What Are the Different Types of HVAC Systems? (2023 Guide)

Your home’s HVAC system keeps you warm in the winter, cool in the summer, and can even filter the air that you breathe. But to do all that without breaking the bank, you’ll need to make sure you have the right type of HVAC system for your home.

This article explores the most common types of HVAC systems: how they work, their advantages and disadvantages, and how to tell which type of system is right for you.

Once you have an idea of the type of system you want, check out our tool to help you find the best HVAC installers near you to schedule a consultation.

What Are the Types of HVAC Systems?

Before we talk about individual types of HVAC units, it’s helpful to summarize the different classes of HVAC systems. Below, we’ll take a look at the four main categories that HVAC systems fall into.

• Ductless Systems: Ductless systems—contrary to the name—contain minimal ductwork. Rather than sending conditioned air through the ducts behind your walls, each air handler in a ductless system is connected directly to an outdoor compressor unit via a single small duct, providing greater control over temperature zones but requiring more units to function. A ductless mini-split is a good example of a “duct-free” system.
• Geothermal Systems: Geothermal systems pull heat from the Earth using a network of pipes called a ground loop. The most common type of geothermal system is a ground-source heat pump that uses a mixture of water and antifreeze to add or remove heat from your home—depending on the season. Geothermal systems are extremely cost-effective in the long-term, despite their exorbitant upfront costs. They can be used for heating, cooling, and hot water.
• Heating and Cooling Split Systems: Heating and cooling split systems use separate heating and cooling units to control the air temperature inside your home. A classic example of such a system is a dedicated air conditioner—like a wall unit or window unit—for cooling combined with a furnace for heating. Even though heating and cooling split systems operate independently, they are often controlled by a single thermostat.
• Hybrid Split Systems: Hybrid split systems—sometimes called hybrid heat systems—build redundancy into your home’s heating plan by combining a heat pump and furnace for maximum flexibility. The heat pump provides all of the cooling and most of the heating when the outdoor temperatures are mild. When it gets extremely cold, the furnace takes over heating duty since it can heat more efficiently—even in sub-freezing temperatures.

What Are Common Types of HVAC Units for Homes?

There are many types of HVAC units that work well in residential environments. Here’s a list of the six most common types of HVAC systems that we’ll explore in the following sections:

• Central Air Conditioners
• Furnaces
• Ductless Mini-Split Systems
• Heat Pump Systems
• Packaged Terminal Air Conditioners
• Window and Wall-Mounted Systems

Central Air Conditioners

Central air conditioners are perhaps the most common type of residential HVAC system after window and wall-mounted air conditioners. Central AC systems use a network of ducts and a blower to shuttle cool air around your house, but how the air gets cooled in the first place is a bit more complicated.

The key components of central air conditioning systems that allow it to cool air are the evaporator coil, condenser coil, and compressor. The evaporator coil lives inside your home and contains a chemical called refrigerant. When the warm air in your house contacts the evaporator coil, the refrigerant evaporates and pulls heat from the air, cooling it in the process. The blower then distributes the cool air through the ducts to lower the temperature in your home.

On the outside of your home, the compressor squeezes the gaseous refrigerant, turning it back into a gas and heating it up. The hot air is expelled through the system’s exhaust, and the cycle begins anew. The biggest downside to central air conditioners is that they require a companion heat source, like a furnace.

The video below explains how central AC works to cool your home:

Furnaces

Furnaces are much simpler than central air conditioners. Most residential furnaces use natural gas or oil to heat up a series of fins called a heat exchanger, although some use propane as well. A blower motor forces air through the heat exchanger to increase its temperature before blowing it through a network of ducts throughout your home.

Furnaces are popular because they’re relatively affordable and very energy-efficient. Most gas-powered furnaces reach between 80% and 90% efficiency, with some newer models sitting around an impressive 95% efficiency. They’re also very reliable and require little maintenance compared to other home heating options—like heat pumps.

Unfortunately, furnaces have some downsides. First, furnaces are notorious for drying out the air in your home, which can cause respiratory issues for some people if they don’t use humidifiers to improve their indoor air quality.

Second, even though furnaces don’t require much maintenance when something does go wrong, it often requires an expensive fix. What’s more, a malfunctioning furnace can spew dangerous carbon monoxide (CO) into your home, making it extremely important to install CO detectors throughout your house. You can read our guide to the total costs of furnace replacement if you think it might be time for a new one.

The video below explains how gas-fired furnaces work. Other furnaces work similarly, although the mechanism for providing power is different:

Ductless Mini-Splits

Ductless mini-splits are combined heating and cooling systems that avoid the need for expensive ductwork—making them a popular choice for homes that don’t already have ducts installed. The name mini-split comes from the fact that the system consists of two main parts. The indoor unit acts as an air handler that distributes warm and cool air to your home, and the outdoor unit houses the compressor, resets the refrigerant, and expels the exhaust.

