Nova Kool Manufacturing ULC

Basic Refrigeration Principles

Most users normally associate refrigeration with cold and cooling, yet the practice of refrigeration engineering deals almost entirely with the transfer of heat. This seeming paradox is one of the most fundamental concepts that must be grasped to understand the workings of a refrigeration system.

Cold is really only the absence of heat, just as darkness is the absence of light, and dryness is the absence of moisture.

Sensible Heat

Sensible heat is defined as the heat involved in a change of temperature of a substance. When the temperature of water is raised from 32 F. to 212 F., an increase in sensible heat content is taking place. The BTU's required to raise the temperature of one pound of a substance 1° F. is termed its specific heat. By definition the specific heat of water is 1.0, but the amount of heat required to raise the temperature of different substances through a given temperature range will vary. It requires only .64 BTU to raise the temperature of one pound of butter 1 degree F., and only .22 BTU is required to raise the temperature of one pound of aluminum 1 degree F. Therefore the specific heats of these two substances are .64 and .22 respectively.

Katey Werner