AFUE – Annual Fuel Utilization Efficiency

AFUE stands for Annual Fuel Utilization Efficiency. This shows how effective a gas furnace is in converting fuel into energy, the heat you feel. It is not an exact measurement, but is the average of the “thermal efficiency” over an entire heating season. The higher your AFUE percentage, the more energy efficient your furnace is.

Air Handler

An HVAC (Heating, Ventilating, and Air Conditioning) system will typically have an Air Handler. It is a device that circulates air throughout your home or business.

Air Purifier

An Air Purifier is a device that removes contaminants such as pollen, dust, and smoke from the air in a room.

BTU – British Thermal Unit

BTU stands for British thermal unit and is used internationally to measure energy. For HVAC, the Btu is the amount of heat an air conditioner removes in one hour. For other purposes, Btu can also meant the amount of heat it takes to increase the temperature of one pound of water by one degree Fahrenheit.


The compressor is responsible for circulating refrigerant throughout an air conditioning unit.

Condenser Coil

The condenser coil removes heat from the air inside your home or business and releases it into the outdoors. It does this by taking the heat from the evaporator and transferring it outside through the refrigerant.


Some HVAC systems make it possible to have differing temperatures in different parts of a home or business. The damper is the device that regulates the air flow to a room or section of the building. This allows you to change the temperature in one room without affecting another.

Ductless Mini Split

A ductless mini-split is a heating or cooling system located to heat and cool individual sections of a home or business. Instead of a large system with “ducts” spreading heat and cool throughout the home, the air is localized to the room/section. The air is dispersed inside the home, but is connected to a compressor or condenser outdoors by a conduit.


The ductwork consists of the shafts and conduits that distributes or removes air throughout a home or business.

EER – Energy Efficiency Ratio

EER stands for Energy Efficiency Ratio. This is calculated using a standard test condition, not the current temperature. It is basically the amount of energy inputted to the amount of heat removed from the environment in the course of an hour under those set conditions.

Energy Star

A home or appliance that has an energy efficiency rating in the top 25% can become Energy Star Certified. The Energy Star program was started as an incentive for businesses and homeowners to invest in energy efficiency without regulations being forced on them.

Evaporative Cooling

Also known as a swamp cooler, evaporative cooling systems utilize the natural heat transfer of evaporation to cool your home or business. Warm air is drawn through
cooling pads that are moisturized by the swamp cooler pump. When the water evaporates, the cooler air is then circulated through the building while warm air is forced out through openings such as windows or doors.

Fan Belt

A belt is most commonly found in swamp coolers. It powers the blower by connecting it to the motor.

Float / Float Switch

A float or float switch is located inside the drain pan of our unit. Your swamp cooler/evaporative cooler removes heat through the process of evaporation. Typically, this is removed from the unit by a drain line. If this becomes plugged, the drain pan will fill. When it is full enough to raise the float, it trips a switch that shuts down the unit to prevent water overflow and damage.

Furnace Filter

A simple explanation of how a furnace works is that ducts draw the air into it, the furnace heats the air, and ducts then return it to your home. The air that is drawn in contains contaminants such as hair, dust and other particles. The filter catches these contaminants before they can damage your furnace.

Heat Exchanger

The coils in your HVAC unit are heat exchangers. The air passing over the coils is heated or cooled by the temperature of the material –combustible fuel or refrigerant – inside the coils. The air is then recirculated to raise or lower the temperature of your home or business.

Heat load

The heat load is the amount of heat needed to either be added or removed from a room or building to make it the preferred temperature.

Heat pump

A heat pump moves warm air from one location to another. It consists of two parts, one inside and one outside. The indoor unit is an air handler for distribution. The outside unit holds a compressor. When it is hot outside, a heat pump removes the warm air from the indoors to the outdoors. It can be reversed in the winter, transferring warm air from the outdoors to the indoors.

