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. […]

Michael Housh from Housh Home Energy in Ohio wrote this tip to help techs determine the air-side charge on a pressure tank. Thanks, Michael! Determining the air-side charge of an expansion tank in a hydronic heating system is a relatively easy task.  A properly sized and charged tank is designed to keep the system pressure […]

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.   When most people think about respiratory devices, their minds probably jump to soldiers wearing gas masks in warfare, hazardous waste […]