We make finding a quality hvac contractor easy.
Compare furnace estimates now!

Heating and Furnace Glossary

Heating and Furnace Terms Glossary

Below are a few common heating terms and their meaning.

AFUE - Annual Fuel Utilization Efficiency is a rating that denotes the efficiency of gas heating equipment. It is the amount of heating your equipment delivers for every dollar spent on fuel. A higher rating indicates more efficient equipment. This rating is calculated in accordance with the Department of Energy test procedures.

Air duct - See ductwork

BTU - British Thermal Unit - the standard ofmeasurement used for measuring the amount of heat required to raise the temperature of one pound of water by one degree (Fahrenheit).

Carbon Monoxide - An odorless, colorless, tasteless, poisonous and flammable gas that is produced when carbon burns with insufficient air.

Compressor - The part of the outdoor air conditioner or heat pump that compresses and pumps refrigerant to meet household cooling requirements.

Condenser Coil - The outdoor portion of an air conditioner or heat pump that either releases or collects heat, depending on the time of the year.

COP - Coefficient of Performance of a heat pump means the ratio of the rate of useful heat output delivered by the complete heat pump unit (exclusive of supplementary heating) to the corresponding rate of energy input, in consistent units and under operating conditions.

DOE - The Department of Energy is a federal agency responsible for setting industry efficiency standards and monitoring the consumption of energy sources.

Ductwork - Network of enclosed passages (often a tube) used to convey air from a furnace or air conditioner thoughout a house.

Electronic Air Cleaner - An electronic device that filters out large particles and bioaerosols in indoor air.

ENERGY STAR® - An EPA (Environmental Protection Agency) designation awarded to HVAC products that meet or exceed EPA guidelines for high-efficiency performance.

EPA - The Environmental Protection Agency develops and enforces federal environmental regulations. The EPA oversees the nationwide Energy Star® program.

Evaporator Coil - The part of the air conditioner or heat pump that is located inside the air handler or attached to the furnace. Its primary function is to absorb the heat from the air in your house.

Floor, Wall, or Pipeless Furnace - Space-heating equipment consisting of a ductless combustor or resistance unit, having an enclosed chamber where fuel is burned or where electrical-resistance heat is generated to warm the rooms of a building.

  • A floor furnace is located below the floor and delivers heated air to the room immediately above or (if under a partition) to the room on each side.
  • A wall furnace is installed in a partition or in an outside wall and delivers heated air to the rooms on one or both sides of the wall.
  • A pipeless furnace is installed in a basement and delivers heated air through a large register in the floor of the room or hallway immediately above.

Heat Exchanger - Located in the furnace, the heat exchanger transfers heat to the surrounding air, which is then pumped throughout the home.

HVAC - Heating, ventilation, and air conditioning.

Heat Pump - A HVAC unit that heats and cools by transferring heat. In cold weather a heat pump draws heat from outside and circulates it through your home's air ducts. In warm weather it reverses the process and removes heat from your house and moves it outdoors.

Heating Capacity - A measure of the ability of a unit to add heat to an enclosed space.

Indoor air quality - The purity of indoor air.

Lifetime cost - The total cost of something, including purchase, operation, maintenance, and disposal costs.

Micron - A unit of measure equal to one millionth of a meter, or one thousandth of a millimeter.

Programmable Thermostat - A thermostat with the ability to record different temperature/time settings for your heating and/or cooling equipment.

Radiant heat - Coils of electricity, hot water or steam pipes embedded in floors, ceilings, or walls to heat rooms.

Single Package - A heating and cooling system contained in one outdoor unit.

Steam or Hot-Water System - Either of two types of a central space-heating system that supplies steam or hot water to radiators, convectors, or pipes. The more common type supplies either steam or hot water to conventional radiators, baseboard radiators, convectors, heating pipes embedded in the walls or ceilings, or heating coils or equipment that are part of a combined heating/ventilating or heating/air-conditioning system. The other type supplies radiant heat through pipes that carry hot water and are inlaid in a concrete slab floor.

Thermostat - Usually found on an inside wall, this device operates as a control to regulate your heating and cooling equipment, allowing you to adjust your home comfort at the touch of a switch.


About Our Service


Tell us about your project.

Get matched to quality local contractors.

Receive free estimates with no obligation.

What People Say

“We had recently moved to this area and didn't have the ‘built in network’ of friends and family to suggest a good contractor. Knowing you pre-screen the contractors you work with took a lot of pressure off the entire hiring process. ”

M.R. WA

— M.R. WA

More Testimonials



Customer Experience

Are you a Furnace Helper customer? Tell us about your experience - Click Here.

We respect your Privacy!


Are You a Professional?

Care to share your home improvement tips with our readers? Click Here

Would you like more local customers?