Refrigeration Terms and Definitions
Learn refrigeration and HVAC terms and definitions as they relate to the grocery industry.
A system that uses changes in pressure to reactivate an absorbent media bed. Usually used with two beds in parallel (one regenerating, one active). Frequently used in gas purification or drying.
A psychrometric chart is a chart and industry-standard tool that is used to visualize the interrelationships between dry air, moisture, and energy.
Psychrometry is the study of the thermodynamic properties of mixtures of air and water vapor.
A ratio of the actual absolute humidity to the saturation humidity at the current temperature and pressure, usually given as a percentage. Because the saturation point of air changes with temperature and pressure, RH changes with both.
A roof top unit (RTU) is a roof-mounted HVAC enclosure that usually includes a distribution fan, heating and cooling coils, and other air handling equipment.
A unit of pressure that represents Earth’s average atmospheric pressure at MSL.
A unit of fluid flow (typically a compressible gas) representing the mass of gas flowing past a reference point normalized to standard temperature and pressure (STP), or the mass flow rate. The actual volume of a compressible gas will vary with temperature and pressure.
Unit of heat energy frequently used in terms of natural gas. Equal to 100,000 BTU. Typically the average heat energy contianed in 100 cubic feet (1 CCF) of natural gas.
A millimeter of mercury is a unit of pressure equal to that which is generated by a column of mercury one millimeter high. One Standard Atmosphere is about 760 mmHG.
A mechanical device that increases the pressure of a working fluid.