HVAC Terms
Annual Fuel Utilization Efficiency (AFUE) measures the gas furnace’s efficiency in converting fuel to actual energy. The higher the rating, the more efficient the unit. For example: A rating of 90 means that approximately 90 percent of the fuel is used to provide warmth to your home, while the remaining 10 percent escapes the exhaust.
Also called an air purifier or electronic air cleaner, it is a device that removes indoor air toxins and particles from the air in the home. They replace the standard filter that sits directly before the furnace or air handler.
An air handler is also called a fan coil, and is used when another heating source is used instead of a gas furnace (such as radiant heating or a heat pump). An air handler combines the fan motor from the furnace (for air circulation) and the indoor coil of from the evaporator coil. An air handler is required for the air conditioner or heat pump to condition air.
This is the amount of heat it takes to raise one pound of water one degree Fahrenheit. For your home, it represents the measure of heat given off when fuel is burned for heating or the measure of heat extracted from your home for cooling.
A humidifier that uses the pressure difference of the supply duct and the return duct of the HVAC equipment to move air over the evaporative pad. In English, this means that it uses the fan motor of your main HVAC system to force air through the humidifier whereas a fan powered humidifier does not.
The output or producing ability of a piece of cooling or heating equipment. Cooling and heating capacities are referred to in BTUs.
Cubic Feet Per Minute. A standard measurement of airflow. A typical system requires 400 CFM per ton of air conditioning.
The heart of the air conditioning and heat pump system. It is part of the outdoor unit and pumps refrigerant in order to meet the cooling requirements of the system.
In an air conditioner, the coil dissipates heat from the refrigerant, changing the refrigerant from vapor to liquid. In a heat pump system, it absorbs heat from the outdoors.
A type of “valve” used in ductwork that opens or closes to control airflow. Used in zoning to control the amount of warm or cold air entering certain areas of your home.
Pipes or channels that carry air throughout your home. In a home comfort system, ductwork is critical to performance.
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.
A ventilator captures heating or cooling energy from stale indoor air and transfers it to fresh incoming air.
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, heat pump or air conditioner.
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).
Located in the furnace, the heat exchanger transfers heat to the surrounding air, which is then pumped throughout your home.
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.
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.
A piece of equipment that adds water vapor to heated air as it moves out of the furnace. This adds necessary moisture to protect your furnishings and reduce static electricity.
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.
A heating and cooling system contained in one outdoor unit. A package unit is typically installed outdoor at ground level or on the roof
A chemical that produces a refrigerating effect while expanding and vaporizing. Most residential air conditioning systems contain R410A or R22 refrigerant.
Overall measure of the efficiency and value of your home comfort system. By combining your purchase price and ongoing operating costs, a payback analysis determines the number of years required before monthly energy savings offset the purchase price.
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.
The combination of an outdoor unit (air conditioner or heat pump) with an indoor unit (furnace or air handler). Split systems must be matched for optimum efficiency.
A unit of measure for cooling capacity. One ton=12,000 BTUs per hour.
The ultimate solution to providing you with consistent, customized home comfort, despite the ever-changing weather.
A type of furnace that draws cool air from the bottom and blows the warmed air out the top into the duct work. This type of furnace is usually installed in a basement or an out-of-the-way closet.
A method of dividing a home into different comfort zones, so each zone can be independently controlled, depending on use and need.
