If you install fiberglass batt insulation* with a kraft paper vapor retarder in a home, which way do you face the vapor retarder? To the inside of the home or the outside of the home? For many building science questions,…
First of all, let's call it what it really is. The industry likes the term "vent-free" when talking about gas fireplaces that keep all the exhaust gases in your home. I prefer the term "ventless" or, even better, "unvented." Not…
Does your heating system have a humidifier attached to it? If so, it's most likely there to treat a symptom while leaving the underlying cause of that symptom alone. The symptom is dry air in winter. Unless you're in an…
One of the things that happens when you learn building science and HVAC design principles is that you can no longer go into any building without looking at the building envelope and mechanical systems. Now that my smart phone doubles…
I've seen it over and over: The central air conditioner's ceiling vents raining down onto the floor. The insulation liner on the duct in the crawl space holding a gallon or two of water. The office that has spots appearing…
Frank Lloyd Wright was a control freak. This was a guy who not only designed houses but also all of the trim details and even the furniture. No, you're right. That's not really enough evidence to convict him. The really…
If there's one building science topic that confuses more people in construction than any other, I think I'd say it's the purposes and properties of the various control layers. I'm talking about the materials that are meant to control the…
I grew up with really bad asthma. Not being able to get enough air into your lungs, in case you haven't experienced it, is pretty scary. I remember lying in bed during one asthma attack, gasping for air, wheezing loudly,…
I was rereading one of Joe Lstiburek's articles last week. The man has a way with words (and I'm not just talking about the four-letter ones). This article was called Understanding Vapor Barriers and is perhaps the clearest, most direct…
If you live in an older house with inefficient, single-pane windows, you may have noticed water condensing on the inside surface of the glass lately. Fall happens to be a pretty good time for that to happen. Do you know…