Evaporator temperatures below 32° are common and acceptable in refrigeration; that's why there is a defrost sequence. In a heat pump running in heat mode, it's the same; freezing is a part of the process, and defrost is necessary. In comfort cooling, we can't allow the evaporator to get below 32°, or it will freeze. […]

Imagine, if you will, a 20-year-old kid. He has no formal training in the HVAC/R field, only ride along “training” and book learning as he reads along with his journeyman father with whom he's riding. One stormy summer evening, a service call comes in for an ice cream freezer down. After calling and talking to […]

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, […]