Over the last 30 years, there has been a big move away from conventionally framed roof structures towards engineered structures— specifically engineered trusses and load-bearing engineered beams like micro laminated and even steel. I have been in so many attics where the engineered roofing or other load-bearing structures have been cut to accommodate equipment, wires, […]

  Flowing nitrogen while brazing and pressurizing with nitrogen are great practices. Putting nitrogen in with the refrigerant? Not so much. Nitrogen is a “non-condensable” gas because it cannot be condensed (under normal conditions). However, nitrogen is just one of the non-condensables. First, let's talk about what a non-condensable gas is. Any gas that does […]

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 […]