Did you know that 84 percent of homes in the United States have some type of air conditioning? During those summer months, it’s hard to beat the feeling of a cool breeze when you get home. If you’re searching for an air conditioning unit or looking to make a switch, it’s important to know all of your options.

This guide will go over all of the different air conditioner sizes so you’ll be better informed to make the right decision. Every home has different requirements, and you’ll want to consider the budget as well.

Ready to learn more? Let’s get started. 

Types of AC Units 

If you want to know all about the different sizes of air conditioners, you’ll need to know the different types of AC units. This is because the type of AC unit is often correlated with the size. Take a look at the most common air conditioner sizes and types.

Central Air Conditioner

For larger homes that have multiple rooms that need cooling, central air conditioning is the best option. You’re likely the most familiar with this option since it is the most common type. A central air conditioning unit uses a ducted system that pulls heat from the outdoors and pushes cool air through the ducts.

This is also the largest of all the air conditioners. This is because it’s made up of two units, the condensing unit, and the evaporative unit, which are connected by refrigerant tubing. 

Window Units

If you’ve ever walked around a big city during summertime, you may have noticed air conditioners in the windows of older buildings. Window-mounted air conditioners are compact units that fit in windows. They release hot air from the back and inject cool air into the room from the front. 

These are smaller air conditioners and are perfect for single rooms since they can cool with greater effectiveness. 

Portable Units

After window air conditioners proved to be effective, portable air conditioners were introduced. They take in the hot air from the room, cool it, and release it back. There’s a hose that runs from the unit to the window that takes the hot air outside.

Although compact and convenient, these portable units are not as efficient or effective as the other options.

Mini-Split Air Conditioners

If your home doesn’t have ductwork, then ductless, mini-split systems are your go-to. These are mounted on the wall with blowers attached. The tubing connects the indoor and outdoor units and circulates between them.

Each of the rooms in your home will have its own unit that cools just that room. There’s no need to tear up any walls. They’re more energy-efficient but also quite costly and bulky. 

Which Unit Is Right for My Home?

Now that you know about the different types of air conditioning units, it’s time to dive in and see what the best option for your home is. There’s a handful of different things you’ll need to take into consideration before making a purchase. Let’s take a look.

Home Square Footage

The best way to know the size you’ll need is to determine the square footage of the space you’re trying to cool. Once you know that, you’ll be able to get an idea of the BTU (British thermal units). This is how you’ll measure the amount of cooling power needed.

Generally, an air conditioner needs 20 Btu for each square foot of living space. Window air conditioners typically have a cooling capacity ranging from 5,000 to 12,500 Btu. There are other considerations, like your ceiling height, that might call for more cooling power.


Let’s face it, air conditioning can be expensive, and the cost of a unit typically comes from the size and complexity. The cheapest option is a window or portable unit that cools a single room. This isn’t the most effective option for large spaces, however.

A cost-effective option is a ductless system, especially if you’re only cooling a few rooms. An entire home cooled by a ductless system will add up quite quickly.

A central air conditioner is a more expensive option, but it’s effective, popular, and will last you a long time.

When looking at the different options, be sure to think about your budget and the type of space you’re trying to cool. That will give you an idea of which air conditioner to lean towards. 

If you’re replacing an air conditioner, that’s a separate discussion altogether. Click for more information.

SEER Rating

If you’re looking at central air conditioners, you’ll start to see the acronym SEER come up quite often. This is the seasonal energy efficiency ratio, and it’s a measure of how much energy the air conditioner uses to cool a home.

Central air conditioners range from 13 to 24 SEER. Depending on the climate of your location, you’ll want to look at what the right SEER rating is for you. For example, people who live in humid and hot climates should choose an air conditioner with a SEER of 15 or higher.


Finally, you’ll want the peace of mind that the air conditioner you purchased will last you a long time with little to no problems. It’s good to consider warranties with long terms but prioritize what the warranties cover.

Certain units with lifetime warranties may not cover the more expensive aspects of fixing a unit. As you look for a new air conditioner, be sure to ask about the warranty and what exactly it covers.

Air Conditioner Sizes

Although it may seem like an air conditioner is simply a luxurious way to cool off, it’s also imperative in protecting people against the harsh heat. Making the right choice for air conditioner sizes will ensure that you aren’t spending too much money or getting subpar cooling.

Using this guide, you can better understand the different types of air conditioners and what is best suited for your lifestyle. 

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