Common HVAC Terms

     Air Handler - also called a fan coil depending on installation application, takes the place of an evaporator coil and the variable speed fan from a gas powered furnace. Air handlers extract heat from the air with refrigerant supplied by the air conditioner (or heat pump) in the summer, and reverse the cycle during colder weather, by moving heated air from the heat pump through the home's ductwork. This is the part that is inside the house, usually in the garage, attic or a closet.

     Air Purifier – a Purifier attached to the Air Handler, that captures and kills airborne pathogens such as bacteria, viruses and mold.

     BTU – or British Thermal Unit is the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit.

     Condensate Pump – a specific type of pump used to pump the condensate (water) in an HVAC system.

     Condensing Unit – often called the Air Conditioner or Heat Pump the condensing unit functions as a heat transfer point. The heated refrigerant returned from the evaporator coil (or air handler/fan coil) is sent outside to the air conditioner/heat pump where it is pressurized and sent through the condensing coil. Under high pressure the refrigerant gives up the heat, which is dispelled into the outside air, thus cooling the refrigerant to then be sent back inside to the evaporator coil or air handler to repeat the process.  This is the part that is outside the home.

     Electronic Air Cleaner (EAC) – an electronic device that filters out large particles and contaminants in indoor air. It then electronically pulls out tiny particles that have been magnetized, such as viruses and bacteria, drawing them to a collector

     Evaporator Coil – located in the home and connected to the furnace, the evaporator coil functions as the heat transfer point for cooling indoor air it is comprised of a series of coils filled with refrigerant. As the warm/hot air from the home is returned to the HVAC system it blows through the evaporator coil where the refrigerant filled tubes extract both heat and extra moisture, thus cooling the air. When heating with a heat pump, this processed is reversed to provide heat

     Fan Coil – See Air Handler

     Freon - See Refrigerant

     Heat Pump - an all electric unit that cools like an air conditioner using refrigerant and can also provide heat by reversing the cooling process. Heat pumps extract heat from the air then send the heated refrigerant inside to the coil to heat the indoor air. Heat pumps operate efficiently typically at temperatures of 40° F and above while a gas furnace is more efficient below 40° F.

     Heat Source - a body of air or liquid from which heat is collected. With heat pumps, the air outside the home is used as the heat source during the heating cycle. For geothermal heat pumps (also referred to as ground or water source) heat is removed from the earth or body of water.

     HRU – an acronym for Heat Recovery Unit  that uses the heat from the condenser to keep the water in your water tank warm.

     HSPF - a measure of a heat pump's heating efficiency it is an acronym for Heating Seasonal Performance Factor. The higher the HSPF, the more efficient the product. The government has not established minimum HSPF rating for heat pumps. Carrier’s NEW Greenspeed Intelligence is a revolutionary breakthrough with a 13 HSPF.

     MERV – an acronym for Minimum Efficiency Reporting Value it is the standard comparison of the efficiency of an air filter/air cleaner. The MERV scale ranges from 1 (least efficient) to 16 (most efficient), and measures a filter's ability to remove particles from 3 to 10 microns in size. The size you need will vary based on your individual needs and the static pressure of the duct system.  Higher is NOT always better – as too high a MERV may be restrictive on some duct systems.  Not sure?  Ask one of our technicians. 

     Packaged System - has all of the components of a normal split system completely encased in one unit, a year-round heating and air conditioning system that is located outside the home either on the roof or concrete slab in the yard. Packaged systems can come as cooling only, cooling and gas furnace, heat pump (all electric) or hybrid (electric cooling with dual fuel source heating).

     Puron - see Refrigerant

     Refrigerant – is a chemical that produces a refrigerating effect while expanding and vaporizing. Most residential air conditioning systems contain R-410A or R22 refrigerant. R-22 also known as Freon has been proven to be dangerous to the environment and is being phased out.  R-410A also known as PURON is the replacement refrigerant and the new government mandate for air conditioners and heat pumps.

     SEER – an acronym for Seasonal Energy Efficiency Ratio, SEER is a measure of the amount of energy an air conditioner or heat pump requires to cool a certain space. The higher the SEER, the more efficient the product. The government's established minimum SEER rating for air conditioners manufactured after January 2006 is 13.

     Split System – the most common design for home use, a split system is an air conditioning and heating system with components located both inside (i.e. Air Handler) and outside (i.e. Condenser) the home.

     Supplementary Heat – the emergency or auxiliary heat, usually electric resistance heat, provided at temperatures below a heat pumps balance point.

     UV Lamp (UVC) – UV lamps are mounted in the evaporator coil as an Indoor Air Quality (IAQ) solution an indoor air quality solution. They kill mold as a way of purifying the air and maintaining efficient operation of the coils.

     Zoning – a method of dividing a home into different comfort zones that are individually controlled, depending on the use and need – no more “Why is one room warmer than the other.”