Some of the lessons we learn throughout our professional careers tend to stick better than others. The first time I tracked mud into a customer’s home, I learned the value of shoe covers. It’s a lesson I’ve never forgotten. I had a very similar situation happen with an air-balancing hood and the lessons it taught me many years ago.
I remembered this lesson as I was recently reviewing the National Comfort Institute’s (NCI’s) HVAC System Renovation manual. I came across a page titled “Duct Sizing Myths and Legends.” The first bullet on the list was “A good duct design is self-balancing.” This statement hit close to home for me as it was based on a comment I used to make quite often before the lessons I learned from an air-balancing hood.