2 ms·
> So far, it has been defined by the German standard that limits the heating and cooling load to 4,755 British thermal units per square foot (or 15 kilowatt hou
by elihu 12y ago
> So far, it has been defined by the German standard that limits the heating and cooling load to 4,755 British thermal units per square foot (or 15 kilowatt hours per square meter)—about one-tenth that of homes built to current U.S. codes.
In the comments section, there's a clarification that this is per year. (Kind of a shame to see "unit fail" in a publication that should know better.)
I'm kind of curious to know what sort of new technology (if any) makes high-efficiency targets easier to meet these days. The article talks about triple pane windows and thick walls. Are these stick-frame houses with fiberglass and offset 2x6s in the walls or something like that, or are there new materials? I recently read that aerogel has been coming down in cost to the point where it's plausible that someone with deep pockets might insulate their house with it if they didn't want super thick walls. Insulated concrete forms and autoclaved aerated concrete are also something that some builders use. What else is new?
- danpat 12y agoIt's partly materials, but there are lots of factors: - building codes raising the bar, which has brought down costs for what used to be "fancy" materials - improvements in building science - increased energy costs driving demand for improved efficiency - greater awareness of energy consumption amongst the population I've renovated a few houses build in the 60's and 70's in Canada. As far as I can tell, they had the materials and knowledge to make far more efficient houses, but much of the time, it was just easier, quicker and cheaper to install a big-ol' heater and drive the cold out. With a few simple and relatively cheap building envelope modifications and a more efficient heat source, it wasn't difficult to bring heating costs down by 50% or more.