It’s hard to come by an American household or business without an HVAC system. How else would families, business owners, and employees keep themselves cool during the searing summers and harshest winters? Other alternatives like drenching yourself in water every five minutes or wearing layers of clothes, even to bed, aren’t very practical.

While we most certainly can’t understate the importance of a sound HVAC system. Not a lot of people understand how an HVAC system works. Understandably an HVAC system has dozens of internal components that are heard for the average person to keep up with.

If you’re asking, "How does an HVAC system work?" you’ve come to the right place. Below, we give you everything you need to know about an HVAC system and how it works.

What Does HVAC Stand For

The term HVAC stands for heating, ventilation, and air conditioning. The acronym says what an HVAC system does, and pretty succinctly too. The first HVAC was invented way back in 1902 by William Haviland Carrier.

However, modern HVAC systems are a huge leap from what we used to have back then. Still, both the first and contemporary HVAC systems work on the same underlying principles, but there’s a considerable difference in parts. Modern HVACs are more compact, automated and also cost a lot less than the first iterations.

How an HVAC System Works

To understand how an HVAC system works, we first have to look at common HVAC parts. HVAC parts vary from manufacturer to manufacturer, but they all have the following standard parts.

The Air Return

The air return marks the start of the ventilation cycle by drawing in air from the outside. It then passes it through the filter and relays it to the primary system. Air returns need frequent dusting and slight cleaning to keep them in the best shape.

The Filter

Remember, we mentioned above something about the filter. Well, the filter is exactly what it sounds like. The filter is a part that keeps dust and debris from the central system when the air return sucks in air from outside.

You’ll have to replace your filters regularly for them to function as they should. The manufacturer will stipulate how often you need to replace your filter and how to remove and change it. If you don’t replace your filters regularly, your home’s atmosphere will feel stuffy and dust-laden.

This isn’t only uncomfortable, but it can also lead to various health complications. Some of these complications include allergies, asthma, chronic headaches, and even ischemic heart disease. So be sure to spare some change and replace your filter whenever necessary.

Electronic Elements

Electronic elements is a collective term for the electrical components of an HVAC system. Understanding all electrical elements of an HVAC system requires adequate knowledge of electrical engineering. However, you don’t need to know all that, for now.

Electronic parts of an HVAC are prone to malfunction, so you best take good care of them. If anything goes with the electrical components, don’t try to fix it by yourself. The best solution is to call a professional to sort out the issue.

Outdoor Unit

As the name connotes, the outdoor unit is part of your HVAC system that stays outside. It contains a fan that provides continuous airflow to your home. You need to take good care of the fan to prevent leaves from getting into it, causing a huge problem.

Keep in mind that the outdoor unit is also known as a condensing unit or a condenser. You can check out ”What Does a Condenser Do? The Ultimate Guide to Condensers” for a more elaborate explanation of condensers.


These are channels where heated or cool air passes through when you turn the HVAC. Arrange for duct cleaning every three to five years to keep them working correctly.


The compressor is an integral component of the compressor unit. It’s what converts refrigerant gas to liquid form, then conveys it to the coil. The compressor is notorious for most HVAC failures so keep a close eye on it.


Coils are also an essential component of the condensing unit. Coil act hand-in-hand with the refrigerant to cool air as it passes through. Sometimes the coil might freeze, and you might want to check the refrigerant levels.

Types of HVAC Systems

There are plenty of HVAC systems for your home heating and home cooling. Understanding the various types of HVAC systems will help you make a more informed decision the next time you’re in the market for an HVAC. That said, here are the main types of HVAC systems.

Split System HVAC: This is the archetype home HVAC system with components inside and outside the home. It’s made up of a network of ducts that relays air to various rooms. 

Duct-Free Split System: Unlike split system HVACs, duct-free split systems work without ductwork. Instead, they connect every room to a compressor outside. The coils in the system absorb any war air blown over the room to keep the home cool.

Zoned Systems: Zoned systems are quite something because they let you adjust the temperature to different parts of the house. They consist of dampers that block air selectively to the temperature you require.

Humidity Control HVACs: Modern HVACs offer humidity control to regulate the amount of moisture in the air. This is a handy feature during the cold season when the home feels a tad stuffy. However, it’s also more costly than a split system HVAC.

Choose the Right System for Your Home

Now that you know how an HVAC system works, you should be more comfortable the next time you’re in the market for an HVAC system. All you have to do now is find an HVAC system, and that’s within your budget and suits your need. If you already have one, maybe it’s time to upgrade to a better one.

For more informative articles, check out the other pieces on the site.