ASHRAE Journal - February 2010 - 60

Learning From Mistakes By Joseph W. Lstiburek, Ph.D., P.Eng., Fellow ASHRAE hose of us who are no longer young remember how easy it was going to be to save energy by caulking and insulating. Stop me if you’ve heard this before. It was anything but easy when we tried this last time.* Not because it was difficult, but because we didn’t know what we were doing. It is amazing to me that most folks no longer remember the 1973 Oil Crisis. In October of that year, Egypt and Syria attacked Israel on Yom Kippur. The Soviet Union got into the act by supplying replacement weapons and supplies to the Arabs. The United States responded by supplying replacement weapons and supplies to Israel. The Arab nations then responded with an embargo on oil exports to the United States. You youngsters can imagine what that did to the price of oil. What made things worse was that we were also in the middle of a stock market crash. It took a decade to recover, and then we were whacked again in 1979 when oil shot through the roof with the fall of the Shah and the Iranian Revolution. The only good news at the time† was that by then Prudhoe Bay and the North Sea had come online so that the second shock was not as bad. Bad is a relative term here as interest rates were at 20% at the time, and the construction industry tanked. You would think that we would have all learned something from the experience. Energy Conservation in Homes T All I can say is that it was an interesting time that proceeded to get even more interesting. A young physicist by the name of Amory Lovins wrote a seminal piece for the journal Foreign Affairs in October 1976 called “Energy Strategy: The Road Not Taken.” It sent policy shock waves through the establishment. Until then, no one had considered energy conservation as a serious strategy. It quickly became a very serious strategy in Canada. We began to insulate every roof in the country and replace oil head. We discovered that buildings, houses in particular, are interrelated systems. In cold climates in the 1970s most houses were constructed with poorly insulated attics. Some attics were vented; some were not. The houses were also leaky by today’s standards. And many of these houses were heated with oil furnaces connected to masonry chimneys. Let’s look at how a poorly insulated attic over a leaky house heated with an oil furnace works. For the time being, let us assume the attic is vented. Air from the outside enters the attic through soffit What happened? How could anyone screw up energy conservation? It was supposed to be easy, a piece of cake, a lead pipe cinch. In retrospect, the obvious happened. furnaces with gas furnaces like there was no tomorrow. The hangover from all this activity hit in the early 80s. Rot and mold joined bad music as the signature symbols for that decade. ‡ What happened? How could anyone screw up energy conservation? It was supposed to be easy, a piece of cake, a lead pipe cinch. In retrospect, the obvious happened. When you change one thing, it changes something else. And when you change that something else, the law of unintended consequences rears its ugly vents located down at the eaves and leaves the attic up high at ridge vents, gable vents or “mushroom” vents. This airflow also mixes with air entering the attic from the house through a leaky ceiling. So, the air entering the attic is a combination of air entering from the outside through the soffit vents and air entering from the inside through a leaky attic ceiling. What leaves the attic at the ridge is a combination of air from the outside (from the soffit vents) and air from the inside (through the leaky ceiling).§ * In Canada we had CHIP (Canadian Home Insulation Program) and COSP (Canadian Oil Substitution Program). It was the 70s, bad hair, bad clothes, but good music. Under CHIP everyone who wanted could get some cash to insulate their attic. Under COSP everyone who wanted could get some cash to replace their oil furnace with a gas furnace. These were huge national programs that were designed to touch every house. The houses we rotted and otherwise screwed up under these programs in the 70s we learned to fix in the 80s. We discovered building science. It resulted in building science moving mainstream and the development of a whole generation of building scientists. † There was also this hockey game played in Lake Placid, N.Y., carried live on Canadian television, but not on U.S. television, where some American college kids beat a team of professionals from the Soviet Union in a round-robin tournament at something called the Olympic Games. ‡ Enjoy the symmetry and irony, Amory Lovins’ energy conservation ideas came north to Canada, the net result of which was building science knowledge moved south to the United States. The movement wasn’t pretty or easy in either direction. I remember as an impressionable idealistic 25-year-old listening to Amory Lovins in the rotunda of the Toronto City Hall thinking that the world was going to change. It did of course, because the world always does, but not in the way that I thought it would. Some things did change but many other things did not change at all. It seems we are asking many of the same questions 30 years later. § Handegord, G.O., G. Giroux. 1984. “An Attic Condensation Model.” Division of Building Research, National Research Council of Canada. Simple, elegant, beautiful. Written down in things called words. But who reads published papers and books and stuff anymore? Especially old stuff with good grammar and logic. ASHRAE Journal ashrae.org February 2010

ASHRAE Journal - February 2010

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