Should I keep the windows and doors closed when using an air purifier?

Air purifiers operate by circulating and filtering impurities from the air, such as microorganisms, allergies, pet dander, and many more. At the same time, most of us like getting some fresh air from time to time. But does it affect how your air purifier works? You may be asking yourself, “Should I keep the windows and doors closed when using an air purifier?” or “Do I need to open windows if I have an air purifier?” There are a few factors to consider when we answer this question for you, because it is a little more involved.

Note: If you need answers to common questions about air purifiers, please read our air purifier FAQs.

Related posts

Is it better to open windows or use an air purifier?

It’s hard to tell if opening your windows or running an air purifier results in better air quality since it depends on both indoor and outdoor air quality.

When you open a window, you effectively ventilate your space by allowing some of the contaminants in your indoor air to escape. However, all interior spaces include potentially dangerous particles, especially if the house or room is unclean or has mold. Furthermore, if you open your window for fresh air, make sure to turn off your air purifier. Otherwise, it may not function properly with an open window.

Additionally, cooking scents might become trapped in your house. Both an open window and an air purifier may help in the reduction of these particles. However, opening a window while external pollution levels are high may reduce the quality of your indoor air.

Do air purifiers work with windows open?

Technically, most air purifiers can work with windows open, but not as well as they should. With windows and doors open, you may run an air purifier. However, the performance of an air purifier in a room with open windows is significantly lower than in a room with closed windows.

Air purifiers function by continuously cycling and filtering the air in a room. When you open the windows, the process is disrupted, and your air is exposed to whatever particles are present outside. Consider that by opening the windows, extra contaminants may enter the room, and your air purifier will have to restart the air purification process by cleaning the room’s air all over again. Furthermore, the air purifier will have to work harder to remove the new impurities from the air, which will put pressure on the machine and reduce its performance.

Although some air purifiers are intended to perform best when exposed to fresh air from outdoors, ensure that your air purifier is designed for outdoor use if you open a window while it is operating. Air purifiers intended for indoor use may not be weather-resistant, which can be damaged, especially if they’re placed near an open window or door.

Furthermore, keep a close check on the filter when you run an air purifier with open windows, since it becomes less efficient at cleaning the air in your house when the filter becomes clogged with pollen or other airborne contaminants.

If you have pets, keep them away from the window while the air purifier is operating. Otherwise, pollen and other allergens may be tracked throughout the home.

Should I keep the windows and doors closed when using an air purifier?

When using an air purifier, you should close the windows and doors to enhance the air cleaning efficiency, unless the device is designed for outdoor use. By continuously cycling clean air in a space, an air purifier is most effective with the windows closed. It will keep smog, CO, CO2, dust, and pollen from entering the room and pure air from escaping.

With constant airborne contaminants flowing in from outside, it is hard to create a healthy air status while the windows are left open since your air purifier would have to keep restarting the air purification procedure. This is significantly true if the outdoor air near your open windows and doors is full of smoke, garbage, and particles. You can check the table below to decide under what air pollution conditions to keep windows and doors open or closed.

Air pollutant conditionOpen windows (with air purifier)Open windows (without air purifier)
Polluted neighborhood (city, industrial, mining, next to the highway)NoNo
Pollution from the outdoors (Wildfire, haze season)NoNo
Cooking (burned food, frying, rotten fruits)NoYes
Smoking (cigarette, cigar)NoYes
Chemicals fumes (VOCs, radon, ozone)NoYes
Musty odors (burst pipe, leakage, after shower)NoYes
Fire hazards that require urgent attentionYesYes

Moreover, the larger the opening window and the longer you keep it open, the less efficiently the air purifier runs. It takes many hours to completely clean the air in a standard-sized room. Consider how much longer your air purifier will take to do so if that is interrupted. Keeping the window open means that the air purifier is cleaning more than just the air in the room. It must also purify the air that enters the room from outside. It pushes the air purifier to run continuously, resulting in a higher power cost and a shorter filter life.

According to real-world research, keeping windows closed in a very polluted environment, such as an industrial or metropolitan area, can help lower external pollution by reducing it by up to 60% in a room. It’s better to open windows and doors when an air purifier is not running since it will welcome the circulation of fresh air while clearing indoor air of particles and smoke from cooking, dusting, and smoking.

Do you need to open windows if you have an air purifier?

