Common HVAC Terminology

It can be extremely helpful to have an understanding of basic HVAC terminology, especially if you are looking to upgrade any of your HVAC equipment or you need to speak with a professional HVAC technician about repairs or maintenance. While a high quality professional technician will have no problem explaining everything to you no matter what, knowing the following HVAC terms will make communication much easier:

    • AFUE (Annual Fuel Utilization Efficiency) – The AFUE is the unite of measure used to judge the energy efficiency of a furnace. The higher the AFUE is, the more efficient it is.
    • Air Handler – The air handler is the component in a central air conditioning unit and heat pump that moves heated or cool air through your duct system.
    • Balance Point – The balance point is the outdoor temperature at which the output of your heat pump equals the exact heating needs of your home. This balance point is typically between 30 and 45 degrees Fahrenheit.
    • BTU (British Thermal Unit) – The BTU is the amount of heat that is needed to raise one pound of water by a single degree Fahrenheit.


  • Compressor – The compressor is the pump that circulates an air conditioner or heat pump’s refrigerant in a loop throughout the system.
  • Condensing Unit – Also referred to as the outdoor unit, the condensing unit is the part of the central air conditioning system that is situated outside of the home. It functions as the heat transfer point by collecting heat from outside air as well as dispelling heat to the outdoors.
  • Condenser Coil – The condenser coil is a network of tubes filled with refrigerant. The tubes release a hot refrigerant vapor that condenses into a liquid that absorbs more heat.
  • Evaporator Coil – The evaporator coil is the component within a central air conditioning system or heat pump that is found inside of the home and that acts as the heat transfer point for cooling and warming the air inside.
  • Heat Pump – A heat pump is an air conditioner that can provide your home with both heated and cooled air.
  • Heat Source – A heat source is a body of liquid or air from which heat is collected.
  • HSPF (Heating Seasonal Performance Factor) – The HSPF is the measure of a heat pump’s energy efficiency. The higher the HSPF is, the more efficient it is.
  • SEER (Seasonal Energy Efficiency Ratio) – The SEER is the measure of an air conditioner’s energy efficiency. The higher the SEER rating, the more efficient it is.
  • Single Package – A single package is a heating and air conditioning system that is completely encased in a single unit outdoors.
  • Split System – A split system is an HVAC system in which components are located indoors and outdoors.
  • Supplementary Heat – Supplementary heat is an emergency heating source provided when temperatures drop below the balance point of a heat pump.

Familiarize yourself with these common HVAC terms to make communication with HVAC technicians easier. Be sure to contact us at Woolley Home Solutions for information about our HVAC services today.