AFUE is the 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 wasted. The higher the AFUE rating, the greater the efficiency. If a furnace has a rating of 80% AFUE rating, the furnace converts 80% of the fuel that you supply to heat — the other 20% is lost out of the chimney. The most efficient furnaces in the industry have AFUE ratings of up to 96.7%.If you have an older furnace (with an AFUE of approximately 60%), you could save up to 40% on your heating bills by replacing it with a new high efficiency furnace! The cost to replace your old, inefficient furnace is paid back through lower utility bills.

A non-profit, voluntary organization comprised of heating, air conditioning and refrigeration manufacturers. ARI publishes quality standards for testing and rating heat pumps and air conditioners to provide you with a standardized measure of comparison.

Stands for British Thermal Unit — the amount of heat required to raise the temperature of one pound of water by one degree (Fahrenheit). Used to describe a device’s heating or cooling capacity. One BTU is approximately equal to the heat given off by a wooden kitchen match.  BTUh:  The abbreviation for British Thermal Units per Hour. A common measure of heat transfer rate.

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

Commonly used to measure the rate of air flow in an air conditioning system. The higher the number, the more air is being forced through the system.

Part of a split-system heat pump or air conditioner’s outdoor unit that controls the pressure applied to the refrigerant so that it can circulate. It plays a vital role in taking in heat to warm your home with a heat pump or getting rid of heat to keep your home cool.

A device that transfers unwanted heat out of a refrigeration system to a medium that absorbs the heat and transfers it to a disposal point. There are three types of condensers: air-cooled condensers, water-cooled condensers, and evaporative condensers. Most residential systems have an air-cooled condenser.

A series of tubes filled with refrigerant, normally located outside the home, that removes heat from the hot, gaseous refrigerant so that it becomes liquid again.

Part of a refrigerating mechanism which pumps vaporized refrigerant from the evaporator, compresses it, liquefies it in the condenser and returns it to the refrigerant control. It’s the outdoor section of a split system air conditioner or heat pump.

A ratio that compares a heat pump system’s heating efficiency to that of electric heat. For example, a heat pump system with a COP of 3.0 provides heat at 3 times the efficiency of electric heat. A heat pump’s system COP will decrease as outdoor temperatures drop, eventually providing little or no efficiency advantage over electric heat - and that’s the point when your auxiliary heat kicks in to heat your home.

A rating on comfort equipment, similar to the miles per gallon rating on your car. The higher the rating, the more efficient the system and the lower your fuel consumption will be.

An electronic device that filters out large particles and contaminants in indoor air. 

The back-up heat built into a heat pump system. Also known as supplemental or auxiliary heat.

A government program that helps businesses and individuals protect the environment through superior energy efficiency. Products earn the Energy Star rating by meeting strict anti-polution and energy-efficiency guidelines set by the Environmental Protection Agency and the  Department of Energy. Products with the Energy Star rating will help you use less energy and save on utility bills.

Part of a split-system air conditioner or heat pump located inside the home. A series tubes filled with refrigerant cools and dehumidifies the air by converting liquid refrigerant into a gas (or vice-versa). A blower motor then moves air over the coil to either heat or cool your home. It is also known as a cooling coil, blower coil, chilling unit or indoor coil.

The amount of heat gained, in BTU’s, from a space to be conditioned, at the local summer outdoor design temperature and a specified indoor design condition.

The amount of heat lost, in BTU’s from a space to be conditioned, at the local winter outdoor design temperature and a specified indoor design condition.

A unit that both cools and heats your home.  It 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. A heat pump system can be either a split system or a packaged system.

An outdoor temperature, usually between 30° F and 45° F, at which a heat pump’s output exactly equals the heating needs of the home. Below the balance point, supplementary electric heat is needed to maintain indoor comfort.

