My grandfather (yes, the first of this line of 3 Allisons!) was an electrician, plumber, and HVAC contractor, and I had the great fortune of being able to spend a month or two every summer from the time I was…
Every once in a while I like to post some of my favorite pictures of atrocities I've seen in houses, for example the duct stump in the Little Shop of Duct Design Horrors. Today, the subject is HVAC filters, specifically…
Do you know how most HVAC contractors charge for installing HVAC systems, especially in the case of new home construction? By the ton of installed air conditioning capacity. If you've read any of my previous articles about Manual J and…
It's a pretty safe bet that the vast majority of air conditioners are oversized. ACCA developed its Manual J protocol for heating and cooling load calculations to help HVAC contractors put in correctly sized equipment, but there are a couple…
It's been hot and muggy in Atlanta the past few days. Now I'm not your typical Atlantan who says that lightly. I grew up in Houston and south Louisiana and spent nine years in Florida, so I know hot and…
Next month, for about three weeks, professional cyclists will ride 2,200 miles through the hills and towns of France competing for the title of Tour de France Champion. Only one will be crowned champ, but they won't have earned it…
My grandmother was 'cold-natured,' which meant she was more often too cold than too hot. My grandfather could sweat just by thinking about going outside on a summer day in Louisiana (where summer lasts for 5 months). Yet they lived…
A few weeks ago, my uncle, John, called me up and asked if I could design the house where he and his future wife would spend the rest of their lives. Like many people, he wants to save money on…
And now for a little Friday fun, here's one of my favorite duct design failures. I call it Stumpy. What's happened here is that the contractor who retrofitted the duct system just cut this one off mid-run. The problem is…
I know, I know. If you've had a HERS rater class or any education in residential building science, the alarms are going off in your head right now - WAANNNHHHHH WAANNNHHHHH WAANNNHHHHH! Please, let me explain. I know, I know.…