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. […]

In residential air handler/fan coils, it is common to use a high-voltage interlock between the blower and the electric heat strips to ensure that the blower comes on whenever the heat is on. The problem is that it CANNOT work the other way around where the heat comes on with the blower. Heat strips are […]

As HVAC/R techs, we don't generally do a lot of soldering—unless you are in a shop that has embraced Stay Brite® 8 from Harris. Several aluminum repair products on the market also use an indirect soldering type technique, so this is a general and generic overview of some best practices. As always, follow the manufacturer's […]