Terms and Technical Definitions
AFUE
Annualized Fuel Utilization Efficiency is a measure of your furnace's heating
efficiency. The higher the AFUE percentage, the more efficient the furnace. The
minimum percentage established by the DOE for furnaces is 78%.

Airflow
The distribution or movement of air.

Air-Conditioning and Refrigeration Institute (ARI)
ARI is an industry trade association that develops standards for measuring
and certifying product performance. For instance, ARI Standard 270 provides
guidelines for establishing sound levels for outdoor air-conditioning
equipment.

Air Handler/Coil Blower
The indoor part of an air conditioner or heat pump that moves cooled or
heated air throughout the ductwork of your home. An air handler is usually a
furnace or a blower coil.

Bioaerosols
Microscopic living organisms suspended in the air that grow and multiply in
warm, humid places.

Btu
A British thermal unit is a unit of heat energy. One Btu is the amount of
heat required to raise one pound of water by one degree Fahrenheit. The higher
the Btu rating, the greater the heating capacity of the system.
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Btuh
British thermal units per hour.

CAE
The Combined Annual Efficiency is a measure of the amount of heat produced
for every dollar of fuel consumed for both home and water heating.

Carbon Monoxide
An odorless, colorless, tasteless, poisonous and flammable gas that is
produced when carbon burns with insufficient air.

Central Air Conditioning System
System in which air is treated at a central location and distributed to and
from rooms by one or more fans and a series of ducts.

CFM
Stands for Cubic Feet per Minute. This measurement indicates how many cubic
feet of air pass by a stationary point in one minute. The higher the number, the
more air is being moved through the ductwork by the system.

Compressor
The part of the outdoor air conditioner or heat pump that compresses and
pumps refrigerant to meet household cooling requirements.

Condenser Coil
The outdoor portion of an air conditioner or heat pump that either releases
or collects heat, depending on the time of the year.

Damper
A movable plate, located in the ductwork, that regulates airflow. Dampers are
used to direct air to the areas that need it most. Typically used in a zoning
application.

dB
A decibel is a unit used to measure the relative intensity of sound.
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DOE
The Department of Energy is a federal agency responsible for setting industry
efficiency standards and monitoring the consumption of energy sources.

Dual Fuel
A comfort system that pairs an electric heat pump with a gas furnace,
providing an energy-efficient alternative to the conventional furnace/air
conditioner combination.

Ductwork
The method by which air is channeled from the furnace or the blower coil
throughout your home.

Electronic Air Cleaner
An electronic device that filters out large particles and bioaerosols in
indoor air.

ENERGY STAR®
An EPA (Environmental Protection Agency) designation attached to HVAC
products that meet or exceed EPA guidelines for high-efficiency performance
above the standard government minimums.

EPA
The Environmental Protection Agency develops and enforces federal
environmental regulations. The EPA oversees the nationwide ENERGY
STAR® program.

Evaporator Coil
The part of the air conditioner or heat pump that is located inside the air
handler or attached to the furnace. Its primary function is to absorb the heat
from the air in your house.
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FAQ
Stands for "frequently asked questions."

Garage Heaters
Garage heaters are an excellent product for combating cold garages and
workshops during the winter months. Heating capacities provide warmth for a 1
car garage up to a 4+ car garage application. Separated combustion models
provide heating for hard-to-heat applications. Available in natural or propane
gas, units should be installed by a Lennox dealer/installer.

Heat Exchanger
Located in the furnace, the heat exchanger transfers heat to the surrounding
air, which is then pumped throughout the home.

Heat Pump
A heat pump is an HVAC unit that heats or cools by moving heat. During the
winter, a heat pump draws heat from outdoor air and circulates it through your
home's air ducts. In the summer, it reverses the process and removes heat from
your house and releases it outdoors.

Horizontal Flow
When an air handler or furnace is positioned on its side and circulates air
in one end and out the other. Ideal for attic or crawl space installations.

HSPF
The Heating Seasonal Performance Factor is the heating efficiency rating for
heat pumps. The higher the rating, the more efficient the heat pump. HSPF will
be regulated in 2006 at 7.7.

Humidifier
An indoor air quality device that introduces moisture to heated air as it
passes from the furnace into the ductwork for distribution throughout the
home.

Humidistat
An automatic device used to maintain humidity at a fixed or adjustable set
point.
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HVAC
Heating, Ventilation and Air Conditioning.

Indoor Coil
See Evaporator Coil.

ISO 9000
A family of international standards for quality management and assurance.

MERV Rating
The MERV (Minimum Efficiency Reporting Value) rating of a filter describes
the size of the holes in the filter that allow air to pass through. The higher
the MERV rating, the smaller the holes in the filter, the higher the
efficiency.

Micron
A unit of measure equal to one millionth of a meter, or one thousandth of a
millimeter.

Odors/Chemicals
Air contaminants in the form of gases.

Outdoor Coil
See Condenser Coil.

Particles
Any substances measuring less than 100 microns in diameter. The EPA has found
that small particles (less than 2.5 microns) are responsible for the health
effects of greatest concern.

Programmable Thermostat
A thermostat with the ability to record different temperature/time settings
for your heating and/or cooling equipment.
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R410A Refrigerant
A chlorine-free refrigerant that meets the EPA's newest, most stringent
environmental guidelines.

Refrigerant
A chemical that produces a cooling effect while expanding or vaporizing. Most
residential air conditioning units contain the standard R-22 refrigerant, or
Freon.

Refrigerant Lines
Two copper lines that connect the outdoor air conditioner or heat pump to the
indoor evaporator coil.

Scroll Compressor
A specially designed compressor that works in a circular motion, as opposed
to up-and-down piston action.

SEER
The Seasonal Energy Efficiency Ratio is an energy efficiency rating for air
conditioners. The higher the SEER, the better the energy performance, the more
you save. The DOE's established minimum SEER rating for cooling is 13.00.

Single Package
A heating and cooling system contained in one outdoor unit.
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Split System
An HVAC system in which some components are located inside the structure of
the house and some are located outside. Split systems should be matched for
optimal efficiency.

Thermidistat
Monitors temperature and humidity and adjusts heating or cooling system to
maintain desired levels.

Thermostat
Usually found on an inside wall, this device operates as a control to
regulate your heating and cooling equipment, allowing you to adjust your home
comfort at the touch of a switch.

Ton
Unit of measurement for determining cooling capacity. One ton equals 12,000
Btuh.

Two-Stage Operation
Provides two levels of heating or cooling output for greater temperature
control, energy efficiency and improved indoor air quality.

Upflow
When an air handler or furnace is installed in an upright position and
circulates air through the side or bottom and out through the top. Typically
used in basement, closet and attic installations.
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Variable Speed Motor
A motor that automatically adjusts the flow of warm or cool air for ultimate
comfort.

Ventilator
A system that exchanges stale, recirculated indoor air with fresh, filtered
outside air.

Zoning
A method of partitioning a home into independently controlled comfort zones
for enhanced comfort and efficiency.
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