An attic that's brought inside the building enclosure is a beautiful thing. This is most often done with spray polyurethane foam (SPF) insulation, either open-cell or closed-cell. Here in the southeastern US, open-cell is most often the spray foam of…
Maybe you've heard the rumblings coming out of the environmental and building science crowd. Maybe not. But it's getting louder lately. The rumbling I'm alluding to is the move to switch from natural gas to electricity as the energy carrier…
The first thing to know about the velocity of air moving through ducts is that the slower you get the air moving, the better it is for air flow. That was the main point of my last article. In fact,…
It's obvious that moving air too quickly through ducts can be a problem. Faster air means more turbulence, more resistance, and more noise. But I run into people who think that low velocity also can be a problem in ducts. …
One of the topics I've hammered on for years is the inadequacy of using rules of thumb for sizing air conditioners. The standard one ton of air conditioning capacity for each 400 to 600 square feet of conditioned floor area…
Last August I began a series of articles on filtration and indoor air quality. You can find the list of them at the bottom of this article but let's do a quick review here: We spend a lot of our…
So we've looked at a simple way to estimate the heat pump balance point. If you also read the comments of that article, you should be aware that there's more to the actual balance point than what I wrote in…
Since more people are using heat pumps these days, even in cold climates, let's spell out the three different types of heat that conventional heat pumps provide. Why not! We've just recently covered the three main sources of home heating…
Earlier this week I wrote about the three main sources of heat in homes. At the end of the article I threw in a fourth one, solar energy, but then I dismissed it as something that people tried in the…
Over the past few months, I've taken a look at some critical issues for indoor air quality. Starting with the issue of how much time we spend indoors, I then wrote about kitchen ventilation, the panoply of indoor air pollutants,…