Glossary Term: Refrigeration & Thermodynamics

Heat exchanger where low-pressure liquid refrigerant absorbs heat from the cargo space and evaporates to vapor, providing cooling effect.

Pressure measured relative to atmospheric pressure. Most pressure gauges read gauge pressure (not absolute pressure).

The total amount of heat that a refrigeration system must remove to maintain desired temperature. Measured in watts (W) or kilowatts (kW).

Heat energy absorbed or released during a phase change (solid to liquid, liquid to gas) without temperature change. For water/ice at 0°C, latent heat of fusion is 334 kJ/kg.

Graphical representation of the physical and thermal properties of moist air, showing relationships between temperature, humidity, enthalpy, and other properties.

Working fluid in a refrigeration system that absorbs heat by evaporating at low temperature/pressure and rejects heat by condensing at high temperature/pressure.

The continuous process by which a refrigeration system removes heat from a low-temperature space and rejects it to a higher-temperature environment.

Heat energy that causes a temperature change in a substance without changing its phase (solid, liquid, or gas).

The amount of energy required to raise the temperature of 1 kg of a substance by 1°C. Measured in kJ/(kg·°C).

Cooling liquid refrigerant below its condensing temperature while maintaining high pressure. Typically 3-10°C of subcooling at condenser outlet.