Numbers Don't Lie: 71 Things You Need to Know About the World

by Vaclav Smil

That’s a loss reduction of up to 90 percent compared to a single pane. In the world of energy savings, there are no other opportunities of that magnitude applicable on a scale of billions of units. Bonus point: it would actually work. And there is also a comfort factor. With the outdoor temperature at –18°C (common January overnight lows in Edmonton, Alberta, or daily highs in Russia’s Novosibirsk) and the indoor temperature at 21°C, the internal surface temperature of a single-pane window is around 1°C, an older double-pane window will register 11°C, and the best triple-glazed window 18°C. At that temperature, you can sit right next to it. And triple-paned windows have the added advantage of reducing condensation on the interior glass by raising its temperature above the dew point. Such windows are already common in Sweden and Norway, but in Canada (with its low-cost natural gas) they may not be mandated before 2030, and as in many other cold-weather jurisdictions, the required standard is still equivalent to just a double-glazed window with one low-emissivity coating.