Does a Window AC Have To Be In a Window?

So, you’re thinking about bringing in a new air conditioner to boost the quality of air conditioning in your home. And after thinking carefully about your options, you feel a window air conditioner would be the best solution.

However, although you know that window ac units traditionally go into the window, you’re wondering whether you can install it in a different location, perhaps through the wall. Maybe your home is a little old and the windows weak. So, you’re wondering if you can window units somewhere else.

Read on to find out why window ACs work best through the window, the dangers of installing a window unit elsewhere, and important precautions if you decide to install your AC through the wall or use it as a portable AC unit on the floor.

Does a Window AC Have to Be in a Window?

No, a window AC doesn’t have to be in a window. Granted, window air conditioners are specifically designed to be mounted in a window so they can easily dispel byproducts (warm air and water). However, with a few modifications, you can use a window air conditioner without a window inside a room. 

What’s a Window AC?

A window air conditioner is a simple air conditioning unit typically installed in the window. It fits into the window frame such that the front faces inside the house to provide cool air to your rooms while the back end faces the outdoors to dispel hot air and other by-products from the AC.

Unlike central air systems and mini-split air conditioners, window air-con packs all the components, including the evaporator coils, condenser coils, and refrigerant lines into one box. They are similar to wall air conditioners in this sense.

How Do Window ACs work?

Window air conditioners rely on cold refrigerant and two air cycles to keep your home cool and comfortable. The first air cycle happens inside the house. Indoor air enters the AC through the return vents and flows over the cold refrigerant-filled evaporator coils.

As it passes over the coils, the refrigerant absorbs the heat from the air, lowering the temperature of the air. Then the now-cool air flows out of the AC through the supply vents. Gradually, this process helps lower indoor temperatures.

The second cycle happens outside the house. Once outside the house, the now-warm refrigerant transfers the heat to outdoor heat which flows out of the outdoor unit.

Why Are Window ACs Installed in the Window?

The main reason window air conditioners are installed in the window is convenience. All air conditioners, including central air systems, have one part of the unit sitting inside the house and the other part outside the house to facilitate a smooth transfer of heat from your home to the outdoor.

It’s the same even for mini-split systems, and is important because air conditioners merely transfer heat – they don’t make heat.

However, the main difference between central air systems or even mini-split systems and air conditioners is that they comprise two distinct parts, a dedicated outdoor unit and a dedicated indoor unit. This makes everything easier.

Wall and window air conditioners are a little complicated because they pack the indoor and outdoor units into one package, for convenience.

The only installation method that enables these two AC types to transfer heat from the indoors to the outdoors is through-the-wall or through-the-window. This way, half of the AC is outside the house and the other half inside the house for easy heat removal.

What Happens if you don’t Put a Window AC unit in the Window?

Several things can happen if you don’t put a window air conditioner in a window. Generally, the AC won’t work normally and may even raise the temperature of the room instead of lowering the temperatures.

So, the first question is – where would you put it if not in the window? In the attic? Perhaps the basement? Or on the floor within the intended room? All these locations are ill-suited to window air conditioners unless you first modify the AC.

For instance, assume that you position a window air conditioner somewhere in your room rather than install it in the window. How would it transfer the heat outside the house? Or are you happy to “dump” the heat inside the room?

If you do, then the entire air conditioning process is pointless and counterproductive. Essentially, you’re subtracting xx joules of heat at the front and returning all the heat to the room at the back of the AC. So, how’s that helpful?

Even worse, don’t forget that air conditioners generate heat from the power they consume; all electronic appliances do. So, ultimately, you end up with the original xx joules + a few more joules of heat, making the room even hotter.

Another issue is condensation. All air conditioners natural dehumidify the room, which is a nice advantage if the AC is working properly. However, the water has to go somewhere.

In properly installed window air conditioners, a drain pipe allows the water to drip outside the house onto the soil beneath. It’s rarely much water. So, the risk of structural damage is minimal.

However, what happens if you decide to “install” the window air conditioner inside your home? Where would the water go? There’s no easy solution.

Does a Window AC have to be in a Window?

