So, What’s an HVAC System (Unit?)

One of the most important systems in any home is the HVAC system. HVAC is an acronym that stands for heating, ventilation, and air conditioning. These systems are everywhere, from cruise ships to single-family homes to condos and office buildings.

They are responsible for providing environmental comfort in buildings, but they also affect the air quality of the structures where they operate. The ventilation process involves using fresh air from the outdoors to provide filtered, temperature-controlled air to the indoors.

How Does an HVAC System Work?

As these environmental systems operate, air from outside is brought through the HVAC unit while contaminants like odors, dust, carbon dioxide, moisture, and bacteria get removed. This happens as part of the ventilation process when the air passes through the unit’s filter (which should be changed regularly). 

The HVAC system is one of the most complex systems at work in any structure. To understand how these units work, there are nine components that you should be familiar with. Those are as follows:

  • Filter
  • Air return
  • Air ducts
  • Outdoor unit
  • Compressor
  • Exhaust outlets
  • Electrical components
  • Blower motor
  • Condenser and evaporator coils

The heating, cooling, and ventilation functions are interrelated, working together to keep you comfortable, safe, and able to breathe clean air in your home.


An air filter is usually constructed of pleated paper or spun fiberglass. The component is enclosed in a cardboard frame and cleans the air that circulates through your system. It can filter out particles that include pollen, dust, dirt, mold spores, fibers, hair and fur, and even bacteria and microorganisms. Filters are available in a wide variety of sizes, so make sure that those you purchase for your unit are the correct size.

Air Return

This is the beginning point of the entire ventilation cycle. At the air return vents throughout your home, the air is sucked into the system, travels through the filter, then passes on to the main system. 

Air Ducts

The air ducts are the channels (they often look like wide tubes) through which air travels to and from the system. The ducts are how air gets to the mainframe of the HVAC system and various rooms in the home, office, or other structure. 

Outdoor Unit

You’ve undoubtedly seen these outdoor units. These components are usually in the backyard, behind the building, to the side, or less frequently, on the roof for homes and other buildings. Along with other components, the fan that controls and provides airflow is located within the outdoor unit. It’s essential to keep it clear of shrubs, leaves, and other debris to avoid overheating your system.


The compressor is another part of the outdoor unit responsible for converting refrigerant to liquid from gas before sending it through to the coils. It’s located in the condenser unit and cools the refrigerant, too. Most people think of it as the heart of the HVAC system, meaning the refrigerant would be like the blood.

Exhaust Outlets

Similar to how a car creates exhaust as it uses fuel for energy, an HVAC system also creates exhaust that must have a way of safely escaping the system (and your house). The exhaust outlets provide this escape route for your unit.

Electrical Components

The electrical components include various parts of an HVAC system and things like the breaker box and the batteries in your thermostat.

Blower Motor

The blower motor is responsible for turning the fan within an HVAC system, thereby drawing air through the main unit. Air cannot move without the blower motor operating efficiently.


There are evaporator coils and condenser coils in an HVAC system; they perform the “heavy lifting” when it comes to heat transfer. The evaporator coils take in the refrigerant that absorbs heat from the air to produce cool, dehumidified air. The condenser coils receive pressurized gas (created by the evaporator coils and refrigerant) as the system fan blows air across them, cooling the gas back into the refrigerant.

Expert Heating and Cooling Service in Portsmouth

When you discover that your system isn’t working correctly, don’t waste time searching “HVAC repair near me” online. Contact Energy Pro Heating & Cooling. 

We serve customers in Virginia Beach, Suffolk, Chesapeake, and all surrounding areas and offer 24/7 emergency service. Our expert technicians are fully trained and have over 60 years of combined experience with all major brands and models of systems. 

Energy Pro Heating & Cooling is a top-rated HVAC company that is insured and licensed, so contact us today for high-quality service throughout Portsmouth, VA, and all surrounding areas.

October 5th, 2021 | Heating and Cooling