How Long Can You Leave a Window Air Conditioner Running?

Benjamin Wright
by Benjamin Wright

If you live in a climate that is often hot, the thought of leaving a window air conditioner running all the time probably seems like a great idea. Before you do, though, here are a few things to keep in mind.

Window air conditioners have the ability to run 24/7 as long as you need them without shutting them off. No inner workings of your air conditioner will melt, or break if you run it continuously. However, they do use a lot of energy and can be costly to run on a non-stop basis.

How Long Can You Leave an Air Conditioner Running?

So, now that you have some basic details related to air conditioners, let’s revisit the question, “How long can you leave an air conditioner running?”

The short answer is that it depends. As we have already discovered, many factors play a role in the effectiveness of an air conditioning unit. Each of those factors also make it more or less possible to run the air conditioning unit all the time.

What Is The Environmental Impact Of A Window Air Conditioner?

The environmental impact and resulting energy bills that come from running your air conditioner all the time changes depending on how hard the air conditioning unit runs.

Contrary to what many believe, it actually saves more energy to run an A/C unit at full speed. The caveat is that the unit should only run at full speed in intervals. This means switching the air conditioner off once the room is cool enough.

If you decide to utilize the automatic controls, turning up the thermostat a few degrees when you are not at home will help you keep the room cool without using too much energy.

Window Air Conditioner Smart Home Device

A smart home device is another thing that can help you when you want to leave your A/C unit on all the time. Whether you are using a product from Nest, Google, Samsung, or anything similar, it is possible to program a number of different features into the air conditioner unit.

It is possible to have your air conditioner turn on an hour before you arrive home, for example. Doing so would give you the effect of leaving your air conditioner on all the time, without giving you the same power bills.

It Safe to Leave the Window AC Unit on All Day?

A window air conditioner is built to run 24 hours a day, seven days a week. Normal use is generally safe for the internal components and cords. It is, however, only safe if it is used properly. There is no danger if you are at home. It could be a problem if you are away.

The pressure on the power grid will be enormous if everyone leaves their air conditioners on. To lessen the workload, the best approach is to raise the temperature. When electricity is restored after a power loss, power surges can occur.

Is It Dangerous To Leave Your Window Air Conditioner Running?

Such power surges might put a load on the compressor and cause it to fail. Furthermore, if the AC is powered by power cords drawn straight from the sockets, residential extension cords and even some surge protectors may malfunction, resulting in a fire. The danger is minor, yet still exists.

If you’re at home, you can keep your home at a reasonable temperature by running the window air conditioner all day. If something bad happens, you’ll be there to stop it from being worse.

The sole disadvantage of continuously running the unit is that it may shorten its lifespan. Wear and tear are common with mechanical devices. It becomes more vulnerable the more it is utilized. Allowing it to rest can help it become more useful over time.

Recommend: Lightest Window Air Conditioners

Is It Bad to Keep the Window Air Conditioner Running All Night?

The best answer is that it is debatable. Air conditioners function by drawing in warm air, chilling it, and then releasing the freshly cooled air into the atmosphere. It does not bring the temperature of the air down to a set level. The temperature of a room is lowered through the constant process of taking hot air and cooling it.

So, how long does it take for the window air conditioner to chill a room? It is dependent on a number of factors. What’s the lowest you’re willing to go? It may take an eternity if you want to go too low. It may take considerably longer if your room is large than if it is little. The unit’s size is also a consideration.

If you have the thermostat adjusted appropriately, running the unit all night is not a problem. You can set the temperatures to 80 degrees Fahrenheit for the night if you don’t want the high temperatures to wake you up in the middle of the night or if you don’t want the unit to cycle continually while you are sleeping.

About Air Conditioning Units

To get a better understanding of how long you can leave a window air conditioner running, it is a good idea to look at some of the features that are common to some of today’s biggest brands.


The BTU rating of an air conditioner unit tells you a couple of important things. One is how efficiently the unit will cool a room of a particular size. For example, an air conditioner rated at 8,000 BTU can easily cool a room of 300 square feet.

It is also important to note that higher BTUs often come with larger price tags. That said, it would be more cost-effective to run fewer, high BTU units than it would be to run more, lower BTU units.

Energy Efficiency

Another factor worth looking into is the energy rating of an air conditioner. There is a wide range of energy ratings available. Contrary to what many believe, air conditioner units that are energy efficient are not so because they cool less effectively.

Instead, they generally employ a range of features that are geared towards saving energy. Examples include auto modes, sleep settings, low-power idle states, and more.

Tips To Maximize Efficiency For Your Conditioner

If you want to get the most out of your air conditioner, there are some things that you can do. Many of the things that you can do will ensure that you stay cool without making any unnecessary sacrifices in terms of your comfort or your wallet.

Select the Right Size

Room size is always an important consideration. As already mentioned, air conditioning units are designed for rooms of different sizes. Choosing the right one for your space will go a long way in ensuring maximal efficiency.

Consider 20 BTU per square foot, and 500 BTU per person as a good starting point when selecting the right size. From there, you will need to consider other factors as well. The number of people normally in the room, the amount of sunlight, and the efficiency of the insulation are just a few examples.

Regular Maintenance

Another important factor that will help you make the most of your air conditioning unit is regular maintenance. Regular cleanings and filter changes are necessary to ensure that your air conditioner can continue running well. Try to clean your air conditioner at least once per month.

Lend a Hand

It may seem funny, but your air conditioner does much better with help. Opening enough windows to create a cross breeze is one way that you can assist. Air conditioners get a read on the temperature and attempt to provide enough cool air to bring down the room’s temperature to a predetermined level.

Allowing a room to cool off even just a degree or two before running the air conditioner will make a big difference in how quickly the air conditioner can do its job. If there is no breeze, using a fan can also help.

Related Questions

Is it safe to leave an air conditioner on all day?

It is safe to leave an air conditioner on all day. In most cases, air conditioners are designed to be on all the time. Most modern air conditioners turn on and off at intervals throughout the day depending on the outside temperature.Leaving an air conditioner on all the time can be costly, however. As a result, many people choose to run their air conditioning units in intervals ranging between 2-4 hours at a time.

How long should an air conditioner sit before turning it on?

Air conditioners contain pressurized fluids that are required to create cool air. When moving an air conditioner, these fluids often become disturbed and have a tendency to spread throughout the system.Therefore, after moving an air conditioner, you should always allow an air conditioner to rest for at least 30 minutes. This will allow the fluids to settle properly.

The Choice is Yours

Ultimately, the choice about whether to leave your air conditioner running all the time is up to you. The units themselves can certainly handle being run 24/7, as long as the filters are cleaned on a regular basis.

In most cases, however, there is little need to operate an air conditioner on a full-time basis. Closing windows and doors, as well as using some fans to help circulate air can all help make the air conditioner more efficient.

Also helpful is considering the exact times when you would like to benefit from the air conditioning unit. As there are plenty of tools available to automate the operation of your air conditioning unit, it is possible to achieve full-time comfort with part-time use of the A/C.

Benjamin Wright
Benjamin Wright

Benjamin is a proud homeowner who loves to write about DIY projects and home improvement projects. Traveling, perfecting his home, and spending time with his family are just a few of the many things that keep him inspired.

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