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How do I Choose the Best Basement Air Conditioner?

Tim George
Tim George

Choosing the best basement air conditioner is usually a matter of finding the model that is best for your specific space, your budget, and your lifestyle. There are often several options, each of which typically has its own list of pros and cons. Thinking about what exactly you’re trying to achieve is a good first step for most people. Basements usually stay pretty cool naturally, so cooling isn’t always the most important part of the system. Air circulation is often a top priority, for instance, as is keeping a more or less constant humidity in order to ward off mold and fungal growths. The most involved systems tap into the larger ductwork of your house, and while these are often the most efficient they also tend to be the most complicated and costly to install. If your basement has windows, you might consider a window-mounted model; otherwise, something called a “mini-split” system may be your best bet. If you can, it’s often a good idea to see any machines you’re interested in while they’re working, and talking to people who have direct experience can also help you get your bearings.

Pinpoint Your Motivation

Some basements are extremely damp.
Some basements are extremely damp.

One of the first things you’ll want to do is figure out exactly what you’re trying to achieve with a basement air conditioner. Even though basements tend to be cooler than the upper levels of a house, they also tend toward dampness and dead, stale air due to a lack of ventilation. Air conditioners not only cool the air in most cases, but they also force it to circulate, and may also be able to control things like humidity and general air quality. Your goals may vary depending on how you use your basement and how much time you spend there, but identifying these sorts of things before you start shopping can help you make the choice that’s best for your specific needs rather than simply focusing on the machine that has received the highest ratings or best reviews overall.

Consider Duct and Window Models

Air filtration systems can help combat issues with mold.
Air filtration systems can help combat issues with mold.

Most standard whole-house air conditioning systems operate through a network of internal ducts, most of which are installed during initial construction and are actually built into the structure’s interior. The most effective basement systems connect the basement space to the existing ductwork; this allows uniform control as well as synchronization with the rest of the structure. Getting it set up can often be a major construction project, though, and it’s often quite costly.

Some portable air conditioners incorporate evaporative technology, which uses water to cool and humidify an area.
Some portable air conditioners incorporate evaporative technology, which uses water to cool and humidify an area.

By contrast, some of the least expensive and easiest systems to install are portable units that are mounted in window frames. These vent and pump air from the inside to the outside, and provide cooling through a pressurized system of fans. Many of these can work from even very small windows, but some form of opening is required. Basements that are fully enclosed underground can’t usually accommodate these systems.

Mini-Split Systems

The best choice for most basements is what is called a ductless mini-split air conditioner. Manufactured by several major appliance companies, these units provide advanced energy efficiency, require limited installation, and tend to be much quieter than conventional window units. These units do not require ductwork or special wiring.

A mini-split system is typically made up two components: a slim-line indoor air handler that is wall-mounted or sits freely and a slim outdoor condenser. Coolant from the outdoor condenser is delivered to the indoor handler through small refrigerant lines running through openings in the wall or ceiling that require minimal cutting and drilling. Special models also have filters that provide for added humidity control. Some models might include a dehumidifier or an air filtration system as well.

Ductless mini-splits, compared to other systems, offer more flexibility than conventional units and also tend to be more aesthetically satisfying than window units, which often have a somewhat “clunky” feel. They are also expandable, which is particularly useful in case a single basement air conditioner does not provide sufficient cooling for your basement. It’s often the case that as many as four indoor handlers can be attached to one outside unit. In general, the only cutting or drilling required is a small hole for both connections to the outside unit and water drainage.

Ask Questions and Get a Demo

It’s often the case that the very best way to get a feel for what an air conditioning unit is capable of is to see it in person. If possible, visit showrooms and ask for demonstrations. Things like ease of use and assembly can be big factors. Some manufacturers will include things like delivery and professional installation with the purchase price, and you don’t usually risk anything in asking.

Discussion Comments


@Soulfox -- good advice and here is some more. There are quite a few air conditioner units that actually rely on spraying vapor to keep things cool. That is a problem in a high humidity environment such as a basement.

My wife was looking at one of those as a portable air conditioner because she is hot natured and thought one of those could help keep her cool while the rest of us don't freeze and I cry about high electric bills. In our humid climate, one of those wouldn't be effective at all because you don't get the cooling that comes with pulling humidity out of the air. I can't imagine how ineffective one of those would be in basement.


If you do go with a ductless system, make sure you get one that has a large water reservoir. The problem with basements is often humidity and one of the many great things an air conditioner does is to pull moisture out of the air. There are a lot of inexpensive, ductless air conditioners out there but they usually have one thing in common -- a tiny water reservoir. Buying one of those could defeat the purpose of getting a basement air conditioner.

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    • Some basements are extremely damp.
      By: Steven Baines
      Some basements are extremely damp.
    • Air filtration systems can help combat issues with mold.
      By: askthegeek
      Air filtration systems can help combat issues with mold.
    • Some portable air conditioners incorporate evaporative technology, which uses water to cool and humidify an area.
      By: venusangel
      Some portable air conditioners incorporate evaporative technology, which uses water to cool and humidify an area.