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…
Back in my home performance contracting days (2004 to 2007), I spent a lot of time in unconditioned attics and crawl spaces. First, I was there to find problems. Then, if the homeowners hired me, I'd go in and do…
It's time to revisit one of my favorite topics: the powered attic ventilator. Ten years ago I wrote an article titled Don’t Let Your Attic Suck - Powered Attic Ventilators Are a Bad Idea. It's got 169 comments and would…
Poor installation of insulation matters. Even in cases where you might think the R-value won't be affected, it is. Eleven years ago this month, I wrote an article about one of the most important and misunderstood principles in building science. …
A lot of people have gotten the message that ducts for your HVAC system—and the system itself—should be in conditioned space. Researchers at the National Renewable Energy Lab (NREL) studied the effect of ducts in an unconditioned attic and found…
Sizing a heating or cooling system should start with an assessment of the heating or cooling load. Nowadays, we know the physics behind heat transfer, so we can come up with fairly accurate predictions of how much heating and cooling…
Using the wisdom of Cool Hand Luke to explain building enclosures, mechanical systems, or indoor air quality is a long established tradition in building science. Joe Lstiburek's Cool Hand Luke Meets Attics is the pinnacle of this genre, of course,…
Yesterday I did a consultation with a homeowner in Michigan. He's got a 60 year old house with a boiler and radiant heating system that has become a burden. The pipes for hydronic distribution system just developed their seventh leak…