HSPF is the measurement used to gauge the heating efficiency of heat pumps. (A heat pump’s cooling efficiency is measured by its SEER). The higher the HSPF number, the greater the efficiency and cost-savings.HSPF is a seasonal measure (meaning that it takes into account the fact that the heat pumps rarely for as long as is optimal during Spring and Fall). HSPF can be thought of as the “averaged factor” for an entire heating season. HSPF is calculated by taking the total annual heating requirements, including all energy inputs (defrost and back-up heating energy included) divided by the total electric power used. The industry standard rating system compares BTUs of heat output to watts of electrical energy consumed. There are 3.4 BTUs per watt of electricity; an HSPF of 6.8 corresponds roughly with an averaged factor of 2.  Today’s models of heat pumps are required to have a minimum 6.8 HSPF. Newer heat pumps manufactured after 2005 are required to have an HSPF of at least 7.7. The most efficient heat pumps have an HSPF of 10.

A fuel-saving alternative to traditional heating and cooling systems that combines a furnace with a heat pump. A Hybrid heat system reacts to changing temperatures and automatically adjusts to the most efficient energy saving method available to heat or cool a home. Hybrid Heat is adaptable for gas or electric systems and by using a variable speed fan hot or cool air is distributed consistently and evenly throughout a home.

A series of measurements and studies used to analyze and determine the heating or cooling requirements of your home so that properly sized air conditioning and heating equipment may be installed. This calculation uses information such as the square footage of your home, window or door areas, insulation quality and local climate to determine the heating and cooling capacity needed by your furnace, heat pump or air conditioner.

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.

A measurement of air filter’s ability to remove particlesfrom 3 to 10 microns in size. The MERV scale ranges from 1 (least efficient) to 16 (most efficient).

The portion of a heat pump or central air conditioning system that is located outside the home and functions as a heat transfer point for collecting heat from and dispelling heat to the outside air.

A self-contained heating and/or air conditioning system which has all components located in one cabinet. It is placed outside the home - on the ground, on the roof, or sometimes mounted through the walls of the building.

Refrigerant:  A substance that produces a rcooling effect while expanding or vaporizing.

Refrigerant Lines:  Two copper lines that connect an air conditioning system’s condenser coil (the outdoor unit) to the evaporator coil (the indoor unit).

SEER is the measure of efficiency by which the cooling process of air conditioners and heat pumps is rated. The higher the SEER number, the greater the efficiency, which yields greater energy savings.The SEER is defined as the total cooling output (in British thermal units or Btu) provided by the unit during its normal annual usage period divided by its total energy input (in watt-hours) during the same period.For cooling products sold on the market today, the government requires a minimum SEER rating of 13.0. but if you have an older piece of cooling equipment, you may be operating with a SEER rating as low as 8.0…which means that you’re wasting a lot of energy and money. Consider this: for every $100 you pay to cool your home this summer at an 8.0 SEER, you would get the same amount of cooling AND save $42 if you were operating at 14.0 SEER.

A central air conditioning or heat pump system consisting of two or more major components. The system usually consists of a compressor-containing unit and condenser (installed outside the house) and a non-compressor-containing air handling unit (installed within the building). This is the most common type of system installed in a home.

A sophisticated, programmable thermostat that senses the outdoor temperature, indoor air temperature, and indoor relative humidity. A built-in microprocessor determines the most efficient way to achieve ideal comfort.

A temperature control device, typically found on a wall inside that consists of a series of sensors and relays that monitor and control the functions of a heating and cooling system.

Not 2000 lbs, but a unit of measure used to describe the cooling capacity of an air conditioning system. One ton of cooling is based on the amount of heat needed to melt one ton (2000 lbs.) of ice in a 24 hour period (equal to 12,000 BTUh).

Two Stage Compressors are capable of two levels of operation, a low stage and a high stage. Properly sized equipment will operate 80% of the time in low stage, enhancing efficiency and comfort with lower humidity levels and quieter operation. It’s like getting two air conditioners or heat pumps in one system.

A way to increase your home comfort and energy efficiency by controlling when and where heating and cooling occurs. Programmable thermostats control the timing of when your equipment operates; dampers are used to direct air flow to certain sections or “zones” of your home.