Refrigeration & Air Condition Tech Unit 1

Temperature

A measure of the average energy of motion of the particles of a substance. Or Heat intensity

British Thermal Unit (BTU)

The amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. 1 BTU=1055 joules or 0.293 watt-hours.

Water's boiling point

212�F

Water's freezing point

32�C

Convert Fahrenheit to Celsius

C = 5/9 (F - 32)

Convert Celsius to Fahrenheit

�F = (1.8װC)+32�

Conduction

The direct transfer of heat from one substance to another substance that it is touching. Requires air or water

Convection

the transfer of heat in a fluid through currents. Requires air or water

Forced Convection

The movement of a fluid by a fan or a pump, in order to force heat exchange.

Natural Convection

when warm, less dense fluid is pushed upward as cooler, more dense fluid sinks

Radiation

The transfer of energy through space. The only type of heat transfer that can travel through a vacuum

Sensible Heat

Heat energy that brings about a change in temperature. Occurs in Conduction and Convection.

Latent Heat

Heat absorded or given off when matter changes state

Latent Heat of Vaporization

Quantity of heat absorbed by a substance at which point it changes from a liquid to a vapor.

Latent Heat of Condensation

the energy released when water vapor condenses to liquid water

Latent Heat of Fusion

energy required to change a substance from a solid to a liquid (temp remains constant)

Specific Heat

The amount of energy required to raise the temperature of 1 gram of a substance by 1 degree

Sizing Heat Formulas

Q = Quantity
Q = Weight � Specific Heat � Temperature Difference

Pressure

Force per unit area.
Pounds per square inch (psi)

...

The unit to measure electrical power