Glossary of HVAC Definitions and Terms A-H

Glossary of HVAC Terms

To further assist you in understanding HVAC contractors and how to talk to them about your needs, here are a few common terms known to HVAC contractors that may not be so familiar to homeowners. Refer to this glossary to help decipher "contractor-speak" and communicate more successfully with your HVAC professional.

AFUE - Annual Fuel Utilization Efficiency. This is a measure or rating of the government-mandated effectiveness of a heating or air conditioning unit. The higher the number of the AFUE rating, the greater the capacity of the unit to heat or cool. Consumers should look for an AFUE of at least 78 percent but preferably 85 percent.

BTU - British Thermal Unit. A measurement of how much energy it takes to create heat. A higher BTU heater will generate more heat, for instance, than one rated for lower BTUs.

Coil - The coil is a component - often found in an air conditioner - that consists of a spooled or coiled pipe and takes heat and moisture from the air as the refrigerant inside of it evaporates. The coil will usually "sweat" while operating, the same way a cold glass of lemonade will sweat on a hot day as it cools the atmosphere around it.

Condenser - The part of an air conditioner that contains a compressor. The compressor converts refrigerant into a liquid form and gives off heat in the process, so many condenser units are located not inside a building but outdoors where they will not warm the interior of the house. Condenser units look like a metal box or cage on a concrete pad. They tend to be noisy because they also have a big fan to disperse the warmth into the atmosphere.

Contractor Grade - Items such as building materials, appliances, or tools are graded by their quality. Typically the higher the quality, the higher the price. Contractor Grade is a mid to low-range quality. Homeowners often prefer to pay extra to upgrade from contractor grade to a better grade unless they are trying to save money and complete a project on a limited budget.

Contractor's Lien A legal device that lets contractors attach a claim to a homeowner's property for unpaid work. Until the claim is settled the property is legally encumbered.

Heat Pump - A type of heating and cooling unit that is often more energy efficient, depending upon the climate of the location where it is used. Heat pumps provide both heating and air conditioning, despite the rather misleading name.

HVAC - This is simply an abbreviation that stands for Heating, Ventilation, and Air Conditioning.