If you are used to simple, straight cool split systems, you know that the low voltage to the outdoor unit is usually VERY simple with just a Y (contactor power) and a C (common) connected to the outdoor unit in many cases. When the condensing unit controls are strictly two-wire low voltage, there is no […]

I heard a great presentation by Ron Auvil on VAV systems, and it got me thinking… Can you size a commercial system/perform a block load by the number of occupants? Yes!  No, I'm just kidding. That's crazy talk. There is way more to it than that. However, in a commercial environment, while the building's perimeter […]

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 […]