Where a portable air cleaner is placed, how it’s operated, and how it’s maintained will change how effectively indoor air pollutants are removed.
Where to Place Your Portable Air Cleaner
Which Room
Choose a room where you spend most of your time. If possible, pick a room that’s not very big. If the room is bigger than the portable air cleaner is designed for, it will be less effective. Learn more about choosing a portable air cleaner.
Consider creating a cleaner air room. Watch a video and learn how to create a cleaner air room, EPA.
Where in the Room
Put your portable air cleaner in a dedicated space. Do not place items on top off or next to the air cleaner. Choose a location where the air cleaner is:
- Away from exhaust vents so filtered air stays in the room.
- Unlikely to be unplugged.
- Away from walls and furniture that could block the flow of air.
- Away from drafts like open windows, doors, or air supply vents.
- Off the ground, if possible
For places like classrooms, long-term care facilities, and childcare facilities, avoid spreading airborne infectious diseases by ensuring air is not blowing directly from one person to another.
While the air cleaner is on, keep windows and doors closed to make air cleaning more effective. This includes doors to the outside as well as inside doors.
When and How to Use Your Portable Air Cleaner
Portable air cleaners can be used at any time to remove indoor air pollutants. They are especially useful when there is a source of particles like an airborne disease outbreak or wildfire smoke.
Use your portable air cleaner before, during, and after pollutants are present.
For commercial buildings and schools, start portable air cleaners one hour before students and staff arrive. Continue to run the air cleaner while there are people in the building. Turn off air cleaners when people leave the building.
When air quality events like wildfire smoke occur, use your portable air cleaner during the event and at least a few days after the event is over.
Turn Off Technologies Other Than Filtration
If you already have a portable air cleaner with additional technologies like UV light or ionizers, turn off those functions if possible. Do not use essential oil functions.
Additional technologies can produce harmful air pollutants. See choosing a portable air cleaner for more information.
Fan Speed
Higher fans speeds reduce pollutant concentrations more effectively. Run your portable air cleaner at the highest fan speed with a comfortable noise level.
Use the “auto” setting, if available, to automatically adjust the fan speed, except during periods of airborne disease. An “auto” setting based on a particulate matter (PM) sensor is best.
Adjust Portable Air Cleaner Settings to Encourage Use
Noise
Higher fan speeds are more effective when removing pollutants but can generate more noise. To reduce noise:
- Use the “auto” setting, if available. Except during periods of airborne disease.
- For homes, if your air cleaner doesn’t have an “auto” setting, keep the fan at a speed that has a comfortable noise level. Turn the speed up while you are cooking, cleaning, or doing other activities that generate indoor air pollution, or if the outdoor air quality is bad.
- If an air cleaner is too loud at a high fan speed, consider using multiple air cleaners around the room at a lower fan speed.
The Environmental Protection Agency (EPA) recommends keeping indoor noise levels below 45 decibels (dB). 40 dB is roughly the noise level of a humming refrigerator. 80 dB is about the noise level of a leaf blower. You can use the Sound Level Meter App, CDC or a similar app on a smart phone to measure noise levels.
For spaces like schools, childcare facilities, adult care facilities, or offices, check for noise requirements.
Tampering
Check if your air cleaner’s display can be locked if you’re concerned about tampering. If the portable air cleaner is in a public or community space, remind people why it’s important to keep it on.
Display Brightness
Check if your air cleaner’s display can be turned off if the device is too bright.
Maintain Your Portable Air Cleaner
Filter Replacement
Replace filters according to the air cleaner’s indicator or the manufacturer’s recommendations. Some air cleaners have multiple filters that each need to be maintained.
Unplug the air cleaner before changing the filter. Consider replacing it outside to avoid spreading dust inside. If the filter is changed indoors, ventilate the room, clean the room with a HEPA vacuum cleaner, and wipe surfaces with a damp cloth afterward. Make sure the new filter fits well inside the air cleaner with no air gaps.
If you have a do-it-yourself (DIY) box-fan filter, replace the filter after poor air quality events and when the filter looks dirty.
Consider replacing filters after poor air quality events. Poor air quality events include wildfire smoke or periods when the Air Quality Index (AQI) is in the “Unhealthy for Sensitive Groups” category or higher. If the filter changes color or the air flow coming out of the air cleaner weakens, it’s probably time to change the filter.
Have extra filters available, especially during wildfire smoke season.
Most Filters Cannot be Washed
HEPA and carbon filters cannot be washed and must be replaced. Washing HEPA or carbon filters can make them ineffective. If an air cleaner advertises a washable HEPA or carbon filter, look for another device.
Filter disinfection is not needed or recommended.
Surface Cleaning
The surfaces of a portable air cleaner should be vacuumed and cleaned every few weeks and after a poor air quality event. Unplug the air cleaner when cleaning. Wipe the air cleaner with a slightly damp cloth and use fragrance free soap or mild detergent. Always follow manufacturer recommendations to avoid shock hazards.
Pre-filter Maintenance
Pre-filters may be washable. Clean or vacuum washable pre-filters following the manufacturer’s instructions.
Carbon pre-filters
Some carbon filters are used as pre-filters. This means the air flows through the carbon filter first, then through the HEPA filter. In this case, it is especially important to replace the carbon filter according to the manufacturer’s recommendations.
Carbon filters should not be washed.
All Carbon Filters
All carbon filters need to be replaced to maintain their ability to filter gases. Vacuum or wipe a carbon filter to remove large particles.
Carbon filters should not be washed.
Other Ways to Improve Indoor Air
A portable air cleaner won’t remove all indoor air pollutants. It’s important to remove sources of contaminants and ventilate when outdoor air quality is good. See other ways to improve your indoor air quality.
More Resources
Choosing a Portable Air Cleaner
Ventilation and Air Quality for Reducing Transmission of Airborne Illnesses (PDF)
Guide to Air Cleaners in the Home, EPA
Air Cleaners for Asthma Programs, Regional Asthma Management and Prevention