Heat transfer

This is when heat transfers from one material to another. There are three types of heat transfer:

Conduction is when the heat from one object or materials is transferred by direct contact with another object or material. Different substances transfer at varying rates. Conduction is what happens when you touch a cold window, the heat is conducted from your skin to the cooler temperature.

Convection is when heat is moved from one place to another. In terms of your HVAC unit, the fan or blower is involved in convection. It moves heated or cooled air throughout a home or business and alters the building’s temperature.

Radiation is when a heat ray encounters an object. The object receive the energy transference, but the air around it does not. Space heaters utilize radiation to heat surroundings.

HEPA Filter

High Efficiency Particulate Arresting Filters, or HEPA Filters, are used to remove airborne particles such as animal dander, pollen, smoke and many others. The device forces air through a mesh filter that captures the particles before releasing the purified air back into the room. HEPA filters are a great option for someone with asthma or other breathing difficulties.


There are a few ways to explain humidity. The actual humidity is called Absolute Humidity. This is the amount of water vapor divided by dry air. The higher the temperature, the higher the chance of water vapor, or humidity.

Relative Humidity is a little different. This is the ratio of the Absolute Humidity – how much water vapor is actually in the air – to how much humidity there could be for that temperature. For example, a 30% humidity reading means that there is only 30% of the water vapor that there could be.


HVAC stands for Heating, Ventilation and Air Conditioning. This refers to the systems to heat, cool and circulate the air in your home or business.

Load Calculation

Before a heating and cooling system is installed, the size of the unit needed is determined by a load calculation. Your unit should be neither too large or too small, as either situation will not be cost efficient or comfortable. Your HVAC professional will use a Manual J Calculation and computer software to determine the load calculation. Many factors play into this such as size and position of your home or business as well as insulation and window quality. Make sure you get the size that best meets your needs.

Packaged System

Many heating and cooling units have components in various places throughout a building. Heating may be in one area, while cooling may be in another. A packaged system is an HVAC unit that contains all the elements needed in one location.


Refrigerant is a liquid used in air conditioning. It is a cooling agent that chills and dehumidifies air as it passes over the coils containing it. It absorbs the heat from the air inside the house and transfers it outside.

SEER – Seasonal Energy Efficiency Ratio

SEER stands for Seasonal Energy Efficiency Ratio. This helps you determine how much electrical energy is required per hour to output cool air. It is found by dividing the unit’s output by the electrical energy input throughout the cooling season. An efficient unit will have a high SEER.

Smart Thermostat

A Smart Thermostat is an internet connected device that allows home and business owners to control the temperature in the building. Like the name suggests, it can be controlled from a smart phone or other internet devices. It also allows the user to see energy usage and cost, customize a cooling schedule and analyze habits and create a schedule.

Split System

This is an air conditioner or heater with units both inside the building and out. Each house different components of the system. A simple description is that the inside unit contains air handling system while the outside unit holds the compressor and the condenser.

Single Stage HVAC System

A single stage HVAC system has only one Btu rating. A single stage unit is either off completely or running on high.

Two Stage HVAC System

A two stage HVAC system operates at varying Btu ratings, depending on the amount of heat that needs to be removed from or brought into the building.

Swamp Cooler Pump

A swamp cooler pump is a device inside your evaporative cooler that pumps water onto the cooling pads. The water drips through the pads and collects inside the cooler. The pump sends the water back onto the pads, repeating the cycle.

Variable Speed Motor

A variable speed motor alters the inverter speed of the unit based on the static pressure of the building. It will automatically increase and decrease as needed, and is much more efficient..

Zoning system

A zoning system allows you to control the temperature in various parts of a building. Not every room or section of your home or business has the same needs. Each zone possesses its own thermostat for ease of regulation.

Zoning system

A zoning system allows you to control the temperature in various parts of a building. Not every room or section of your home or business has the same needs. Each zone possesses its own thermostat for ease of regulation.