There are a lot of choices when purchasing a portable air cleaner. It is important to choose a portable air cleaner that will be effective and won’t add other pollutants to indoor air. DOH recommends choosing an air cleaner that has:
- Filters only – avoid ionizer, ozone, or ultraviolet (UV) technologies
- A high efficiency particulate air (HEPA) filter
- An effective clean air delivery rate (CADR) for your room size
- Low noise
It can be difficult to find product information when comparing portable air cleaners. You may need to contact the manufacturer.
Example Portable Air Cleaners Meeting DOH Recommendations
We have developed a list of portable air cleaners to help people and organizations choose the best portable air cleaner option. The portable air cleaners on this list have been reviewed by air quality experts and meet DOH health recommendations.
Be sure to consider an air cleaner with the appropriate CADR for your room size. The list also includes details like how loud an air cleaner is and how much replacement filters cost.
View the List of Example Portable Air Cleaners Meeting DOH Recommendations – PDF
Note: The portable air cleaners included in the list are not endorsed or guaranteed by Washington DOH. The list does not include every portable air cleaner meeting DOH recommendations. This is a working document, last updated December 2025. Please check the manufacturer’s website for the most current information. DOH is not responsible for the performance, safety, or availability of any products listed.
What to Look for When Choosing a Portable Air Cleaner
1. Filters only – avoid ionizer, ozone, or UV technologies
Choose a mechanical air cleaner that uses filters and no other technologies.
"Mechanical" portable air cleaners only use physical filtration, such as pleated or HEPA filters. Mechanical portable air cleaners with a HEPA filter are highly effective at removing indoor air contaminants.
Despite their growing popularity, “electronic” air cleaners use other technologies that produce harmful byproducts like ozone, hydroxyl radicals, formaldehyde, and ultrafine particles. These contaminants have been linked to adverse health effects like worsening of asthma symptoms, lung inflammation, increased blood pressure, and increased risk of cancer.
Look for the following:
- An air cleaner that says “mechanical” and not “electronic” on the list of California Air Resources Board (CARB)-certified air cleaning devices.
- Check the manufacturer’s website or the air cleaner’s manual to see if other technologies are used.
Avoid the following:
- Ozone generation
- Ionization
- Ion generation
- Plasma technology
- Ultraviolet (UV) light
- Germicidal or disinfection technology
- Essential oil diffusers
- Electrostatic precipitation
- Photocatalytic oxidation
Optional pre-filters and carbon filters
Most portable air cleaners have a main HEPA filter that removes particles like dust, pollen, and smoke. Some air cleaners also have a carbon filter or a pre-filter. Pre-filters help extend the life of the HEPA filter and remove large dust. Carbon filters remove some gases like volatile organic compounds (VOCs) but generally need to be replaced frequently.
Pre-filters and carbon filters are beneficial but should not replace a HEPA filter.
Can filters 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. However, you can use a slightly damp cloth or vacuum to remove large debris from the outer surface of the filter.
Pre-filters may be washable. Follow manufacturer recommendations for regular cleaning.
2. HEPA Filter
Choose an air cleaner with a HEPA filter.
Not all pleated filters are HEPA filters. A HEPA filter effectively removes 99.97% of particles that are 0.3 micrometers in size. These fine particles can get deep into the lungs.
Particles smaller and larger than 0.3 micrometers are removed by a HEPA filter with even higher efficiency.
Look for the following:
- Technical specifications should say if a HEPA filter is used
- Ask the manufacturer
Avoid the following:
- “HEPA-like" filter
- “HEPA-style” filter
- “99% HEPA” filter
- No mention of a HEPA filter
- A HEPA or carbon filter advertised as "washable".
3. Effective Clean Air Delivery Rate (CADR) for your room size
Look for an air cleaner that lists a “tobacco smoke” or “smoke” CADR. The CADR shows how well a portable air cleaner removes particles from the air. The smoke CADR specifically considers small particles that can get deep into the lungs.
The CADR is the volume of air a portable air cleaner can filter in a minute when it’s set at maximum fan speed. The higher the CADR, the faster and more effectively the air cleaner filters.
The CADR is measured in cubic feet per minute (CFM)—not in square feet or room area. If an air cleaner only lists coverage in square feet, or the manufacturer cannot provide the smoke CADR, look for another device.
Other than smoke, CADRs may be measured for pollen, dust, or non-specific particles. These other types of particles are larger than smoke particles. It is best to consider the smoke CADR.
How to find the right smoke CADR for your room size
First, measure your room.
Measure the length and width of your room in feet. Then, multiply those two numbers together. The result is the room area, in square feet.
Example: If your room is 20 feet long and 20 feet wide, multiply 20 and 20, which equals 400 square feet.
Second, compare your room size with the air cleaner’s smoke CADR
An effective portable air cleaner’s smoke CADR should be equal to at least 2/3 of the area of the room.
Example: If the area of your room is 400 square feet, choose a portable air cleaner with a smoke CADR of at least 267 CFM because 2/3 of 400 is 267.
