Photo Courtesy of Parker/Sporlan There are many brands and styles of evaporator pressure regulating valves (EPR), but none as common as the Parker/Sporlan SORIT and ORIT valves. The diagram above clearly shows some of the common applications. An EPR or “hold back” valve maintains a set suction line pressure and, therefore, coil temperature. That is […]

This article was written by HVAC contractor and Building Science Whiz, Michael Housh. Thanks, Michael! For a while, I’ve fallen into this camp where I feel Manual J overshoots heating loads. First off, I would like to say that Manual J is only as good as the information you give it, but we often run […]

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 […]