Do You Know These HVAC Terms?

Listen, we know it’s unlikely that you have the entire dictionary memorized. But we don’t want you nodding through the conversations with your technician because you don’t understand what they’re saying. If you ask our technicians questions, they’ll be happy to explain. However, if you want to brush up on some industry terms, check out our vocabulary list below. They’ll have you talking like a pro in no time.

Annual Fuel Utilization Efficiency (AFUE):

A measure of a gas furnace’s efficiency in converting fuel to energy. A higher AFUE rating means greater energy efficiency.

Airflow Volume:

Measured in cubic feet per minute (CFM), this is the amount of air circulated in a space.


A British Thermal Unit is a measurement of the amount of heat required to raise or lower the temperature of one pound of water one degree Fahrenheit.


The device that facilitates the combustion of air and gas.

Burner Orifice:

The opening in the burner through which the gas or fuel passes prior to combustion.


HVAC capacity is the output produced by the heating or cooling unit and is measured in BTUs per hour.

Cubic Feet Per Minute (CFM):

Commonly used to measure the rate of air flow in an air conditioning system.

Charging a System:

Adding coolant, or refrigerant, to an HVAC system.


It’s often called “the heart of the system” because it circulates the refrigerant through a loop. The compressor is a pump that moves the refrigerant from the indoor evaporator to the outdoor condenser and back again.


As warm air is pulled or pushed across the cool evaporator coil the coil perspires, creating liquid, or condensate which is mechanically drained away from the equipment.

Degree Day:

A computation that measures the amount of heating or cooling needed for a building. A degree day is equal to 65 degrees Fahrenheit minus the mean outdoor temperature.

Energy Efficiency Ratio (EER):

The ratio of the cooling capacity (in British thermal units [Btu] per hour) to the power input (in watts). The higher the EER rating, the more efficient the system.

Environmental Protection Agency (EPA):

The United States Environmental Protection Agency is an agency of the US federal government which was created for the purpose of protecting human health and the environment by writing and enforcing regulations based on laws passed by Congress.


Any vent, duct, pipe, or chimney for carrying exhaust gases outdoors.


A device that is designed to monitor or maintain set humidity by reacting to changes in the moisture content of the air.

Refrigerant Charge:

The required amount of refrigerant in a system.

Seasonal Energy Efficiency Ratio (SEER):

A rating used to determine the efficiency of air conditioners. It is the cooling output during a typical cooling-season divided by the total electric energy input during the same period. The higher the rating, the more efficient the system.

Curious to learn more about the SEER rating in your home or interested in getting a system with a higher rating? Let’s talk.