Can you use a window air conditioner without a window?

A window air conditioner is an affordable cooling solution that cools indoor spaces without requiring ductwork.

It works by taking advantage of the power of a blower and fans to discharge warm air outside a house and push cool air into a home.

Window AC units come in handy when a homeowner does not have enough money to purchase central air conditioning.

But can you run an air conditioner without a window?

The conventional wisdom is that you cannot use a window air conditioner without a window. However, there can be an exception if you figure out how to direct the heat produced from the unit outside a room.

Some people come up with different ways of achieving this. A common method is creating a hole inside the room to connect to the outside.

The hole substitutes the window, allowing the heat from the unit to escape outside. Also, many try to convert a window AC to portable AC, but the process proves futile.

What happens if you run a window AC inside?

window air conditioner

The basic principle of a window air conditioner is to move heat from the indoor to the outdoor side.

Therefore, the AC will work like a heater if you run it somewhere inside your house with no window.

That is because the front part of the machine will produce cool air, but the back side will dump a lot of heat that has nowhere to go but inside your house.

Instead of doing this, we’ve created a guide that will help you cool your apartment without an AC.

Can I put a window AC on the floor?

It is not advisable to put a window AC on the floor in your room. It will not be efficient when you place it on your floor.

Furthermore, the unit will not expel heat outside the house but inside, and the water from the pipes in the air conditioner will drip all over the floor.

Can you open a window with an AC unit in it?

It is unnecessary to open a window with an AC unit installed in it. That is because when you open the window, the cool air generated by the air conditioner will escape outside.

But some homeowners make modifications to their windows. For example, they use a piece of wood screwed into the window frame to support the air conditioner and prevent it from falling, thus allowing the window to open.

Note that you must consider how much your AC weighs before you mount it to your window.

Others use an AC support bracket or a custom-made shelf that keeps the unit intact and the window open. However, regardless of the method, opening your windows while an air conditioner is running is unnecessary.

window air conditioner

Can you use a window air conditioner through the wall?

A wall offers an alternative solution to using a window air conditioner without a window.

However, you need the AC to communicate with the outside to avoid generating hot air and spreading it into the room.

You should also take extra precautions when making the frame. But the process is difficult because it requires you to cut through your house’s interior and exterior walls.

Here is how to vent a window air conditioner without a window through the wall.

  • Choose a location on the wall to cut a hole. The area should be at least 30 inches off the floor.
  • Position it at the center of the house and near an electrical outlet.
  • Use a stud finder to locate two stud bays in the wall and mark them.
  • Measure your AC’s dimensions and draw them onto the wall. Then, use a level to level them.
  • Use a plunge router to cut through the wall’s interior along the marks.
  • Bore through the outside wall using a power drill at all four corners of your house.
  • Ensure to cut the insulation.
  • Use the drilled holes to mark an outline on the wall from the outside.
  • Cut through the exterior wall along the outline using a circular saw.
  • Use a hand saw to cut through anything blocking the hole.
  • Position 2×4 blocks level with the top of the cut-off stud.
  • Nail the blocks into the studs on both sides of the opening to offer more support.
  • Use the hardware supplied by the manufacturer to mount the AC bracket.
  • Use a level to ensure the bracket is level.
  • Apply caulk around the exterior of the bracket to prevent water or air seepage.
  • Place the AC unit into the hole.
  • Secure the unit using nuts and bolts or any manufacturer-provided materials.
  • Apply caulk between the exterior of the unit and exterior clapboards or shingles.

You can now plug the unit into a power outlet.

How much of a window AC should be outside?

Your window AC manufacturer’s installation guide will help you understand how much of a window your AC needs to be outside.

Generally, window AC units are suitable for double-hung windows. In other words, they require two operable sashes (top and bottom) that slide up and down and can open to offer ventilation.

During installation, you must tilt the unit slightly away to prevent the condensed water from dripping into the room. The tilt should not be more than one-half an inch.

Do you put water in a window air conditioner?

You do not need to put water in a window air conditioner. Instead, the unit has a cold liquid called a refrigerant that circulates in the pipes.

So, during operation, the AC takes the hot air from the room and passes it over the pipes where the refrigerant flows.

In turn, the refrigerant cools the heat from the air. Since there is condensation involved, adding more water becomes unnecessary.


You cannot use a window air conditioner without a window. The only exception is when you determine the best way to expel hot air from the unit to the outside other than a window.

For example, a hole in the wall can be an alternative. In that case, you will have to create a hole through the wall and install the AC unit.

But avoid running the AC inside your house because it will generate a lot of heat with nowhere to escape, and your room will be too hot.

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