HVAC Terminology Every Homeowner Should Know

HVAC Terminology Every Homeowner Should Know

Understanding the HVAC terminology that every homeowner should know helps you better manage maintenance on your home. Many terms sound overly technical, but knowing the right ones helps you understand how your system works.

If you understand how your system works, you’ll find it much easier to troubleshoot any problems. It may even save you money.

It also makes it easier to work with your professional service provider. You’ll find you’re both on the same page when discussing repairs or upgrades.

Understanding HVAC Concepts

If you’re shopping for new HVAC equipment, there is some HVAC terminology every homeowner should know before making buying decisions.

Efficiency ratings

Efficiency ratings help consumers make decisions about their appliances. For example, the SEER rating on an HVAC unit rates the efficiency of air conditioning units. It means “Seasonal Energy Efficiency Ratio” and gives you the unit’s cooling efficiency over the summer cooling season.

Load calculations

HVAC equipment comes in a wide range of capacities to suit homes of different sizes. In fact, the units are measured in “size,” often expressed as “tons.”

The correct size of AC unit required for a home depends on its location and the square footage of the home. You’ll even find charts online that provide the tonnage you’ll need for your home.

However, professional technicians take other factors into consideration, including the home’s orientation, the amount of tree canopy cover, and even the configuration of the ductwork.

Heat gain

Heat gain is the amount of heat added to your home from a wide variety of sources:

  • Sunlight on the exterior walls, roof, and through windows

  • Heat generated by appliances

  • Heat generated by people in the room

  • Outside air infiltration

Heat gain is often used during load calculations to design a building HVAC system more precisely.

Air balancing

Professional technicians provide air balancing services that fine-tune your HVAC operation for optimal performance.

A professional air balancing tests and measures airflow at each vent and ensures each room is adequately served. The technician uses precise measurement tools and adjusts fan speed or ductwork size as needed. They also adjust or add duct dampers for better airflow.

The result is superior airflow of conditioned air throughout your entire home.


Refrigeration is the process of transferring heat through the use of chemical refrigerants. These chemicals are converted to gases to absorb heat and then to liquid to release heat. As the refrigerant moves through the lines and changes its state, it effectively removes heat from indoor air.

Understanding HVAC Equipment

Now that you have a better idea of HVAC concepts, you can see how they apply when talking about equipment.

Condensing unit

Also called the “outdoor unit,” this is the part of your home’s AC system that releases the heat collected from inside. It consists of several basic parts:

Condensing coils: The condensing coils hold the refrigerant while it releases any accumulated heat into the outdoors.

Compressor: Once the refrigerant has released the heat, it needs to be converted to a gas again to collect more. The compressor turns it into a high-pressure gas, which moves it back into the building.

Fan: The condenser fan helps remove heat faster by blowing over the condenser coils.

Air handler

Sometimes called the “indoor unit,” this is the equipment in your home that holds the evaporator coils and blower fan.

Evaporator: The evaporator comprises a series of coils where the refrigerant returns to a low-pressure gas state. This allows it to absorb heat to remove it from your home.

Blower fan: The blower motor turns a fan that distributes the cold air produced throughout your home by way of the ductwork.


Ductwork is the system of tubes for distributing air in your home. Generally, the ducts are hidden above ceilings or in chases. Ductwork can be made of fiberboard, flexible tubes, or metal.

Split system

Split System is the term used for the combination of both the outdoor condenser and indoor evaporator unit.

Ductless system

With a ductless system, each room or zone in your home has its own condenser and air handler. They are connected by piping, with the air handler mounted in the room or zone directly.

Heat pump

A heat pump produces both hot and cold air to regulate the temperature of your home. Instead of an electrical coil or gas furnace to produce heat, a heat pump removes heat from the outside air. It does this by reversing the gas/liquid cycle of refrigeration described above. It distributes the heat through your home via ductwork using a blower fan.

Learn More

Not sure what kind of system you have or how it operates? Make an appointment today with the experts at One Hour Air in Miami for your annual HVAC inspection. We can help you better understand and maintain your system.