Glossary of Marine Refrigeration Terms

British Thermal Unit (Btu): A measure of heat. The amount of heat required to raise one pound of water by one degree Fahrenheit.

Capacity: The amount of heat a refrigeration system can remove in a specified amount of time.

DC Platform: The system used aboard a boat to generate and store DC electrical energy. This includes batteries, alternator, regulator and alternate energy sources such as wind generators and solar cells.

Efficiency: A comparison of the amount of energy expended by an operating refrigeration system to the amount of heat removed.

Eutectic Solution: A solution that maintains a constant temperature while changing state from a solid to a liquid (thawing) or from a liquid to a solid (freezing).

Evaporative System: A refrigeration system that circulates evaporating refrigerant gas to absorb heat directly from the compartment.

Holdover System: A refrigeration system that circulates refrigerant gas by way of tubing inside a tank or cold plate. The refrigerant freezes a solution in the tank that maintains the compartment temperature for extended periods when the system is not running. Maintenance Cycle: The period of time during which the refrigeration system is operating to freeze a cold plate in a holdover system.

Solenoid Valve: A valve, operated by an electromagnetic coil, that is electrically actuated, usually from a remote location.

Amp-hours: Amps are an expression of electrical current flow. To produce an energy consumption figure that represents the amount of current used in a typical day, we use amp-hours, a measurement of current times the number of hours it is being drawn.