There is a big move in residential and light commercial HVAC toward measuring static pressure regularly during commissioning, service, and maintenance. Don't get me wrong… Measuring static pressure is VERY important. The challenge comes in when techs begin taking measurements without understanding where to take them, what they mean, or worse: they use measurements as […]

There are many examples of teaching using metaphors to help someone grasp how something works without being EXACTLY correct. Some examples are how we often use water flow to explain electrical flow or refrigerant circuit dynamics. It's enough like the way it works to get our heads wrapped around it, but there are many differences. […]

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. […]