Psychrometrics, you may recall, is the science that involves the properties of moist air and the processes in which the temperature or the water vapor content or both are changed. To understand how all that works, we need quantities and…
I have a confession to make: I've fallen in love with psychrometrics! After water itself, moist air has got to be the most interesting substance in building science. And the psychrometric chart, in all its many manifestations and with its…
Insulation is good. More insulation is better (although at some point, more may not be cost effective). It reduces the amount of heat a home loses in winter or gains in summer. You can get there by building thicker walls…
I'm writing this on St. Patrick's Day so let me tell you a wee bit about the O'Mearas. Kevin and Svetlana O'Meara live in a beautiful home in Utah that's oh-so-close to being a net zero energy home. After I…
Remember those two furnaces I showed you photos of last week? You know, the ones that had ducts placed—or taped, in one case—right in front of them to bring them combustion air. I told you it wasn't a good way…
When I was building a home in 2001, I came across a gazillion little things that I needed guidance on. I'd never built anything larger than a bookcase, so new home construction was quite a big step. I bought books,…
A common misconception about the energy recovery ventilator (ERV) is that it's good for humid climates because it helps to dehumidify a home. It's usually the better choice for a humid climate when you're trying to decide between an ERV…
Energy Vanguard's president, Dr. Allison Bailes, will teach a three-hour workshop called What You Need to Know About HVAC to Work with HVAC Pros at the Mid-Atlantic Sustainability Conference in Harrisonburg, Virginia. Aimed at architects, engineers, builders, raters, and students,…
I've been writing some articles on ventilation for the Journal of Light Construction lately and have come across some great material. The first quote here makes the point about indoor air quality with a graphic underwear metaphor. It's from an…
The small duct in the photo below is supposed to bring in outdoor air for ventilation in this new home. It's a simple method that consists of a duct running from an outdoor wall cap to the return plenum of…