Everything You Need to Know About Wall-Mounted Air Conditioner Units

When hot weather strikes, keep cool with a ductless AC system

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Photo: Maskot / DigitalVision / Getty Images
Father and daughter playing with baby girl on sofa at home
Photo: Maskot / DigitalVision / Getty Images
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You’ve finally built out that sunroom of your dreams, but now you want to make sure it stays at a comfortable temperature throughout the seasons. Wall-mounted air conditioner units can help cool specific rooms, even if it’s sweltering outside. But wall cooling units aren’t suitable for every home, and while they are energy-efficient, the upfront costs can offset potential utility bill savings. 

Before you set out to install a wall-mounted AC unit, consider the pros and cons of this type of cooling system.

What Is a Wall-Mounted Air Conditioner?

Wall-mounted air conditioning units, also known as wall cooling units or ductless cooling, are appliances that can help cool a single room, even if it lacks windows.

Wall cooling units are especially handy if you’ve decided to add a new guest room or studio space for working from home, but you don’t want to add ducts to connect a central air unit to the new addition.

How Do Wall-Mounted Air Conditioning Units Work?

A wall cooling unit is mounted to the interior wall and connects through the exterior wall to a condenser. The unit takes in air, heat, and humidity, then blows out cold air. Heat and moisture are moved through a conduit, or refrigerant lines, to the outdoor condenser, which then disperses the heat and moisture to the outdoor air.

Benefits of a Wall-Mounted AC Unit

A woman holds a remote control from an air conditioner
Photo: Trik / Adobe Stock

The type of air conditioner you choose can have a big impact on your home. If you’re hoping to lower your energy bills without giving up the feeling of coming into a brisk home on a hot summer day, the ductless AC or ductless heat pump can help you do just that.

  • Energy savings: According to Energy Star, wall-mounted AC units can save up to 30% in cooling costs compared to window air conditioner units, meaning you’ll save energy and money.

  • Skip ductwork: Another benefit to wall cooling is saving the cost of adding ductwork, which can cost $6.50 to $20 per linear foot.

  • Climate control: Wall units can heat or cool a single room, so you can have more control over the temperature. Keep your home office nice and chilly while you work, even when the rest of the home is warm.

Drawbacks of a Wall-Mounted AC 

There are several benefits to installing a ductless AC system, but there are also some drawbacks to consider as well: 

  • Covers a small area: A wall cooling unit will only cool one room, and if it’s an open-plan living room or large home theater, you could need multiple units to cool one room. You may lose out on the cooling savings, too, if you install several units in your home compared to central air conditioning.

  • Drafts: Wall-mounted AC units are attached through the interior wall to the exterior wall, which means they can become drafty if not properly sealed.

  • Maintenance: Your home’s location can impact maintenance requirements for a wall AC unit. If you live in an area that’s humid, dusty, or hot, your wall AC unit will require more frequent care, such as changing filters to prevent dust from ruining the unit.

Cost of Wall-Mounted Air Conditioner Units

Ductless heating and cooling systems cost an average of $7,500, but it can range from $1,200 to $17,000, depending on how many units you need. Several components impact the final cost, from the materials to installation by a local air conditioning installer

  • Condenser (outdoor unit): $750–$5,500

  • Wall mount: $400–$1,500

  • Ceiling mount: $700–$2,000

  • Floor mount: $1,500–$4,000

  • Refrigerant lines: $5 per linear foot

  • Labor: $500–$5,000

A standard indoor wall cooling unit is 12,000 BTU, which cools about 400 square feet of space. Labor costs between $500 and $5,000 for these systems and size, complexity, and ease of access all impact the price.

Winterizing a Wall-Mounted AC Unit

For window air conditioner units, it’s best to remove them and bring them inside during the winter to protect them from freezing temperatures. However, it’s not as easy to remove a wall cooling unit since it’s connected through the wall. You can remove it with some effort, but it’s fine to leave it on the wall. In fact, many of these units double as heaters, so you may even choose to turn on the heat to warm up a spare bedroom or studio space in the winter. 

If you do leave the wall-mounted air conditioning unit up through the seasons, be sure to add weatherstripping on any gaps around the unit. This will help prevent drafts and save you from lost cooling or heating costs.

Central Air vs. Wall Cooling Units

Wall cooling units are a cost-efficient option for homes without ductwork or extensions without ducts. But if your home already has a duct system, installing central air will be less expensive than installing several wall cooling units around your house.

  • Installation: Installing a wall cooling unit is easier than installing central air conditioning. First, you must find a location outside for the condenser. Then, the interior units can be mounted (aim for at least 6 feet above the ground).

  • Coverage: Central air will cool your entire home, or at least where ducts and vents reach. You may need both types of cooling for optimal coverage: central air for your main residence and wall-mounted air conditioners for new additions or accessory dwelling units.

  • Upfront cost: Installing multiple wall-mounted AC units around your entire home could cost two to three times more than installing central air. According to HomeAdvisor, the cost to install ductless air conditioning is about $1,500 to $5,000 for one interior unit and one exterior unit; and installing central air costs around $5,600.

  • Utility bills: Wall cooling units can be about 20% to 60% more efficient than central air when installed properly.

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