1. Lock out smoke
- Close doors and windows.
- Seal off any gaps that might be letting in outdoor air (use tape, rolled towels or weatherization plastic).
- An indoor air quality monitor can help you understand how much smoke may be entering your living space. This can help inform when to increase air filtration or find cleaner air. For more information see the EPA’s Low-Cost Air Pollution Monitors.
**If your home is too warm to stay inside with the windows closed, or you are at-risk of smoke-related health effects, you should seek shelter elsewhere.**
2. Filter the air
- Purchase or make an air cleaner.
- Filter the air using an air cleaner.
- Set AC/furnace to fan/recirculate mode and make sure the filter is clean.
- If traveling in a car, set the AC to recirculate (usually identified by a car symbol with a U-turn arrow inside).
- Limit exhaust fan use unless you are cooking.
3. Make a clean air room
- Choose an interior room with few windows and doors that all family members can fit in.
- Keep windows and doors closed.
- Use an air cleaner to help remove harmful particles from the air.
- For additional information, see the EPA’s tips to create a clean room.
4. Avoid activities that create more indoor pollution
- Do not burn anything, including candles, incense, cigarettes or gas stoves.
- Avoid frying or broiling when cooking.
- Postpone using a vacuum or sweeping. A HEPA vacuum is OK.
5. Use an air cleaner
To help filter air in a room, buy or make an air cleaner. You may also see them called air purifiers.
Air cleaners pull in dirty air, trap tiny harmful particles and blow out cleaner air. An air cleaner can help everyone breathe cleaner air inside. It is especially helpful for babies, the elderly, pregnant people, and people with asthma, allergies or other breathing difficulties.
You can buy one, make your own or talk to your health insurance provider to get one.
If you have an HVAC system, we recommend also using a portable air cleaner when the air is smoky. Your HVAC may have a filter designed to remove larger particles, like pet hair or dust. But it may not filter the smaller harmful particles found in wildfire smoke.
Choosing an air cleaner
A good resource to start with is Energy Trust, which offers deals on air cleaners across a range of options.
There are many portable air cleaner options, which can be overwhelming! They can range from $30-$500. Multnomah County does not certify or recommend specific brands or devices, but there are many options across this price range that will work.
To help guide which one you should use, think about these important factors:
- Cost: Consider the cost of the unit and replacement filters. You'll want at least one extra filter on hand at all times.
- A true HEPA filter: Look for a filter that removes particles down to 0.3 microns or smaller.
- Room size: Your unit needs to be able to clean the whole room. Calculate the square footage of the room you spend the most time. Do this by measuring the length and width wall-to-wall in feet and multiplying those two numbers. Compare that total to the device’s reported capacity. If you end up with an undersized air cleaner, it will leave indoor air pollutants.
- No ozone production: Some air cleaners produce ozone, which is a pollutant harmful to human health. The California Air Resources Board (CARB) has a list of approved certified air cleaning devices. Check the list to make sure the unit you are interested in has been approved by CARB. Also make sure it is listed as mechanical. Units indicated as electric produce ozone.
- Energy Star rating: These will be the most energy efficient and cost less to run.
- Noise levels: The air cleaner will be most effective on its highest setting, which is usually the noisiest. Some models are quieter than others.
- Scent diffuser: Avoid using scent diffusers as they can add additional pollutants in your indoor air.
You can also refer to the EPA's guide to home air filters.
Air cleaner tips
- Use an air cleaner in the room you spend the most time in.
- Close all windows and doors in the room while the air cleaner is in use.
- Clean the prefilter monthly with a brush or vacuum.
- Replace the filter when it looks dirty/brown.
- The highest airflow setting is the most effective, and should be used during high-pollution events.
Do-It-Yourself air cleaner
You can assemble a DIY air cleaner for $30-50 if you need an air cleaner on short-notice. You will need:
- A box fan
- A 20” x 20” furnace filter, ideally rated MERV 13-16 (or FPR 10 or MPR 1500-1900) or higher
- Tape (painter or duct) or bungee cord
Tape or bungee the filter to the back of the fan. Make sure the arrows on the filter point towards the front of the fan.
Plug in the fan and turn it on. Do not leave the unit unattended.