HVACR Glossary
 


Latent heat
A term used to express the heat energy required to change the form of a substance without changing its temperature. The heat energy used to change water to steam, ice to water, water to ice, and to remove moisture from the air is latent heat. It requires 970 Btu to change one pound of water to steam. It also takes 970 Btu to remove one pound of moisture from the air. It cannot be measured by a thermometer. Hidden heat. 1. Fusion - change of state of element or compound from solid to liquid, or reverse. 2. Vaporization - change of state from a liquid to a gas. 3. Sublimation - change of state from a solid to a gas.