Crawl Space Noodling: Facing Your Fears
I taught Manuel about sealing the holes in air barriers, ducts, and crawl spaces. He taught me how to face my fears by sticking my arm into holes in the ground. Manuel was my best worker when I did home…
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Air Sealing an Attic Access the Right Way
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…
Get Ready for the 2022 National Home Performance Conference!
One of my absolute favorite conferences is coming up soon. The Building Performance Association* is holding its annual National Home Performance Conference next month in Nashville, Tennessee. When I was new in the world of building science and home performance,…
R-Value vs. Thermal Resistance
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…
Will a Heat Pump Water Heater Freeze Your Basement?
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…
Frost in the Attic Has an Obvious Cause
If you've ever seen frost in the attic in winter, it's pretty to easy to understand why it's happening. It's the same thing that causes morning dew on the grass, frost on the exposed half of my car, or water…
The Central vs Dedicated Return Vent Debate
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…
What Is a Mini-Split Heat Pump?
Ah, mini-splits. They’re all the rage in the world of high-performance HVAC. But what exactly is a mini-split heat pump? Unfortunately, the terminology around this technology is confusing because it’s used so inconsistently. Let’s start at the beginning. (Well, OK,…
Which Roof Penetrations Cause Water Damage?
Which roof penetrations cause water damage? They all do, of course. But some are more likely to leak than others. The photo above shows the back of my house. We got a tiny bit of snow on Sunday, and some…
Roof Overhangs and Moisture Problems
Roof overhangs and moisture problems in the walls of a house ought to be related, right? After all, most of the water that lands on a house hits the roof first. From there, rainwater runs to the bottom edge of…