In the evaporator, refrigerant evaporates and absorbs heat from air passed over the coil. Heat Exchanger - A device for the transfer of heat energy from the source to the conveying medium. Horizontal Furnace - A furnace that lies on its side, pulling in return air from one side and expelling warm air from the other. Humidifier - A device that injects water vapor into heated air as the air is expelled from the furnace. Humidity - The amount of moisture in the air.
Air conditioners remove moisture for added comfort.
HSPF - Heating Seasonal Performance Factor, a rating used in measuring the heating efficiency of a heat pump. The higher the number, the more efficient the unit. HVAC - Heating, ventilation and air conditioning. ICM - Integrally Controlled Motor. A specially engineered, variable-speed motor .