Our HVAC equipment can’t run without the contactor coil, but contactors can develop problems with age and during high-voltage electrical events. Contact pitting is unmistakable, and it’s unfortunately all too common in areas where bugs can get into the coil and fry on the contacts. Factor in problems with the utility, such as brownouts and […]

Some techs and contractors swear that flex ducts are an evil invention and should never be used in ANY circumstance. I agree with what duct design legend Jack Rise said on the podcast a few years ago when I asked him about flex ducts: “There's a lot of problems with flex duct, there really is, and […]

There is a lot of misunderstanding about the HSO (hard shut-off) or “non-bleed” TXV (thermostat expansion valve) and what makes it shut off, why it exists, and how it “magically” opens. Once you understand the forces inside the valve, it is quite simple, obvious, and sadly devoid of any magic. The Three Forces  The TXV […]

In this podcast, Jeremy Smith joins us to discuss demand cooling in low-temperature applications that use R-22 refrigerant. R-22 is NOT an ideal low-temperature refrigerant because it leads to high compression ratios. The discharge gas also gets really hot and can burn up the oil in the system. (The head of the compressor is even […]

Today, Jeremy Smith joins us to discuss low-ambient conditions and controls, condenser flooding, and headmaster valves. He has also given us a companion article on those subjects, which you can read below. Download the podcast directly HERE. As always, if you have an iPhone, subscribe HERE, and if you have an Android phone, subscribe HERE. […]

Jeremy Smith goes over floating suction and floating head refrigeration strategies. He also talks a bit more about low-ambient equipment operation. Floating suction controls developed when we started using low-pressure controls on rack refrigeration. As the electronics advanced, we developed controls that could control temperature, which impacts pressure as well. Nowadays, controls can cross data […]