The Rosetta Stone: HVAC Edition – 11 HVAC Terms Every Homeowner Should Know

Owning your own home is an incredible feat, and an equally impressive undertaking. We live in an age where there is almost always a service professional, or even an app, to meet your household needs. However, interacting with a service professional can often feel like trying to break down a language barrier, and HVAC is not immune to this technical jargon.

Here are 11 terms to have in your arsenal when your HVAC technician is throwing out acronyms more foreign than your kids’ texting lingo:
1) AFUE: (Annual Fuel Utilization Efficiency) This is a rating of how efficiently a gas furnace converts fuel to energy. For example, a rating of 90 indicates that 90% of the fuel is utilized to provide heat, while 10% is emitted as exhaust.
2) Air Handler: The indoor component of your split AC system or heat pump that includes the blower motor, blower, and controls. It moves air throughout your home. 
3) BTU: (British Thermal Unit) This is a measure of the heat given off when fuel is burned for heating, or the measure of heat extracted from your home for cooling. 
  • For all you science fiends out there, BTU represents the amount of energy required to raise one pound of water one degree Fahrenheit. 
4) Charge: The amount of refrigerant in your AC system 
5) COP: (Coefficient of Performance) For a heat pump, this is determined by the ratio of heating or cooling provided to electrical energy consumed. 
6) Compressor: The part of the outdoor AC unit that maintains adequate pressure to allow refrigerant to flow in quantities that meet the cooling requirements of your home. The compressor sends refrigerant through condenser coils, which changes refrigerant from vapor to liquid, dispersing heat into the outdoor air. 
7) Heat Loss & Heat Gain: Heat loss refers to the estimate of heat lost to the outdoors through the structure of your home. Conversely, heat gain refers to the heat that comes into your home or is generated within the structure from occupants or solar gain. These estimates (determined in BTUs) factor into a load calculation, which our Comfort Consultants use to determine the capacity of heating or air conditioning equipment your home requires. 
8) MERV: This rating measures the efficiency of your air filter, as determined by the size of particle it can capture. The higher the MERV rating of your air filter, the finer it is. 
9) Refrigerant: This substance flows through your AC unit and helps with heat transfer. The transformation of refrigerant from liquid to vapor, or from vapor to liquid, respectively absorbs or gives off heat. 
10) Register: Metal covering on supply vents in your home
11) SEER: (Seasonal Energy Efficiency Ratio) This measures the cooling efficiency of a heat pump or air conditioner. The higher the SEER rating, the more efficient the unit. These ratings usually range from 13 to 20 SEER, although ratings of 21 or 22 are not uncommon. 
Don’t worry, there won’t be a test! Having a basic knowledge of these terms will help you play a more engaged role in the HVAC service or installation process. 
For all of your heating & cooling needs, gives Brandywine Valley a call at 610-692-3900.