Is it okay to open your windows? Should you keep them sealed tight? There’s a lot of conflicting advice online. For instance, opening your windows in humid regions may raise your home’s relative humidity too much and make it a breeding ground for mold. But during the COVID-19 pandemic, experts encouraged us to keep those windows open to improve air circulation and reduce the risk of respiratory infection. Then, there’s the added complication of having an air purifier running at home. Looking for some concrete answers? Read on to learn more about using an air purifier with open windows.
What happens when you run an air purifier with the windows open?
There are a few things that happen when you run an air purifier with the windows open, such as:
- Decreased air purifier efficiency. One study in the Building and Environment journal examined using an air purifier with an open window in a nursery environment. The air purifier had a particulate reduction rate of 63% with the window closed and a 46% particulate reduction rate with it open.
- More pollutants to filter. The study above also looked at the environment. One window was right next to a parking lot, increasing the indoor air pollution in the room when the windows were open. Another study in the Science of The Total Environment journal found that using an air purifier with closed windows kept additional outdoor pollutants at bay.
- Potential increase in health risk. If you’re using an air purifier to clean the air of allergens or asthma triggers, opening the window could invite these health hazards in. The EPA encourages to keep windows closed if it poses a health risk to people with asthma.
If you don’t want to risk opening the windows at all, here are some tips for ventilating without windows.
What’s the advice from air purifier manufacturers?
Advice from air purifier manufacturers varies. Some say you can open a window for a limited time or just one window at a time. Others have a hard no-open-window stance. Below are some nuggets of advice from major brand manufacturers.
The do’s and don’ts of running an air purifier with the windows open
Sometimes, it can be necessary to air out your home and get some fresh air in there, especially if you believe there are pollutants present. If you need a (literal) breath of fresh air, below are some tips for having the windows open while the air purifier is running.
What you should do
What you should avoid
In general, a little bit of common sense goes a long way. Don’t open the window too much, if at all, and avoid opening the window during bad air conditions.
You might feel confused because general advice about whether you can open a window while running an air purifier varies. To put it simply, opening a window can reduce the efficiency of the air purifier, as it may now be working against incoming outdoor pollutants. If you do want to open a window, have only one open for no longer than 20 minutes. Never open a window if it might cause issues for someone with allergies or asthma or if air quality is bad.
- Alen. 2023. Can I Open My Windows While Using the Air Purifier? alen.com
- Building and Environment. 2023. Evaluating the Impact of Air Purifiers and Window Operation Upon Indoor Air Quality – UK Nurseries During Covid-19. sciencedirect.com
- Centers for Disease Control and Prevention. 2022. Basic Facts about Mold and Dampness. cdc.gov
- Dyson. Support for your Dyson Purifier Cool Autoreact. dyson.com.sg
- Mila Air. Mila Air: User Manual. milacares.com
- Science of The Total Environment. 2020. Effect of Ventilation Strategies and Air Purifiers on the Children’s Exposure to Airborne Particles and Gaseous Pollutants in School Gyms. sciencedirect.com
- Smart Air. How Does Opening a Window Affect My Air Purifier’s Ability to Clean My Air? smartairfilters.com
- U.S. Environmental Protection Agency. 2023. Ventilation and Coronavirus (COVID-19). epa.govWinix. Get the Most Out of Your Air Purifier. winixeurope.eu