Building science is an odd subject. Few colleges and universities teach it. The majority of those who work on buildings call themselves engineers, architects, and contractors, not building scientists. And many of those who do invoke the term can explain…
We live in this invisible stuff called air. (But of course you knew that.) We pump it into and out of our lungs. We exhaust it from our bathrooms and kitchens. We cycle it through our heating and air conditioning…
I was on a tour of passive house projects in Seattle a couple of days ago when someone asked me, "What do you call the outdoor part of a heat pump? The condenser? The compressor?" For someone not immersed in…
What if a builder refused to build from plans drawn by an architect? What if a tile installer refused to implement designs handed to them and instead did their own thing? What if an HVAC contractor told a potential client…
It's cooled off a bit here in Atlanta. A couple of weeks ago we even had temperatures down in the low 50s Fahrenheit. Ah, that felt nice, especially since I've been running again this year.1 With the fall equinox two…
We've had some beautiful, cool weather here in Atlanta the past couple of days. It's about 50° F outdoors as I write this. The high yesterday was only about 70° F. We're getting a few more heating degree days (HDD)…
You can tell how energy efficient a furnace is by its official efficiency rating, the Annual Fuel Utilization Efficiency (AFUE). It's a measure of how much of the heat originally in the fuel that's being burned is available for delivery…
Here's a little conundrum for you. To get the right amount of heating and cooling to each room in your home, you need a load calculation. Rules of thumb don't work. But if you do a load calculation, the result…
When it's hot out, we want cold. At night, we like to be able to turn on the lights. During the daytime, it can be hard to find the darkness. All these things — hot and cold, light and dark,…
Three weeks ago, I wrote about an attic with spray foam insulation and the interesting humidity pattern we observed in it. We placed data loggers near the ridge and floor of the attic as well as in the living space…