Glossary of Terms

ADVANCED RECIPROCATING COMPRESSOR

An advanced reciprocating compressor is a type of compressor that uses pistons to compress air and move it at high pressure. This process generates higher pressure and efficiency in an industrial system.
 

AFUE

AFUE is an acronym for Annual Fuel Utilization Efficiency. Indicated as a percentage, your furnace’s AFUE tells you how much energy is being converted to heat. As an example, an AFUE of 90 means that 90% of the fuel is being used to warm your home while the other 10% escapes as exhaust.
 

AIR HANDLER

An air handler is the portion of your air conditioner or heating system that forces air through your home’s ductwork.

BTU

BTU stands for British Thermal Unit. Used for both heating and cooling, BTU is a measure of the heat given off when fuel is combusted. For cooling, it’s a measure of heat extracted from your home (one BTU is approximately equal to the heat given off by a wooden kitchen match).

BTUH

A British Thermal Unit (BTU) is the unit of heat required to raise one pound of water by one degree Fahrenheit. BTUH stands for British Thermal Units per Hour and is used as a benchmark for heating systems to estimate their capacity.

CAPACITY

Capacity is 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.

CARBON MONOXIDE

Carbon Monoxide is a colorless, odorless, highly poisonous gas produced when carbon-based fuels, such as natural gas, burn without sufficient air nearby.

CFM

CFM stands for Cubic Feet per Minute and is used as a measurement of airflow that indicates how many cubic feet of air pass by a stationary point in one minute. The higher the number, the more air is being forced through the system.

COMPRESSOR

A compressor is a part of a split-system heat pump or air conditioner’s outdoor unit that controls the pressure applied to the refrigerant. This is necessary for taking in heat to warm your home with a heat pump or getting rid of heat to keep your home cool.

CONDENSER COIL

A condenser coil is part of the outdoor portion of a split-system air conditioner or heat pump. By converting refrigerant that is in a gas form back into a liquid, the coil sends heat carried by the refrigerant to the outside.

DAMPER

Dampers are a type of “valve” used in ductwork that opens or closes to control airflow. These are used in zoning to control the amount of warm or cool air entering certain areas of your home.

DB

Decibels (dB) are a unit measuring the intensity of noise. As an example, 120 decibels are the equivalent of a person yelling as loud as possible.

DOWNFLOW

Downflow is a type of furnace that takes cool air from the top and blows warm air to the bottom of a system. This is commonly used where furnaces are located in a second-floor closet or utility area.

DUCTWORK

Ductwork refers to hollow pipes used to transfer air from the air handler to the air vents throughout your home. Ductwork is one of the most important components of a home heating and cooling system.

EER

The Energy Efficiency Rating (EER) measures the efficiency with which a product uses energy to function. It is calculated by dividing a product’s BTU output by its wattage.

ELECTRONIC AIR CLEANER (EAC)

EAC is an electronic device that filters out large particles and contaminants in indoor air. It then electronically pulls out tiny particles that have been magnetized, such as viruses and bacteria, drawing them to a collector plate.

ENERGY SAVER SWITCH

An energy saver switch causes the air conditioner’s fan and compressor to cycle on and off together, reducing energy use.

ENERGY STAR®

ENERGY STAR® is a government-backed program helping businesses and individuals protect the environment through superior energy efficiency. Products with the ENERGY STAR® rating will be efficient and save costs on energy bills.

EVAPORATOR COIL

An evaporator coil is 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 (or vice versa). A blower motor, typically in a furnace, then moves air over the coil to either heat or cool your home.

FAN COIL

Fan coils are an indoor component of air conditioners or heat pump systems used in place of a furnace and evaporator coil to change the refrigerant from a gas to a liquid (or vice versa) and blow air over the coil to cool or heat your home. 

LOAD ESTIMATE

A load estimate is 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 or door areas, the insulation quality present, and local climate, to determine the heating and cooling capacity needed by your furnace, heat pump, or air conditioner. When referring to heating, this is often known as a Heat Loss Analysis, since a home’s heating requirements are determined by the amount of heat lost through the roof, entryways, and walls.

LOW BOY

A low boy is a type of furnace configuration in which the furnace is lower in height and occupies more floor space.

MATCHED SYSTEM

A matched system refers to a heating and cooling system comprised of products that have been certified to perform at promised comfort and efficiency levels when used together and according to design and engineering specifications.

MERV

The Minimum Efficiency Reporting Value (MERV) 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 to remove particles from 3 to 10 microns in size.

OPERATING COST

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

PAYBACK ANALYSIS

Payback analysis refers to a financial metric determined by the amount of time an investment needs to pay for itself. This is calculated by dividing the initial cost by the net annual cash flow the investment generates, such as the amount of money saved on a heating bill every month after the installation of new insulation.

PURON® REFRIGERANT

Puron® refrigerant is an environmentally sound refrigerant designed to not harm the earth’s ozone layer. Federal law requires that all manufacturers phase out ozone-depleting refrigerants in the next few years. Puron® refrigerant is approved by the U.S. Environmental Protection Agency as a replacement for Freon (R-22).

R-22 REFRIGERANT

R-22 is a single-component HCFC refrigerant with low ozone-depletion potential. It has long been used in a variety of air conditioning and refrigeration applications in a variety of markets. Per U.S. Environmental Protection Agency regulations, the new R-22 cannot be used in new systems effective in 2010 (although service quantities of the refrigerant may be produced until 2020).

RECIPROCATING COMPRESSOR

Reciprocating compressors are a type of compressor used in air conditioners that compress refrigerant by using a type of “piston” action.

RECLAIMING

In heating and cooling systems, reclaiming is the action of returning used refrigerant to the manufacturer for disposal or reuse.

RECYCLING

Recycling in HVAC refers to removing, cleaning, and reusing refrigerant.

REFRIGERANT LINES

Refrigerant lines are two copper lines that connect the condenser (outdoor) coil to the evaporator (indoor) coil.

SCROLL COMPRESSOR

A scroll compressor is a specially designed compressor that works in a circular motion instead of up and down piston action.

SEER

The Seasonal Energy Efficiency Ratio (SEER) 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.

SETBACK THERMOSTAT

A setback thermostat is 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.

SINGLE PACKAGE PRODUCT

A single-package product is an outdoor unit that contains both a heating and a cooling system.

SPLIT SYSTEM

A split system refers to 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 of your home (condenser coil).

THERMIDISTAT™ CONTROL

The Thermidistat™ Control monitors temperatures both inside and outside a building, as well as indoor humidity, and adjusts system operations to maintain the temperature and humidity levels set by the homeowner.

THERMOSTAT

A thermostat refers to any device that monitors and controls your HVAC system products.

THERMOSTATIC EXPANSION VALVE

A Thermostatic Expansion Valve (TXV) is a precision device used to meter the flow of liquid refrigerant entering the evaporator at a rate that matches the amount of refrigerant being boiled off in the evaporator.

TON

A ton is the unit of measure for cooling capacity. One ton = 12,000 BTUs per hour.

UL

UL is an objective, non-profit organization that tests and rates electrical products for public safety.

UPFLOW

Upflow is 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

Zoning is a way to increase your home comfort and energy efficiency by controlling when and where heating and cooling occur in a home. Programmable thermostats are used to control the operating times of the equipment. Dampers are used to direct airflow to certain parts or “zones” of the home.