HVAC GLOSSARY OF TERMS

There are common terms and abbreviations used in the HVAC industry which can be confusing for those who aren't familiar with them. Perfect Comfort Inc., a Contractor, has put together a glossary of HVAC terms which may be helpful to those who aren't in the industry.

First, let's start with the term HVAC and HVACR. HVAC is the abbreviation for Heating, Ventilation, and Air Conditioning. HVACR is the abbreviation for Heating, Ventilation, Air Conditioning, and Refrigeration. HVACR professionals are qualified to work on commercial refrigeration systems in addition to heating and air conditioning systems.

Here are some more common HVAC terms you may not be familiar with:

• AC, A/C, or Air Conditioner - An appliance or equipment that modifies the condition of air. Commonly, the term refers to a system that cools air.
• AFUE or Annual Fuel Utilization Efficiency - A measurement that represents the actual average efficiency of combustion equipment like a furnace, boiler, or water heater. For instance, if a gas furnace outputs 90 BTUs of useful heating for every 100 BTUs of natural gas fuel used, the AFUE is 90%. The higher the rating, the more efficient the equipment is.
• AHU or Air Handler - A device which is part of an HVAC system that circulates and regulates air. They generally contain a blower, heating or cooling elements, sound dampers, and filter racks or chambers.
• Blower - Equipment located inside the home that moves air through an HVAC system.
• BTU or British Thermal Unit - The amount of energy needed to increase the temperature of one pound of water by one degree Fahrenheit. However, in the U.S., the term is used to express the power of an HVAC system in BTUs per hour instead of watts. When used as a unit of power for HVAC systems, it is abbreviated as Btu per hour (Btu/h) or just Btu. 1 watt equals approximately 3.41214 Btu/h.
• Compressor - The motor or pump that increases the pressure and temperature of refrigerant liquid so it transforms into a high-pressure gas. The gas then passes to a heat exchanger or condensing coil where it loses the heat energy to the outside air. It then cools and condenses back into liquid form.
• Condenser - The outdoor unit that houses the compressor, condensing coils, and a fan. It is used in central air systems as the heat exchanger.
• EER or Energy Efficiency Ratio - A measurement that represents the energy efficiency of room or window air conditioning systems. The higher the energy efficiency, the more energy you save.
• Evaporator - Large volumes of air are passed through the evaporator coil to remove the heat and humidity in the air.
• FAI or Fresh Air Intake - The opening where outside air is brought into an air conditioning system or boiler room. The air is then treated by the system and distributed throughout the home.
• Heat Pump - A device that moves heat energy from a colder area to a warmer area. Normally, heat energy naturally transfers in the opposite direction, from a warmer area to a cooler area. The heat pump moves it in the opposite direction to effectively heat or cool an indoor climate. It is part of a central air system.
• Return Vents or Return Air Duct - The vent and duct work which removes air from the indoors and recycles it through the heating and air conditioning system.
• SEER or Seasonal Energy Efficiency Ratio - A measurement that represents the seasonal energy efficiency of a central air conditioning system. The higher the figure, the more energy efficient it is.