Attic access points can be a mind-blowing thermal liability. If you don't believe me, open the pulldown stairs or scuttle hole and go into an attic on a cold day. Then turn around and look down through the hole. You'll…
I've been known to argue for using building science terms correctly. I've written articles about how we shouldn't use the word "breathe" in relation to houses and that air doesn't have any capacity for holding water vapor. I've even written…
Are you considering replacing your current water heater with a heat pump water heater but worried that it'll freeze your basement in winter? Well, enough homes have this new technology that we now have some data on this topic. A…
The central vs dedicated return vent debate has a clear winner. But first, let me explain the terminology. A forced-air heating and cooling system has supply ducts that blow conditioned air into the rooms of your house. That's the part…
The two primary ways you can heat your house are by burning a fuel (e.g., fossil gas, fuel oil, wood) or using electricity. Furnaces and boilers distribute the heat from combustion to heat a house. Electric resistance heat makes sense…
Oh, how the news media love the “thermostat wars” between men and women. It’s a good source of stories based on conventional wisdom and the occasional (faulty or incomplete) research paper. The utility companies want in on the action, too.…
It was two years ago this week we had the nasty old fossil gas natural draft water heater removed. (That's it in the photo below.) Outside of running a gasoline powered generator inside a house, this kind of water heater…
I recently finished writing the chapter on the interaction of structure and control layers in my book. The last part was on the various ways to insulate the top of a house. The most common, of course, is to have…
The purpose of my Building Science Term of the Week feature is to provide a basic definition of a term you may have heard without going into all the whys and wherefores. Last week I probably went a little overboard…
At first glance, the word “flux” looks like it may not be appropriate in polite company. In fact, though, it’s a word used in physics all the time. Flux comes from the same Latin root that gives us “flow.” The…