What Is an HVAC System and How Does It Work?

The invention of central heat and air conditioning has made our lives more comfortable. A reliable flow of heat or air conditioning isn’t something to take for granted. Understanding how your HVAC system operates, including familiarizing yourself with a simple preventive care schedule and budgeting for professional maintenance, can help you keep your home or business comfortable and cut down on repair bills.

What Is an HVAC System?

HVAC stands for heating, ventilation, and air conditioning. An HVAC system controls temperature, air quality, and humidity in a structure’s indoor spaces. While several HVAC system types exist, they all share one common purpose: promote indoor air quality and comfort. HVAC systems play an essential role in ensuring proper ventilation, reducing air infiltration, and maintaining a comfortable environment within a home or building and all of its interior spaces.

How Does an HVAC System Work?

To understand how an HVAC system functions, you want to look at both its heating and air conditioning operations. 

Forced air, steam, and hot water are the three types of heating systems that warm most American homes and businesses. All three share the same components: a centralized heat source, conduits that move the heat throughout the structure, and outlets that release the heat into rooms. Radiant-floor and solar heating are two other types of heating systems available.

Central air conditioning systems piggyback on a heating system by using parts of the furnace and heating system’s ductwork. All air conditioners operate on the same basic principle — they remove the heat from indoor air, transfer the heat outside, and recirculate newly cooled air. A home or office building’s size, climate, and existing heating system are all factors that help determine which air conditioning system will work best. 

What Does an HVAC System Include?

An HVAC system in use

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Now that you understand how an HVAC system works to promote a comfortable climate inside your home or business, let’s delve further into the components that make up two standard HVAC systems: forced-air heating and central air conditioning systems.

Forced-Air Heating System

Your house or business receives heat by a forced-air heating system if its rooms or spaces have grates or grilles in the floors and walls. Air gets heated in a furnace and travels through air ducts into each room, displacing the cold air that’s drawn into return air ducts and back to the furnace.

Cool air enters a heat exchanger through a return air duct. The air passes through a filter, which removes indoor pollutants such as dust from the air. If natural gas powers the furnace, the air gets heated by a flame or an electric heating element. A blower inside the furnace pushes warm air out of the furnace and into your house through ductwork.

Central Air Conditioning System

Central air conditioning systems consist of an evaporator, or cooling coils, and a condenser unit. The evaporator is commonly located in the furnace, while the condenser is outdoors. Both components can also be in a single outdoor unit.

Return air vents pull warm air from rooms. Coils in the furnace filled with refrigerant absorb heat from the air. This heat gets transferred outdoors to the condenser unit, which releases the heat. The refrigerant travels back to the furnace, and the cycle starts again. The air, which is now cool, is delivered back into rooms through vents in floors and walls.

What Is the Difference Between HVAC and Air Conditioning?

A man changing his thermostat. HVAC systems are necessary to distribute conditioned air

Image via Pixabay by Skitterphoto

An HVAC system combines resources from the furnace, central air conditioner, and ductwork to keep the air inside a home or business comfortable during any season. An HVAC system is also responsible for maintaining indoor air quality. As the air conditioner or heater is operating, ventilation components in the system filter the air to remove pollutants from it.

An air conditioner can operate separately from the furnace or ductwork. The most common types of air conditioners include window units and ductless or mini-split air conditioners. Ductless units feature part of the air conditioner inside a structure to distribute the cold air, while the other portion of the system is outside to produce the cooler air.

The following reasons detail why an HVAC system offers more functionality than an air conditioner alone:

  • You can set the desired temperature inside your home or office with an HVAC system. The system will operate on its own to create your desired comfort level.
  • Air conditioners don’t circulate inside air. They pull outside air into the unit, cool it, and blow it inside a room or interior space.
  • With regular preventive maintenance, an HVAC system can help minimize the chances of allergens and other biological growth developing inside living spaces or workspaces. 

Which HVAC Brand Is the Best?

When considering HVAC systems, you’ll discover several well-recognized manufacturers such as Carrier, Lennox, Trane, and Rheem that create top-quality HVAC systems. If you’re selecting an HVAC system when building a new home or multifamily residence, consult our team of professionals at Energy Diagnostics. We can help you determine your home’s energy efficiency through a series of inspections and tests, such as an air leakage test. Using this information, you can select the best HVAC system sized appropriately for your heating and cooling needs.

How Many Years Does an HVAC System Last?

In general, most HVAC systems will last between 15 to 25 years. Many factors affect an HVAC system’s operating life span. These factors include preventive maintenance, proper installation, oversizing, and inordinately high usage demands. The best way to ensure your HVAC system lasts as long as possible is to schedule regular maintenance inspections for your system with an HVAC technician at least once per year. 

Contact Energy Diagnostics for Any HVAC System Concerns

Are you concerned about making your business, home, or multifamily residence energy efficient? How is your home’s HVAC system contributing to your energy usage? For answers to these questions and more HVAC system concerns, contact Energy Diagnostics. We take pride in making the energy code and performance process a stress-free, beneficial experience for our clients. To learn more about our services, including HERS energy evaluations, call us at (800) 390-8091 or send us a message through our website’s contact form.