What should the delta T (ΔT) be? What do you mean!? 20 degrees, of course! We are referring to the air temperature drop across an air handling unit or evaporator coil in cooling mode. Actually, depending on who you ask, the answer will range between 18-22 degrees Fahrenheit. Heck, I’ve heard some insist that […]

This article is written by Sal Hamidi, founder of Productsbypros.com, an innovative manufacturers representative agency that promotes great HVAC/R products through training and media. You can reach Sal at Sal@productsbypros.com.   If we are going to discuss vacuum pump oil, it's important to understand what it is first. Most HVAC application vacuum pumps are rotary […]

If you don’t have a gas furnace or fireplace in your home, your unit’s reversing valve is probably your best friend during the winter months.  As their name suggests, reversing valves reverse the refrigerant flow to send the hot, compressed vapor to the indoor coil instead of the outdoor coil. The system releases heat into […]