowly and only respond with any sense of rapidity to a major crisis, not to reports by NASA. I’m sure the response in ten or twenty years from now, when the water is lapping up against the second story windows in Brooklyn will be dramatic, but by then it will be too little, too late and we’ll be too busy building levees and dikes.

So it will take a tangible crisis of the pocket book like a tax on carbon emissions along with tax incentives on the purchase of products and technology that reduce those emissions to create the national sense of urgency required to keep our heads above water. Oh yeah … a little leadership at the national level would help as well. Something on the order of the Apollo Program, Manhattan Project, and WWII Victory Garden campaign combined. Given that we have another two years left with the current administration, that means we’ll only have 8 years to get our act together before NASA’s predicted tipping point.

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Solar PV Costs set to Decline 40%

If you thought PV panels where too expensive, start making room on your roof, because according to latest news from the Worldwatch and Prometheus Institutes, things are about to change.

Global production of solar photovoltaic (PV) cells, which turn sunlight directly into electricity, has risen sixfold since 2000 and grew 41 percent in 2006 alone. Although grid-connected solar capacity still provides less than 1 percent of the world’s electricity, it increased nearly 50 percent in 2006, to 5,000 megawatts, propelled by booming markets in Germany and Japan.

This dramatic growth has actually been constrained by a shortage of manufacturing capacity for purified polysilicon, but that situation will soon be reversed as more than a dozen companies in Europe, China, Japan, and the United States bring on unprecedented new levels of production capacity. In 2006, for the first time, more than half the world’s polysilicon was used to produce solar PV cells. Combined with technology advances, the increase in polysilicon supply is projected to bring costs down by more than 40 percent in the next three years.

The biggest surprise in 2006 was the dramatic growth in PV production in China. Last year, China passed the United States, which first developed modern solar cell technology at Bell Labs in New Jersey in the 1950s, to become the world’s third largest producer of the cells behind Germany and Japan.

China’s leading PV manufacturer, Suntech Power, climbed from the world’s eighth largest producer in 2005 to fourth in 2006. Experts believe that China, with its growing need for energy, large work force, and strong industrial base, could drive dramatic reductions in PV prices in the next few years, helping to make solar competitive with conventional power even without subsidies.

“To say that Chinese PV producers plan to expand production rapidly in the year ahead would be an understatement,” says Travis Bradford, president of the Prometheus Institute. “They have raised billions from international IPOs to build capacity and increase scale with the goal of driving down costs.”

Low-e Glass … A Nation Divided

Low-e glass, first introduced in 1979, has transformed window energy performance. Low-e glass is manufactured with a microscopically thin and transparent layer of metal or metal oxide that reflects infrared “heat” energy back into the home, greatly enhancing the thermal performance of the window.

In the simplest of terms, there are basically two kinds of Low-e glass:

1. Low-e glass with a low Solar Heat Gain Coefficient (SHGC) that also reflects and keeps much of the Sun’s heat energy out of the home. This is the best choice in climates dominated by cooling.
2. Low-e glass with a high Solar Heat Gain Coefficient (SHGC) that allows the Sun’s heat energy into the home. This is the best choice in climates dominated by heating or for south facing windows in climates with a mix of cooling and heating requirements.

All this seems pretty straight forward until you actually attempt to purchase a window with Low-e glass. But before I get into that let’s take a look at the climate zones in the U.S. used by Energy Star to determine the qualification criteria for windows and skylights in an Energy Star rated home.

The Northern zone is the perfect candidate for a Low-e glass with a high SHGC and the North/Central and even the South/Central can greatly benefit from high SHGC Low-e glass on southern exposures. Unfortunately, even though the average American family spends far more on heating than air conditioning, both Energy Star, LEED, and the International Energy Conservation Code (IECC) seem to be color blind when it comes to space heating and the benefits of Low-e glass with a high SHGC.

Energy Star requirements for SHGC seem to be all about cooling as the following requirements for SHGC for each climate zone indicates. The IECC is no better, only requiring a SHGC of ≤ 0.40 for any residence with less than 3,500 Heating Degree Days (HDD). LEED only takes the cooling bias further by requiring even lower SHGC’s in the South/Central and Southern climate zones.

As an unintended consequence of the regulatory bias in favor of cooling, window manufacturers have all but abandoned Low-e glass with high SHGC’s. The result is a nation divided, with more than half of the country left out in the cold without ready access to high performance windows that take advantage of the free solar energy that strikes our windows everyday. With very few exceptions you just cannot find a window manufacturer willing to give you the glass options we need and require in heating dominated climates.

So what’s the consequence of the current regulatory bias? First of all it makes no sense, according to the U.S. Energy Information Administration’s (EIA) 2001 Residential Energy Consumption Survey, Americans consume more than 7 times more energy for space heating than for air conditioning. To get an estimate of what’s on the table for high SHGC, Low-e glass in terms of the potential energy savings I assumed a 10% improvement in heating costs for homes in the U.S. with more than 4,000 Heating Degrees Days. Based on the same 2001 EIA Survey, that would amount to an annual savings of 0.362 quadrillion(1 followed by 15 zeros) Btu’s per year. In monetary terms, that’s about $475 billion dollars worth of natural gas!

When the government gets serious about Global Warming maybe they’ll fix the cooling bias in the regulations, but until then here’s where to go to get a Low-e windows with a high SHGC:

• Accurate Dorwin, Manitoba, Canada
• Alpen Windows, Boulder, CO
• Fibertec Windows, Ontario, Canada
• Thermotech Windows, Ontario, Canada
• INLINE Fiberglass, Ltd., Ontario, Canada
• Marvin Windows & Doors, Warrroad, MN (you will need to call their technical support for architects and design professionals @ 1-800-346-3363 and ask to specify your own glass)

Just want a source for the glass? Try Pilkington North America.

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