While it’s not advisable to open windows when your air purifier is on, sometimes you still need to open windows even if you already own an air purifier to clean your indoor air. Open windows and doors while having an air purifier are also beneficial for your respiratory system, as long as they are properly executed.

Your respiratory system has to be maintained, but it may produce a certain resistance to the outside world when the windows and doors are kept closed for too long. As a result, opening the window frequently helps us adjust to the outside environment.

List of the best air purifiers

Furthermore, many air purifiers employ electrostatic dust collection technology, which generates negative ion clusters under high pressure conditions as well as ozone. Long-term usage of such air purifiers with windows and doors closed will result in high indoor ozone concentrations, which will have a negative impact on health. As a result, you can open the windows, but not too frequently. The important thing to remember is to ensure the outside air quality is acceptable. The oxygen concentration of the air in the room will be quite low if the windows are not opened. To guarantee proper oxygen concentration, open the windows in the morning and evening when the outside concentration is low, then close the window and switch on the purifier.

What to consider if I run an air purifier with an open window or door?

There are a few things to think about before opening a window while running an air purifier. Here is a list of things to keep in mind:

  • Your outdoor environment: If you reside in a polluted location or one with nearby automobile exhaust, smoking, or other environmental concerns, you should avoid opening your windows while using an air purifier. Also, due to the high pollen concentration, do not keep the windows open during the spring. That material travels everywhere and shortens the life of your air purifier’s filter. By opening windows, you’re not simply giving the air purifier more work to do. You’re also extending the time it takes to completely clean the air in your home.
  • Your room’s indoor environment: Sometimes there are incidents that require the help of an open window, even when you have an air purifier running. Maybe you burned your food and need to get the smoke out as soon as possible! Maybe the trash piled up because you didn’t have time to clean it up after a stressful week at work. Another possible cause is that you are painting your walls and have to cope with the fumes. It may take some time for an air purifier to complete its task. So, you may open the window for a brief period of time, even if your air purifier is running. An air purifier will continue to work whether the room is closed or not. If you reside in a relatively beautiful place with primarily fresh air, the air inside your house should remain clean and filtered as long as an air purifier is in operation.
  • Your air purifier’s size: You should not open any windows if you have a small air purifier. It will need to run harder for more hours than it normally would to clean the extra air in the room, which results in a decreased life of the air filter and a longer amount of time to clean the room. A large room with a small air purifier may not be clean with an open window.
  • Higher electricity costs: Because the window is open, pure air will escape and unfiltered outside air will enter. When this happens, you might be tempted to increase the fan speed and leave the device running for longer than usual. While the quantity of power that an air purifier consumes is not large (most of today’s compact and efficient models consume 10 watts or less), it may build up over time.
  • Pets in the house: If you have pets, you should keep them away from the window while your air purifier is running. Otherwise, pollen and other allergens may be tracked throughout the home. Your pet’s hair can also get trapped on the air purifier’s filter and clog it, which causes your device to be less effective at cleansing the air inside your home and may shorten its longevity. Always clean your air purifier’s filters to ensure that they are efficient in cleaning the air.

When should I open windows if I run an air purifier?

You SHOULD leave your windows open when running an air purifier if:

  • You’ll close them shortly, or you don’t have any current health or allergy concerns.
  • Your surroundings are relatively clean.
  • Your room has recently been painted or fumed.
  • There are urgent serious indoor air quality issues, such as cooking fire, burns, or rubbish, etc.

You SHOULD NOT open your windows and doors when running an air purifier if:

  • You’ll keep your windows and doors open for a lengthy amount of time.
  • Your external environment is highly polluted.
  • You still have poor indoor air quality, and the air purifier hasn’t finished cleaning it.
  • You have severe indoor air quality issues such as smoking, pet dander, etc. that take additional time to resolve.

Essentially, there is no damage to operating an air purifier with windows open, but it is not as effective. Hence, it’s best to turn the air purifier off while the windows and doors are open.

Here are some general rules to keep in mind:

  • Consider keeping your windows closed if you have a significant source of air quality issues. (Pets, cigarette smoke, etc.)
  • Don’t leave your windows open if you live near a place with a lot of pollution or during busy times like spring.
  • Wait until a room has been thoroughly cleaned and all major pollutants have been eliminated before opening your windows and doors.
  • Open only ONE window at a time to decrease the volume of air from outside and the air disturbance it causes.