I am like most contractors and techs. I've heard about HEPA for a long time, but I never looked into how it could be integrated into an A/C IAQ strategy until now. First, here's what HEPA is: HEPA (High-Efficiency Particle Arrestance) is an ASME, U.S. DOE standard that specifies a capture rate of 99.97% of […]

It’s that time of year again—the furnace service calls are peaking. It’s a good idea to crack open Jason Obrzut’s book, Gas Heating: Furnaces, Boilers, Controls, Components, and listen to the many public podcasts and presentations by experts like Jim Bergmann. At HVAC School, we’re fortunate to have had some of the industry’s greatest minds […]

When I first started in the trade, we used to run into shielded control wires on the Carrier Comfort Zone 1 zoning systems and also on a Carrier VVT system I used to maintain at a bank. I knew it has something to do with electrical “noise” and that communicating systems often called for it, […]