Disconnects walk the fine line of being HVAC or electrical, but the HVAC technician is allowed to repair and replace disconnects in most places. Even if you work at a place where it isn't allowed, finding problems is a diagnostic skill you will want to have. As always, work safely with proper safety gear and […]

The amount of pressure you're under depends on where you live. I live in Florida, so I'm very close to sea level. Therefore, the weight of the atmosphere is exerting exactly 14.7 pounds per square inch (PSIA) of pressure on every surface in every direction. There is no such thing as negative pressure—only pressure lower […]

If you work in refrigeration, you may have heard the term “hot pull down.” This phrase describes a condition where the load on the evaporator is above design due to the box temperature or the temperature of the product in the box being higher than it would normally be. My grandpa called me a few […]