A while ago, Bert made a video about his top residential A/C maintenance service tips. He showed some pretty good practices in there, so we’re going to revisit them in this article. Maintenance procedures are vital to any HVAC business, especially those specializing in residential A/C. When we do preventive maintenance, the customers see our […]

Disclaimer: “Ghost voltage” is a term used by techs to explain a phenomenon where they measure voltage they don't expect or when the voltage they see doesn't do the work they expect. More advanced techs know how to use the Lo-Z (low impedance) mode on their voltmeter if it has one to help eliminate this. […]

Old-timers always used to say that running plumbing and condensate drains wasn't rocket science because “water flows downhill.” While that may be true, water also floats in the air, goes uphill, and forces its way through concrete. Here is a look at some of the ways that water moves that impact building comfort and integrity. […]

 In this short podcast episode from AHR Expo 2026, Bryan sits down with John Pastorello for a discussion about the latter's lifetime of HVAC/R. John was a chemist and an HVAC technician before founding Refrigeration Technologies in 1987, and he received the HVAC Tactical Lifetime Achievement Award in 2026. Prior to entering the trade, […]

John Pastorello from Refrigeration Technologies joins us to talk about testing oil and refrigerant for contamination. He also explains what each test is good for. John developed the Checkmate testing kit when he recognized a need to test reclaimed and recycled R-12 for acid and moisture. The Checkmate method removed a small amount of refrigerant […]

John Pastorello from Refrigeration Technologies is back on the podcast to talk about leak detection procedures from start to finish. Big Blu was what started the Refrigeration Technologies empire. John developed Big Blu to create a bubble leak detector with a higher sensitivity to leaks than any other bubble test solution on the market. Big […]