Finally, some good news! No, you don’t have to install window air conditioners in a window. Although window installations are the most ideal, you can modify the air conditioner for a different installation method.

For instance, you can modify a window air conditioner for through-the-wall installation. Similarly, you can modify a window air conditioner to work as a portable air conditioner.

How to Vent a Window Air Conditioner in a Room without a Window

Let’s look at a few ways alternative ways to install window air conditioners without creating too many new problems.

Install it Through the Wall

The most straightforward alternative to installing a window air conditioner in the window is to install it through the wall. This makes every sense because window air conditioners work exactly like through-the-wall systems. Only the installation location differs.

You have two options;

Install the window AC on an exterior wall: Through-the-wall air conditioners are installed on exterior walls, anyway. So, the first option you should consider is to install your window AC in a similar style. It works like a charm, except for the small issue of how to seal the hole in the wall when you ultimately decide to uninstall the window AC.

Install it through an interior wall: Interior wall installations present one major challenge – heating. While the main room will get cooled, the one on the otherwise of the wall will become heated. For this reason, if you must install a window AC through an interior wall, we recommend installing it through the garage wall as the garage can live with the heat and condensation.

NB: It’s best to hire an HVAC professional for both processes because boring a hole through your walls is never a good idea in the first place.

Convert it to a Portable Air Conditioner

If you’re not too keen on wall installation, consider converting the wall air conditioner into a portable unit.

The simplest DIY method to convert a window air conditioner is to modify a storage bin to fit around the air conditioner’s rear to capture the heat. Ensure an airtight seal between the bin and the air conditioner.

After that, vent the bin through the window or door (though this isn’t a very good idea). A vent pipe running from the top of the bin through the window, similar to how you’d vent a portable air conditioner, is your best bet.

Can you put a window air conditioner on the floor?

No, you shouldn’t as the window AC need to be in the window opening to remove hot air and condensate outside the house. But, yes, you can, as long as you first convert the window air conditioner into a portable AC.

Can you use a window air conditioner inside a room?

No, you can’t use a window air conditioner inside a room without modifying it. However, you can use a modified window air conditioner inside a room without any hiccups. The most important thing is to find a means to remove the heat and condensate from the room.

Other Ways to Air Condition Windowless Rooms

So, what next if you’re not prepared to install your window air conditioner through the wall and aren’t interested in converting it into a portable air conditioner either?

In that case, you may need to consider alternative solutions to cool your room. We recommend the following;

1. Invest in a Portable AC

Portable air conditioners have a vent pipe that leads out of the window to effortlessly remove hot air from the air conditioner. They also handle condensate expertly. You’ll be notified when the drain pan is full so you can empty it.

Portable air conditioners typically vent through the window. Most manufacturers supply a vent pipe that connects to a hole in the back of the portable AC and goes through the window. Make sure to install the vent pipe correctly to prevent the backflow of heat and other byproducts.

Can you vent a portable AC without a window? Yes, you can vent a portable air conditioner without a window. An easy way to do so is by venting it through the door, ideally a sliding door. Alternatively, you can vent it into the attic or a closet.

2. Buy a Ventless Portable AC

Ventless air conditioners are a little unique. In fact, many people don’t even call them air conditioners because they don’t actually cool the air. Instead, they create the “feeling” of a cooler space by moving air. So, they’re too different from evaporative or swamp coolers.

Swamp coolers work by forcing air through wet cooler pads, resulting in “cooler” air on the other end. Ventless air conditioners work the same way. They contain a tank or reservoir full of water, which keeps strategically positioned cooler pads.

During operation, the blower fan pulls indoor air through the wet pads, resulting in tiny moisture particles or moisture-rich air.

Blowing the moisture-laden air throughout the home creates the feeling of lower temperatures, without necessarily removing heat from the room.


The main takeaway is that it’s best to install a window air conditioner in a window. This installation method guarantees the best window AC performance. However, you can consider other alternatives, especially if you don’t have a window to install your window AC.

First, consider installing the window AC through the wall or modifying it into a portable air conditioner. But if you’re not keen on boring a hole in your walls or modifying your AC, the best solution is to invest in a portable air conditioner or a ventless portable air conditioner. Contact us to learn more.