While you may be familiar with the term HVAC or Heating, Ventilation and Air Conditioning, there are other terms associated with HVAC that can leave many consumers feeling a little overwhelmed. Whether you’re shopping for a new system or want to better understand what your HVAC technician is talking about, here are just some of the terminology you should be aware of.
Efficiency Terms
Back in 1992, the Federal Government created minimum efficiency requirements for heating and air conditioning systems and equipment. It is important to understand efficiency ratings as it could help you to achieve significant energy savings. Some of the terms you should know include:
AFUE: This is a measure of the furnace efficiency and stands for the Annual Fuel Utilization Efficiency. The current minimum standard is 78%, but in simple terms the higher the AFUE rating, the more efficient the furnace.
SEER: The Seasonal Energy Efficiency Ratio is a measurement of air conditioning cooling efficiency. The established government minimum rating is 10, but again the higher the rating, the greater the efficiency.
HSPF: Heating Seasonal Performance Factor is a measure of the heat pump efficiency. There are no current legislated rating minimums, but the higher the rating, the more efficient the heat pump.
Basic HVAC Terms
If you feel like your HVAC technician is speaking a different language when they’re explaining maintenance or repair issues, you need an understanding of some of these basic HVAC terms.
Air Handler: This is the component of your heat pump or AC system that moves the conditioned air through your ductwork.
Coil: Most central air systems feature an indoor and outdoor coil. The indoor coil functions as a heat transfer point, while the outdoor coil or condenser is used to dispel heat outside.
Single Package: This is a year round heating and AC system that has all its components encased in one unit. This type of system is mostly used in commercial or rooftop applications.
Supplementary Heat: This is the emergency or auxiliary heat provided when temperatures reach below the balance point of the heat pump. This is typically electrical resistance heating, but it can also be oil or gas fired equipment.
Technical HVAC Terms
Defrost Mode: Frost can accumulate on outdoor coils during a heat pump heating cycle. To maintain efficiency and remove this frost, the system automatically defrosts itself. This usually takes only a few minutes before the system switches back to heating. During this mode, it is normal to see some steam rising from the outdoor unit.
COP (Coefficient of Performance): This is a ratio that is calculated by dividing the heat pump total heating capacity by the total electrical input x 3.412.
EER (Energy Efficiency Ratio): This is calculated by dividing the BTU cooling capacity by the power input.
Ton: Air conditioners and heat pumps are usually sized in tons. A ton is equal to 12,000 Btu/h, and a typical single family home is between 2 and 5 tons. This is not a constant capacity, and the actual capacity will change based on the indoor and outdoor temperatures. The rating on specific products is based on the equipment performance at ARI standard temperatures of 80ºf inside and 95ºf outside.