Glossary

Making informed purchasing decisions and getting the best performance from your home comfort system is easier when you know the common terms.

AIRFLOW

The distribution or movement of air.

AIR HANDLER

The indoor part of an air conditioner or heat pump that moves cooled or heated air throughout the duct work of your home.

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 height the BTU rating, the greater the heating capacity of the system.

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.

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.

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 series of ducts.

CFM

Standards 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 that is being forced through the duct work by the system.

COMPRESSOR

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

CONDENSER COIL

The outdoor portion of an air conditoner that either releases or collects heat, depending on the time of the year.

DAMPER

A movable plate, located in the duct work, that regulates air flow. Dampers are used to direct air to the areas that need it the most.

Typically used in a zoning application.

DB

A decibel is a unit used to measure the relative intensity of sound.

DOE

The Department of Energy is a United States federal agency responsible for setting industry efficiency standards and monitoring the consumption of energy sources.

DOWN-FLOW

Air enters at the top or bottom of the unit and is discharged vertically out the bottom.

DUCT WORK

​A square channel or round tube by which air distributed for the air handler (i.e., rooftop unit, furnace, fan coil or VAV box.

ELECTRIC AIR CLEANER

An electric device that filters out large particles and bio-aerosol  in indoor air.

ENERGY STAR 

A label attached to HVAC systems that meet or exceed the EPA guidelines for energy efficiency. Applies to products 20 tons or less.

EVAPORATOR COIL

The part of the air conditioner or heat pump that is located inside the air handler. It’s primary function is to absorb the heat from the air.

FAN COIL

A unit that includes a cooling and/or heating coil and a fan to move air through the duct work to a room.

Filters for the circulation air and accessories to introduce outside ventilation air may be included.

HEAT EXCHANGER

Transfers heat from one fluid to another without the fluids coming into direct contact with each other.

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 the air ducts. In the summer, it reverses the process and removes  heat from the space and releases it outdoors.

HSPF

The Heating Seasonal Performance Factor is the heating efficiency rating for heat pumps. The higher the rating, the more efficient the heat pump.

HUMIDIFIER

An indoor air quality device that introduces moisture to heated air as it passes from the furnace into the duct work for distribution throughout the building.

HUMIDISTAT

An automatic device used to maintain humidity at a fixed or adjustable set point.

HVAC

Term used for heating, ventilation and air conditioning.

REFRIGERANT

A chemical that produces a cooling while expanding or evaporating.

Refrigerant Lines

​Two copper lines that connect the oudoor air conditioner

SEER

The Seasonal Energy Efficient 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 10.00. This rating only applies to equipment 5 tons and under.

SPLIT SYSTEM

A combination heat pump or air conditioner with indoor components, such as a furnace or blower coil. Split systems should be matched for optimal efficiency.

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 indoor comfort at the touch of a switch.