PASSIVE HOUSES....I've wondered vaguely for a while why you couldn't build a house that was basically vacuum sealed and thus needed almost nothing in the way of heating and cooling. But it turns out you can, and ground zero for research into "passive houses" is the Passivhaus Institut in Darmstadt, Germany, where I spent a couple of nights just a few months ago. The New York Times reports:
The concept of the passive house, pioneered in this city of 140,000 outside Frankfurt, approaches the challenge from a different angle. Using ultrathick insulation and complex doors and windows, the architect engineers a home encased in an airtight shell, so that barely any heat escapes and barely any cold seeps in. That means a passive house can be warmed not only by the sun, but also by the heat from appliances and even from occupants' bodies.
....Decades ago, attempts at creating sealed solar-heated homes failed, because of stagnant air and mold. But new passive houses use an ingenious central ventilation system. The warm air going out passes side by side with clean, cold air coming in, exchanging heat with 90 percent efficiency.
....In Germany the added construction costs of passive houses are modest and, because of their growing popularity and an ever larger array of attractive off-the-shelf components, are shrinking.
But the sophisticated windows and heat-exchange ventilation systems needed to make passive houses work properly are not readily available in the United States. So the construction of passive houses in the United States, at least initially, is likely to entail a higher price differential.
Interesting stuff. Old news to some, but new to me, and probably new to a few of you as well. More passive houses, please.