Heating and Cooling Terms

AFUE

Annual Fuel Utilization Efficiency. Indicated as a percentage, your furnace’s AFUE tells you how much energy is being converted to heat. For example, an AFUE of 90 means that 90% of the fuel is being used to warm your home, while the other 10% escapes as exhaust with the combustion gases.

BTU

British Thermal Unit. Used for both heating and cooling, BTU is a measure of the heat given off when fuel is combusted. Or for cooling, it’s a measure of heat extracted from your home. (One BTU is approximately equal to the heat given off by a wooden kitchen match.)

Air Handler

The portion of your air conditioner or heating system that forces air through your home’s ductwork.

Carbon Monoxide

A colorless, odorless, highly poisonous gas produced when carbon-based fuels, such as natural gas, burns without sufficient air nearby.

EER

Energy Efficiency Ratings (EER) measure the efficiency with which a product uses energy to function. It is calculated by dividing a product’s BTU output by its wattage.

HSPF

The Heating Seasonal Performance Factor is a measure of the heating efficiency of a heat pump. The higher the HSPF number, the more efficiently the heat pump heats your home.

Heat Pump

A product that works just like an air conditioner in cooling mode; however, in heating mode, the refrigerant flow is reversed and heat is extrated from the outside air too heat your home.

Hybrid Heat

Hybrid Heat systems deliver exceptional performance by using a heating source that provides the most energy-efficient comfort during moderate heating conditions.

MERV

The Minimum Efficiency Reporting Value is the standard comparison of the efficiency of an air filter. The MERV scale ranges from 1 (least efficient) to 16 (most efficient), and measures a filter’s ability remove particles from 3 to 10 microns in size.

SEER

The Seasonal Energy Efficiency Ratio is a measure of the cooling efficiency of your air conditioner or heat pump. The higher the SEER number, the more efficient the system is at converting electricity into cooling power.

Split System

Refers to an air conditioner or heat pump that has components in two locations. Usually, one part of the system is located inside (evaporator coil) and the other is located outside your home (condenser coil).

Ton

A unit of measure for cooling capacity. One ton = 12,000 BTUs per hour.

Zoning

A way to increase your home comfort and energy efficiency by controlling when and where heating and cooling occurs in a home. Programmable thermostats are used to control operating times of the equipment. Dampers are used to direct air flow to certain parts or “zones” of the home.