COP Coefficient of performance, an efficiency ratio that compares the amount of heat delivered to the amount of energy used. As with MPG on a car, the higher the score themore energy efficient the equipment is.
COMMISSIONING The final step in installing a heating or air conditioning system. Every component is checked and tested for compliance with codes, manuals, manufacturer requirements, and occupant needs. After commissioning, the technician will:provide documentation of testing, provide all equipment manuals, and show thehomeowner how to operate the system.
CONDENSER (HEAT EXCHANGER) The outsideinit of a heating or air conditioning system. Here the refrigerant condenses from a gas to a liquid and hot or cold air from the building is released to the outside.
DUCT Conduits used to carry air. They can be round or rectangular, sheet metal or fiberglass or vinyl tubes. In air conditioning systems they carry air from the home to theair conditioning system or furnace and back to the home.