Compressibility is the ability of a substance to be squeezed into a smaller volume. It is the change in volume and increase in density that results from an increase in pressure. The subject of compression should be familiar to HVAC techs. After the return air passes over the boiling refrigerant in the evaporator coils, the […]

DISCLAIMER: HVAC School is NOT an official OSHA safety training resource! Although we provide safety tips in good faith, our website is not a substitute for safety training from an authorized OSHA training source.   Let’s be honest: most of us probably got into the HVAC trade because we enjoy working with our hands. Unfortunately, […]

Have you ever noticed that a blower motor rated for 120V draws about twice the amperage of the same horsepower motor rated at 240V? That is because motors are rated in watts or horsepower, and according to Watt's law, Watts = Volts x Amps. To keep the wattage output the same at 120V, it draws […]