Glossary of Heating and Air Conditioning Terms

Following is a glossary of heating and air conditioning terms that can help you in your search for a South Jersey heating and air conditioning system. Call us if you have any questions.

AFUE (Annual Fuel Utilization Efficiency): A standard measurement of efficiency for gas and oil fired furnaces. Given in percentages, this number tells you how much of your fuel is used to heat your home and how much fuel is simply wasted. The higher the AFUE rating, the greater the efficiency. The industry minimum requirement is 78%.

Boiler (Gas or Oil Fired): Heats water for radiator and baseboard hot water systems. This a healthier source of heat than furnace heat, although it is more expensive than the furnace and cannot accommodate air conditioning because it doesn't have ductwork.

BTU (British Thermal Unit): Used for both heating and cooling. BTU is the measure of the heat given off when fuel is combusted. One BTU is equal to the heat given off by a wooden kitchen match.

Capacity: The ability of a heating or cooling system to heat or cool a given amount of space. For heating, this is usually expressed in BTU's. For cooling, it is usually given in tons.

Compressor: Part of a split system heat pump or air conditioner's outdoor unit that controls the pressure applied to the refrigerant, necessary for taking in heat to warm your home or getting rid of heat to keep your home cool.

Condenser Coil: Part of a split-system air conditioner or heat pump. By converting refrigerant that is in a gas form back to a liquid, the coil sends heat carried by the refrigerant to the outside.

Degree Day System: Heating degree days are a measure by how much (in degrees) the outside air temperature was below a certain level. They are commonly used in calculations relating to the energy consumption required to heat buildings.

Damper: A type of valve used in ductwork that opens or closes to control airflow. This is used in zoning to control the amount of warm or cold air entering certain areas of your home.

Downflow: A type of furnace that takes cool air from the top and blows warm air to the bottom – common when your furnace must be located in a second-floor closet or utility area.

Electronic Air Purifier: An electronic device that filters out large particles and contaminants in indoor air. It then electronically pulls tiny particles that have been magnetized, such as viruses and bacteria, drawing them to a collector plate. Sometimes electronic air purifiers are called Electronic Air Cleaners (EAC).

Evaporator Coil: Part of a split system air conditioner or heat pump located indoors. The evaporator coil cools and dehumidifies the air by converting liquid refrigerant into a gas, which absorbs the heat from the air. The warmest refrigerant is then carried through a tube to the outdoor unit (condenser coil).

Fan Coil: An indoor component of a heat pump system, used in place of a furnace, to provide additional heating on cold days when the heat pump does not provide adequate heating.

Furnace (Oil or Gas): Furnaces use oil, gas, or electricity to generate and transmit heat through the duct system of your home; it is a fairly dry heat. If you choose to install central air conditioning, electricity powers the air conditioner in the summer. Two separate units are required – the furnace and the air conditioner.

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

Horizontal Flow: A type of furnace, installed on its side, that draws in air from one side, heats it and sends the warm air out the other side. Most often used for installations in attics or crawl spaces.

Humidifier: A piece of equipment that adds water vapor to heater air as it moves out of the furnace. This adds necessary moisture to protect your furnishings and reduce static electricity.

Load Estimate: A series of studies performed to determine the heating or cooling requirements of your home. An energy load analysis uses information such as the square footage of your home, window and door areas, insulation quality and local climate to determine the heating and cooling capacity needed by your furnace or air conditioner.

Matched System: A heating and cooling system comprised of products that have been certified to perform at promised comfort and efficiency levels when used together, and used according to design and engineering specifications.

Operating Cost: The day-to-day cost of running your home comfort equipment based on energy use.

Recycling: Removing, cleaning and reusing refrigerant.

SEER (Seasonal Energy Efficiency Ratio): 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.

Setback Thermostat: A state-of-the-art electronic thermostat with a built-in memory that can be programmed for different temperature settings at different times of the day.

Split System: 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).

Thermostat: Unit that monitors and controls your HVAC system products.

Ton: A unit of measure for cooling capacity. One ton = 12,000 BTU's per hour.

Upflow: A type of furnace that draws cool air from the bottom and blows the warmed air out the top into the ductwork. This type of furnace is usually installed in a basement or an out-of-the-way closet.

Ventilator: A ventilator captures heating or cooling energy from stale indoor air and transfers it to fresh incoming air.

Zoning: A way to increase your home comfort and energy by controlling when and where heating and cooling occurs in a home. Programmable thermostats are used to control operating times of the equipment. Dampers or zone valves are used to direct airflow or water-steam to certain parts or "zones" of the home.