When To Turn Off AC And Open Windows

Your air conditioner produces a steady stream of cool air. The air conditioning unit helps to keep the indoor environment comfortable. However, many homeowners are unsure about when to open the windows. Also, many people do not know when to close the windows and let the air conditioning unit run.

When to turn off your ac and open windows

Ideally, it would help keep all doors and windows closed when the AC is running. However, if you have an open window when the AC runs, you will strain the device. In addition, the cool air that the AC generates will be lost through the open window or door.

At What Temperature should you Open your Windows?

Opening windows is an effective way of letting fresh air into your house without paying anything. However, leaving windows open may create new problems for you. Therefore, you need to understand when to open the windows and keep them open.

Here are important considerations you should use.


The relative humidity is an important factor to consider before opening your windows. Never open the windows when there is excess humidity outside. The relative humidity is measured in terms of dew point. The dew point is the temperature at which the droplets of water in the air change into liquid form.

Leave your windows open when the relative humidity is low. You can use your weather app to check the humidity levels. Ideally, the indoor home temperature should be between 70 degrees Fahrenheit to 75 degrees Fahrenheit. The outside temperature or dew point should be under 67 degrees Fahrenheit.

Seasonal Air Quality

Seasonal air quality is another important factor to consider before opening the windows. Particulate matter, including dust and pollen, determines the seasonal air quality.

When there is a lot of dust and pollen in the air, the quality drops. These particles can trigger serious allergic reactions in people.

You can check the seasonal air quality using any available weather tools. It is proper to be opening windows when seasonal air quality is good or moderate but not poor.

Should you Turn off AC When Opening Windows?

You should turn off your AC when opening windows. This will ensure the air conditioning process is energy efficient. It will keep the cool air indoors while keeping your electricity bill low. Opening windows while your air conditioning unit is running will lead to high electricity bills.

What Happens When you Switch Off your AC?

When you switch off your air conditioner, it does not consume electricity. Thus, on the surface, switching off your air conditioner means that you will save money. However, any other things happen when you switch off your air conditioner.

The room temperature rises steadily when the air conditioner is off. When you finally switch on the air conditioning unit, the room temperature may be quite high. Your air conditioning unit will consume more electricity and work harder. By the time you achieve temperature drops, you will pay more bills.

During summer, the temperatures may rise rapidly. If you switch your air conditioner off, food may begin to go bad. In addition, the refrigerator will consume more energy to keep the food cool. This, again, will lead to high heating and cooling cost.

When can you Turn Off your AC and Open the Windows?

You can turn off your air conditioning unit and leave the windows open when the outside air is not very hot. If you have those summer days when the heat outside is not excess, you can open the windows and switch off the air conditioner for a while.

Also, leaving the room window open helps increase air supply and more sunlight. The light from the sun is good for preventing excess humidity build-up inside your room.

Also, the open windows will increase the circulation of oxygen inside your house. This will make the indoors comfortable and healthy.

You can switch off your air conditioning system and open the windows when you need to conserve energy. Using this strategy during summer will cut down your heating and cooling costs.

This will eventually save money spent paying for electricity to run the air conditioning system.

When should you not Turn off your AC and Open the Windows?

The windows in your home should not be left open when there is excessive moisture in the air. High humidity levels are bad for your air conditioning system. If you open the windows during such a time, you will let in air that carries a lot of moisture.

Humid air is always warmer than dry air. The excess moisture in humid air will make your home uncomfortable. This occurs especially during the night when you open the windows.

Your air conditioning system will work harder to maintain the indoor temperature. Thus, the air conditioning unit will consume more energy to cool the air.

When the air conditioner overworks to maintain the temperature, you pay more in the long run. Thus, the exterior heat makes your energy costs rise exorbitantly. Therefore, you should not turn off your AC and open the windows when the relative humidity is high.

Instead, you may have to turn on the ceiling fans to maximize airflow when the air conditioner is off. This will prevent the build-up of hot air indoors.

What Happens if you Turn your AC On and Open the Windows?

Turning your air conditioner on and leaving the windows open is wrong. Unfortunately, many wrong things take place when you adopt this strategy. First, you will not cool the air inside your home properly if you open the windows when the conditioner runs.

Your air conditioning unit is designed to cool the air inside your home. Opening windows lets the cool air escape to the outside. Thus, you will not maintain the ideal temperature in your home as long as the windows are open. All the cool air will leave through the windows, and more warm air will come through them.

Second, when you leave the windows open and your AC running, you may end up with a damaged air conditioner. Moving air from outside contains a lot of particles, including dust and pollen.

When the particles find their way into your air conditioning unit, they may coat the thermostat. When the thermostat does not function properly, your entire unit will not effectively cool the air in the home.

How can I Keep my Room Cool Effectively? 

Although using air conditioners is one of the most effective ways of keeping your room cool, there are many other things that you can do. An air conditioner will keep your house cool as long as you use it properly.

Here are some of the strategies you can use to complement air conditioners.

  1. Keep the Blinds Drawn: Keeping the blinds drawn stops air from outside that usually enters the room faster. Air from outside may contain a lot of moisture than the air inside the room. When such air rushes into the room, it forces your air conditioners to overwork to maintain the temperature. Also, keeping the blinds drawn prevents cool air from leaving the room fast.
  2. Insulating your home ensures that you do not have particularly warm areas in your room when you turn the air conditioner on. Having such areas in your home leads the air conditioner to overwork. However, if your home is properly insulated, the cool air will remain inside and the heat outside.
  3. Install window tints will prevent excessive light from the sun from entering your room. The light can effectively warm the air and walls in your home. This will make the cooling process more demanding and expensive.

Should I Keep the Windows Open Often?

It would help to keep the windows closed when the air conditioner is running. However, there are many situations where you should keep the windows open.

Breathing in the fresh air will help you feel much better and refreshed. If you keep the windows closed for a long time, the air inside your room becomes stale.

Toxins, including spores and dust, build up in the air. Breathing such stale air makes you feel tired and sick. Leaving the open windows lets in fresh air for your comfort.

Opening windows often helps to make your home energy efficient. In addition, when the air outside is relatively clean and less humid, letting it in helps to reduce the pressure on your air conditioner.

It will also save you money in the long run. Yet, it would help to keep an eye on humidity to ensure that you do not let in humid air and mess up with the cooling process.

It would help keep the windows open to maximize the heating and cooling processes. This works well if your house is properly insulated. The fresh air from outside will help to keep the home comfortable.

Also, the cooler air inside will remain within your house during the day and night. If your house is not properly insulated, the heating and cooling processes.


Saving money is one of the key factors to consider when choosing whether to turn off your AC and open the windows. It is good to keep the windows closed while the air conditioner runs. However, you may open the windows if the air outside is cooler and less humid.