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…
I used to be a smart-ass who would say things I thought were clever but really were just annoying. When I learned the basics of quantum physics, for example, I had a clever/annoying answer for anyone who asked me, What's…
If a 12 step program is good for helping people deal with addictive behaviors, then a 17 step program ought to be better, right? Or maybe it's just a random number that fits the number of tips that popped into…
Ah, so many choices. If you want to design and install a duct system to create problems, the possibilities are endless. I've certainly written about a lot of them (as well as how to do it properly). Today, though, let's…
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…
What is a hair's breadth? A strand of the finest human hair is about 20 micrometers (also called microns) in diameter. Take a piece and slice it in half. Then take one of those halves and slice it in half…
As we continue our study of indoor air quality and filtration, we now come back to duct design. Today's lesson is on an interesting bit of physics that applies to anything that flows. It could be heat or particles or…