Air exchanger

– a device that refreshes the air in your home by pulling fresh air into the house and venting stale indoor air outside. The air exchanger is an add-on to your home’s heating / cooling system.

Air filter

– a device composed of fibrous materials that filter dust, dander, pollen, mold spores, bacteria, pet hair and other solid particles from the air. Most home heating systems use either a disposable air filter or a system add-on like a HEPA filter to clean the air and enhance the furnace’s performance.


– the mechanical device in your heating / cooling system that moves air.


– the mechanism in your furnace that is lighted to produce a flame and generate heat.


– the heart of your air conditioning system, which compresses the refrigerant and maintains adequate pressure to meet the cooling requirements of the system.

Condenser coil

– part of your home’s outdoor air conditioner unit that dissipates heat from the refrigerant after it has been compressed, condensing it from vapor into a liquid.


– a device that removes water vapor moisture from the air during summer months, thereby lowering the humidity in your home.


– the sheet metal, fiberglass or flexible plastic pipes / conduits that carry air from your heating / cooling system to the vents throughout your house.


– the Electronically Commutated Motor is an ultra high efficiency programmable motor used in heating and cooling settings. The ECM is significantly more efficient than PSC motors and is easier to control. ECM technology maintains an efficiency of 65-72%.

Evaporator coil

– the portion of your home’s air conditioning system where refrigerant evaporates and absorbs heat from the air being blown over it.


– the first ECM aftermarket motor developed to replace outdated heating and cooling PSC motors in people’s homes, instantly reducing their energy consumption and utility bills. When run on continuous fan mode, Evergreen will instantly upgrade the efficiency of your central heating and cooling system, using 30-50% less electricity than a PSC motor and saving you approximately $125 each year on your electric bill.


– chimney pipe that vents off waste products or gases.

HEPA filter

– a specialized air filter that can trap smaller particles than a standard air filter. HEPA is short for High Efficiency Particulate Air, and can trap at least 99.97 percent of particles of .3 microns. HEPA filters are often added to home heating / cooling systems to help reduce allergens in the air.


– a device that adds moisture to the air during winter months, increasing the humidity in your home.


– moisture in the air, which can make the air feel warmer and more oppressive than the actual temperature.


– a device designed to regulate your home’s humidity by reacting to changes in the moisture content of the air. A humidistat is much like a thermostat except that it turns the system on and off by sensing the humidity level.


– acronym for Heating, Ventilation, Air Conditioning and Refrigeration.


– the blower motor found in many basic heating / cooling systems. Short for Permanent Split Capacitor, the PSC is a basic motor that has one setting: ON. It turns on when the thermostat tells it to, and turns off when the house’s internal temperature reaches the mark set on the thermostat. Significantly less energy efficient that the ECM motor, PSC efficiency ranges from 12-45%.


– a chemical used in air conditioners and other refrigeration applications, which cools the air through a chemical reaction.


– the effect of hot air rising and cooler air settling, resulting in uneven temperatures throughout your home.


– a temperature-sensitive switch that monitors temperature and controls your heating or air conditioning system.


– the grates, grills or other openings in your floors or walls that permit air to circulate through the rooms of your house.

Zone control system

– a system that allows the homeowner to control the heating / air conditioning in numerous “zones” of the house separately using multiple thermostats.