Air Conditioning: How It Works - Glossary
Air conditioner: A mechanical device used to control temperature and air movement in a confined space.
Btu/h (British Thermal Units per Hour): A measure of cooling or heating capacity.
Capacity or Load: A refrigeration rating system usually measured in Btu/h.
Compressor: A refrigeration or air-conditioning system pump that circulates refrigerant through pipes between an outdoor and indoor unit using pressure.
External Static Pressure (ESP): The measure of static pressure losses from ductwork, fittings, dampers, grilles, and any other devices located in the airstream. ESP listed in the equipment specification charts is the amount of external static loss that the unit lower can overcome at a specific CFM.
Heat pump: An air-conditioning system can reverse the direction of refrigerant flow to provide either cooling or heating to the indoor space.
HSPF (Heating Season Performance Factor): A rating of the seasonal efficiency of a heat pump unit when operating in the heating mode.
HVAC: A term which stands for Heating, Ventilation, and Air Conditioning.
Indoor unit: The air handler of an air-conditioning system, which contains a heat exchange coil, filters, remote signal receiver and fan and provides conditioned air into the space.
INVERTER Technology: Mitsubishi Electric's MUY, MUZ, MXZ and all P-Series outdoor units use INVERTER-driven compressor technology (Variable Frequency Drive) to provide exceptional indoor cooling and heating. By responding to indoor and outdoor temperature changes, these systems reduce power consumption by varying the compressor speed to meet load requirements providing for extra energy savings. The system operates only at the levels needed to maintain a constant and comfortable indoor environment. Our CITY MULTI® product line also incorporates INVERTER technology.
Microprocessor: An electrical component consisting of integrated circuits, which may accept, store, control, and output information.
Outdoor Unit: A component of an air-conditioning system which contains compressor, propeller fan, circuit board, and heat exchange coil. It pumps refrigerant to/from indoor unit.
Refrigerant: A gas/liquid substance used to provide cooling by direct absorption of heat. Mitsubishi Electric products use environmentally-friendly R410A refrigerant.
Refrigerant lines: Insulated copper tubing through which refrigerant flows to and from indoor and outdoor units.
SEER (Seasonal Energy Efficiency Ratio): A rating of the seasonal efficiency of air-conditioning or heating units in cooling mode.
Split-Ductless System: A system comprised of a remote outdoor condensing unit connected by refrigerant pipes to a matching, non-ducted indoor air handler and a remote controller. Special cases for introducing ventilated air may call for limited ducting to air handler from outside.
Split-Ducted System: A system comprised of a remote outdoor condensing unit connected by refrigerant pipes to a matching, ducted indoor air handler with minimal field installed ductwork and a wired remote controller.
Split-zoning System: A system comprised of a remote outdoor condensing unit connected by refrigerant pipes to a matching, indoor air handler that conditions single or multiple room space that is conditioned to a set temperature and is independent from other rooms within the same structure.
Zone (zoning): A single or multiple room space that is conditioned to a set temperature and is independent from other rooms within the same structure.