Wildfire Smoke and Air Quality Preparation for Apartment Renters
Wildfire smoke and air quality preparation for apartment renters matters even if you live hundreds of miles from a fire line. Smoke travels for days and settles over cities, and in a small apartment with shared ventilation you cannot simply open a window to clear the air. The goal is to keep the bad air out and create one clean room to breathe in.
Understand what you are breathing
Wildfire smoke is a mix of fine particles, called PM2.5, plus gases. The particles are tiny enough to pass deep into your lungs and even your blood. The Air Quality Index, or AQI, is the standard way to track how bad the air is on any given day.
| AQI range | Level | What to do |
|---|---|---|
| 0 to 50 | Good | Normal activity |
| 51 to 100 | Moderate | Sensitive groups limit long exertion outside |
| 101 to 150 | Unhealthy for sensitive groups | Move activities indoors |
| 151 to 200 | Unhealthy | Everyone limits outdoor time |
| 201 to 300 | Very unhealthy | Stay inside, seal your home |
| 301 and up | Hazardous | Full shelter, avoid all outdoor air |
Seal your apartment before smoke arrives
The best time to seal your apartment is before the air turns bad. Once smoke is inside, it is hard to remove. A few dollars of weather stripping and tape close the gaps that let smoke in.
- Apply weather stripping around windows and exterior doors
- Seal gaps around window air conditioners with foam or tape
- Close the fresh air intake on any HVAC or wall unit
- Roll towels under doors that open to hallways or outside
Build one clean air room
You do not need to clean the air in your whole apartment. Pick one room, usually a bedroom, and make it your clean air room. Run a portable HEPA air purifier sized for that room and keep the door closed.
- Choose a room with no windows if possible, or the fewest windows
- Pick a purifier with a true HEPA filter rated for the rooms square footage
- Run it on the highest setting when the AQI is bad
- Keep extra HEPA filters on hand, they clog faster during smoke events
A budget option: the box fan filter
If you cannot find or afford a HEPA purifier, you can build a simple filter fan that researchers and public health agencies have studied. It uses a standard box fan and a MERV 13 furnace filter to clean a surprising amount of smoke from a room.
- 1Buy a 20 inch box fan and a 20 inch MERV 13 furnace filter
- 2Tape the filter to the back, the side that pulls air in, with the arrow pointing toward the fan
- 3Run it in your clean air room with the door closed
- 4Replace the filter when it looks gray or airflow drops
Protect yourself when you must go out
Sometimes you have to go outside during a smoke event, for work, errands, or an evacuation. A proper mask makes a real difference, but only the right kind works.
- Use a well fitting N95 or KN95 mask, cloth and surgical masks do not filter fine particles
- Keep several masks in a drawer so you always have one ready
- Limit outdoor exertion, breathing hard pulls more smoke deep into your lungs
- Change clothes when you come back in to avoid bringing particles inside
If smoke is paired with an evacuation order, read our apartment evacuation plan for renters without a car.
Frequently asked questions
Editorial note: this guide provides general preparedness information, not emergency, medical, legal, or engineering advice. Recommendations are cross-checked against public emergency-management guidance and adapted for small-space living. During an active emergency, follow your local authorities and emergency services. See our editorial standards and affiliate disclosure.