One of the main advantages of a ductless mini-split is that it can be used for both heating and cooling, alleviating the need for two systems. Ductless mini-split systems are more expensive than ductless air conditioning units, but you don’t have to pay to install and maintain an independent heating system, which levels the playing field.

Ductless mini-splits are less efficient in cold weather, especially when the temperature outside dips below freezing. Some homeowners opt for a hybrid system, using a ductless mini-split when the weather is mild and switching to a furnace when it gets cold out. If you only have a ductless mini-split, you’ll still be able to heat your home in the winter, but you run the risk of inadequate heating and will have higher energy costs.

The video below provides a quick look at how ductless mini-splits work to heat and cool your home:

Heat Pumps

Ductless mini-splits are electric heat pumps, but the term heat pump applies to a more general set of heating systems. People usually use the term heat pump to describe a duct system that transfers heat throughout a building—so even though it’s technically correct to describe a ductless mini-split as a heat pump, you’ll confuse people if you do.

Heat pumps are great in moderate climates where the seasonal temperature variation is not too large. They work by exchanging heat between the inside air and outside air, so they rely on a sizable temperature difference to transfer heat efficiently. The biggest advantage to heat pumps is that they can both heat and cool your home, so you don’t have to worry about maintaining multiple HVAC systems.

Heat pumps are more versatile than air conditioners, but they also have higher upfront costs. These upfront costs are offset somewhat by the money you save by not having to purchase a separate heating system. On the other hand, a disadvantage to heat pumps is that they generally have shorter lifespans than air conditioners and furnaces since they run year-round.

You can check out the video below for a brief explanation of how a heat pump works in your home:

Packaged Terminal AC Systems

Packaged terminal AC (PTAC) systems are less common than the other HVAC units we cover in this article, especially in residential settings. PTAC systems are more common in commercial buildings like hotels and office buildings, where you want fine control over the air conditioning in individual rooms.

PTAC units function similarly to ductless mini-splits, with the primary difference being PTAC systems are self-contained and not split between an inside and outside unit. Like a mini-split, a PTAC system usually provides both heating and cooling capabilities, although more affordable systems may only offer cooling. Most people use PTAC to refer to a system that provides both packaged heating and cooling, but, technically, the right term for such a system is a packaged terminal heat pump (PTHP).

PTAC and PTHP systems are less efficient than mini-splits and struggle even more in extreme climates, so they’re not the best option for people who live in colder regions with harsh winters. They’re also more affordable than ductless mini-splits for residential cooling—but not by enough to justify purchasing one over a mini-split. They remain one of the most popular types of commercial HVAC systems due to their low cost and easy maintainability.

The video below shows how packaged rooftop systems function:

Window and Wall-Mounted Units

Window and wall-mounted AC units are the most common type of HVAC system, even though they’re not what most people picture when they hear the phrase “HVAC system.” Window and wall-mounted units are both much more affordable than other air conditioning options, making them the best choice for people on a limited budget.

Window units are especially attractive to people who rent a home or apartment, since they don’t require a permanent installation. They’re also easy to transport, which means the money you spend will continue to benefit you even if you have to move.

Wall-mounted units are more expensive than window units but far less expensive than central air conditioning or a heat pump. The installation process for a wall-mounted unit is far simpler than for a more sophisticated AC like a ductless mini-split, and installation costs are much lower. The main downside is that wall-mounted units can’t match the higher efficiency ratings of central air conditioning or heat pumps. Wall-mounted AC units also don’t last as long as more expensive systems, but the best brands offer high-quality units that give you a lot of bang for your buck.

The video below includes a brief explanation of how window and wall ACs work:

How Do the Types of HVAC Systems Compare?

The following table provides a handy summary of the main differences between the most popular types of HVAC systems.

Which Type of HVAC System Do We Recommend?

We recommend choosing central air conditioning or a heat pump system if you can afford the higher upfront costs. Central air conditioning is great for people who already have a furnace, baseboards, or radiator heating system. They’re efficient, quiet, and very effective.

If you live in a moderate climate, a heat pump is an excellent option that provides both heating and cooling. Heat pumps have higher upfront costs than units that strictly provide cooling, but they’re highly efficient and don’t require an external heating system. Heat pumps typically last for between 10 and 15 years, making them an excellent long-term option.

If you don’t have air ducts installed in your home already, you can still reap the benefits of a heat pump system by getting a ductless mini-split—although you may need several units, depending on the size of the space it will service.