For those of you who use the MeasureQuick app for system diagnosis and performance testing, you may have noticed the “fan efficacy” results and wondered what it is. It is simply the CFM output of the system divided by the wattage used by the blower. It is only for the blower motor and has nothing […]

My good friend and contributor to HVAC School, Neil Comparetto, made this video showing how he creates access ports for static pressure and gas combustion analysis. As techs, we find ourselves in the tough position of needing to drill access holes to take measurements, but the drilling and sealing of the holes can sometimes create […]

Let's use a bit of imagination for a minute. Imagine you have two totally identical 3-ton systems. One of them is completely normal, and the other has no fins at all on the evaporator coil. They both have the same charge, airflow, and compressor capacity. What will be different in terms of readings and performance […]