Refer to the table below or use the calculator tool at the bottom of this webpage to calculate the smoke CADR needed for your room.
Room Size and Smoke CADR Comparison Table
| Room Area (square feet, assuming an 8-foot ceiling) | 200 | 300 | 400 | 500 | 600 |
| Approximate CADR (CFM) | 133 | 200 | 267 | 333 | 400 |
How the CADR value recommendation is calculated
A portable air cleaner with a CADR of 2/3 the area of a room should clean the room air 5 times per hour, assuming the room’s ceiling is 8 feet high. A portable air cleaner with a CADR equal to the room area should clean the room air 7.5 times per hour, assuming the room’s ceiling is 8 feet high.
CADR test standards
If you or your organization is buying multiple air cleaners, you may want to check that the smoke CADR was measured following a reputable procedure. The CADR standard was developed by the Association for Home Appliance Manufacturers (AHAM). Air cleaners tested using the AHAM’s CADR procedure are marked “AHAM Verifide”. If a device lists a smoke CADR but does not say “AHAM Verifide”, it is possible the CADR was measured following another reputable procedure. Ask the manufacturer how the CADR was measured.
Additional considerations
- Areas with frequent wildfire smoke
- If you’re in an area that often has heavy wildfire smoke, consider a portable air cleaner with a higher smoke CADR.
- Example: If the area of your room is 400 square feet, but you live in an area with heavy wildfire smoke, consider an air cleaner with a smoke CADR closer to 400 CFM.
- If you’re in an area that often has heavy wildfire smoke, consider a portable air cleaner with a higher smoke CADR.
- Large or open rooms
- If your room has a ceiling taller than 8 feet, if you have an open floor plan, or if doors are kept open between rooms, consider the following:
- Use multiple portable air cleaners, Keep noise levels in mind.
- Find a portable air cleaner with a higher smoke CADR.
- Create a cleaner air room using guidance from the Environmental Protection Agency (EPA).
- If your room has a ceiling taller than 8 feet, if you have an open floor plan, or if doors are kept open between rooms, consider the following:
- Cost
- Portable air cleaners with high smoke CADRs may be expensive. Choosing an air cleaner with a low smoke CADR is better than not having one during a poor air quality event.
- Portable air cleaners with high smoke CADRs may be expensive. Choosing an air cleaner with a low smoke CADR is better than not having one during a poor air quality event.
4. Low Noise
Look for the air cleaner’s noise level at the highest fan speed. If this isn’t clear, check with the manufacturer. Loud devices could be harmful or more likely to be turned off.
The EPA recommends keeping indoor noise levels below 45 decibels (dB). For reference, 40 dB is roughly the noise level of a humming refrigerator. The noise level of a leaf blower is about 80 dB. You can use the Sound Level Meter App from the Center for Disease Control (CDC) or a similar app on a smart phone to measure noise levels.
If an air cleaner is too loud at a high fan speed, consider using multiple air cleaners around the room and operate them at a lower fan speed.
An air cleaner with an “auto” setting uses an air pollution sensor to automatically adjust the fan speed. This feature can help reduce noise by only allowing high fan speeds when needed most. An “auto” setting based on a particulate matter (PM) sensor is best.
Other Considerations
- Upkeep and cost
- HEPA filters need to be replaced regularly, so check the cost and frequency for replacements. Typical costs are $40-100 per replacement, depending on the air cleaner’s size and filter type. Suggested replacements are often every 3 to 12 months and following heavy smoke events. Some devices may have multiple filters to replace. A separate, washable or vacuumable pre-filter can improve the lifetime of the HEPA filter.
- Energy
- Check the Energy Star database, U.S. Department of Energy for more energy efficient devices, especially for large facilities using multiple devices.
- Tampering
- Some devices provide a “child lock” feature that restricts button use.
- Footprint
- Some portable air cleaners are large or heavy. Before purchasing a device, consider the space it will take up.
- Air sensor
- Some air cleaners have an “auto” setting, which uses a sensor to automatically adjust the fan speed. An “auto” setting based on a PM sensor is best.
- Display
- A display that can be turned off may be helpful at night.
Making your own box fan filter can be a budget-friendly option to filter air and improve indoor air quality in a single room or designated space. See the BC Centre for Disease Controls’ factsheet on Do-It-Yourself Air Cleaners (PDF).
Spaces Other Than Your Home
There are additional considerations when choosing an air cleaner for spaces like schools, childcare facilities, adult care facilities, or offices. Be sure to check noise requirements for these spaces. Upgrading building ventilation systems should be the first priority. Check these resources for more information:
- Improving Ventilation and Indoor Air Quality During Wildfire Smoke Events - Recommendations for Schools and Buildings with Mechanical Ventilation (PDF)
- Ventilation and Air Quality for Reducing Transmission of Airborne Illnesses (PDF)
Other Ways to Improve Indoor Air
A portable air cleaner won’t remove all indoor air pollutants. It’s important to remove sources of pollutants and ventilate when outdoor air quality is good. See other ways to improve your indoor air quality.
More Information
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