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.

Heat & Heat Measurement

Heat
Heat is a form of energy, primarily created by the transformation of other types of energy into heat energy. For example, mechanical energy turning a wheel causes friction which creates heat.

Heat is often defined as energy in transfer, for it is never content to stand still, but is always moving from a warm body to a colder body. Much of the heat on the Earth is derived from radiation from the sun. A spoon in ice water loses its heat to the water and becomes cold; a spoon in hot coffee absorbs heat from the coffee and becomes warm. But the terms warmer and colder are only comparative. Heat exists at any temperature above absolute zero, even though it may be in extremely small quantities. Absolute zero is the term used by scientists to describe the lowest theoretical temperature possible, the temperature at which no heat exists, which is approximately 460 degrees below zero Fahrenheit. By comparison with this standard, the coldest weather we might ever experience on Earth is much warmer.

Heat Measurement
The measurement of temperature has no relation to the quantity of heat. A match flame may have the same temperature as a bonfire, but obviously the quantity of heat given off is vastly different.

The basic unit of heat measurement used today in the United States is the British Thermal Unit, commonly expressed as a BTU. A BTU is defined as the amount of heat necessary to raise one pound of water one degree Fahrenheit. For example, to raise the temperature of one gallon of water (approximately 8.3 pounds) from 70° F. to 80° F. will require 83 BTU's.

8.3 x (80 70) ---- 83

Katey Werner