Can you leave a window air conditioner on all night?

You can leave a window air conditioner on all night, but there are factors such as energy efficiency and noise levels that you should consider first.

Window air conditioners are usually more effective and efficient at cooling down smaller spaces, like single rooms, than other types of air conditioners.

Theoretically, you can leave your window air conditioner on all night long, but you should consider the energy this would waste and the noise it would make. It is therefore best to choose an air conditioner (AC) model with a “Sleep” mode for this purpose.

The benefits of window air conditioners

When window air conditioners entered the market, they made air conditioning accessible for households that could not afford or were unable to install larger, central air units in their homes.

These window units are specifically designed to only cool one room at a time, which is what makes them incredibly effective at cooling and energy-efficient compared to other portable and mini-split units that can be too small for a whole floor, but too powerful for just one room.

Can you leave a window air conditioner on all night?

Window air conditioners are usually designed to be able to operate for 24 hours. This means that there is no risk that the components in your air conditioner, such as the fan motor or compressor, will burn out if you leave it on all night long and it is appropriately sized for your space.

Therefore, in theory, you can leave your window air conditioner on all night long. In practice, however, leaving your air conditioner on all night long may waste a lot of energy, because the air conditioner will continue to cycle, and even short cycle, to keep your room at the set temperature throughout the night.

Air conditioners also make a lot of noise while they operate and although this noise may not be as noticeable during the day, at night when you want to sleep, the constant stop and start of your air conditioner can become quite annoying.

These are important factors to consider, because even though there is nothing wrong with leaving your window air conditioner on all night long, this may not necessarily be the ideal choice for while you sleep.

However, it can also get extremely hot and humid in some areas during the night and your window air conditioner may be the only solution to keep you comfortable throughout the night.

This is why many manufacturers now design their window air conditioners with a “Sleep” mode function, which uses less energy and makes less noise during the night, so that you can sleep comfortably and coolly.

Considering the energy-efficiency of leaving your window air conditioner on all night long

When your window air conditioner runs uninterrupted, it can cool down your room to your desired temperature quite quickly.

However, when you leave the window air conditioner on all night long, the thermostat will continuously cause your air conditioner to kick back on when your room heats up outside of the ideal temperature range again.

This will use more electricity, because the fan motors and compressor need to start up every time this happens, which will cause your unit to short cycle, meaning it will not cool or dehumidify the space effectively.

This is why leaving your window air conditioner on all night long will end up costing you a lot in terms of your electricity bills and replacement thermostats in the long term.

Considering the noise of leaving your window air conditioner on all night long

Window air conditioners can be quite loud, especially if the fans and compressor are continuously switching on and off, as with the scenario explained above.

This noise is sometimes not even noticeable during the day when there is traffic and other noises, but it can become annoying when you are trying to sleep, and you should take this into account if you are considering leaving your window air conditioner on all night long.

In this case, a window air conditioner with a quiet operation mode, like this Emerson Quiet Kool EARC15RE1, which only makes about 52 decibels of noise, may be the best option.

Considering window air conditioners with Sleep mode

If you have to keep your window air conditioner on through the night, it is best to consider a model that has a built-in Sleep mode to keep you comfortable while you sleep.

Sleep mode usually uses less energy to cool down your room while you sleep and some of the best models include:

Window air conditioner Price Where to buy
BLACK+DECKER BD08WT6 Window Air Conditioner $499.99 How much area does an 8000 BTU air conditioner cool?
Buy it on Amazon
KEYSTONE Window Wall Air Conditioner $505.99 Can you leave a window air conditioner on all night?
Buy it on Amazon
GE AHQQ06LX Electronic Air Conditioner for Window $423.34 Can you leave a window air conditioner on all night?
Buy it on Amazon

Leave a Comment