How to Create a Clean-Air Room

What a clean-air room is

A clean-air room is one room arranged to keep wildfire smoke particles lower than they are outdoors and, ideally, lower than they are in the rest of the home. It gives the household a place to sleep, rest, work, or play while outdoor air is unhealthy.

The goal is exposure reduction, not a perfectly sealed room. Smoke can enter through open doors, leaky windows, ventilation systems, and small gaps. A closed room with continuous filtration can still make a meaningful difference.

Choose the room before smoke arrives

Select a room that can be closed off, cooled, and used comfortably for many hours. A bedroom with an attached bathroom can work well. Avoid a room with a fireplace, a frequently opened exterior door, or cooking equipment.

• Make sure everyone who may use the room can fit safely.
• Keep medication, water, phone chargers, activities for children, and pet supplies nearby.
• Keep doors and walkways clear so the household can evacuate quickly.
• Plan for people with mobility, medical, sensory, or caregiving needs.

Limit smoke entering the room

Close windows and exterior doors. If your air conditioner or HVAC system has an outside-air setting, turn it off and use recirculation when the equipment allows. Avoid running exhaust fans longer than necessary because they can pull replacement air through leaks elsewhere in the home.

Weather stripping or removable draft blockers may reduce obvious leaks, but do not permanently block exits or ventilation needed for combustion appliances. Never use fuel-burning generators, grills, camp stoves, or heaters indoors or near windows.

Use filtration that matches the space

A portable air cleaner should be sized for the room. Look for a smoke or particle clean-air delivery rate appropriate for the room area and run the unit continuously on the highest tolerable setting. Choose a device that does not intentionally generate ozone.

For central HVAC, EPA recommends considering a MERV 13 or higher filter when the system is compatible. A restrictive filter can reduce airflow in some systems, so check the equipment manual or ask a qualified technician. During heavy smoke, inspect and replace filters more frequently.

DIY air cleaners

A DIY cleaner combines a newer box fan with one or more high-efficiency furnace filters. It can be a temporary option when a commercial purifier is unavailable or unaffordable. Use a fan manufactured in 2012 or later with a recognized safety mark, follow the fan instructions, keep children supervised, and do not use damaged cords or an unsafe extension setup.

More filter surface area generally improves airflow and filtration. Align filter arrows with the direction of airflow and seal gaps around the filter. A DIY unit is not a permanent substitute for equipment of known performance, but research cited by EPA indicates that well-built units can reduce smoke particles.

Avoid making indoor air worse

During a smoke event, indoor sources matter more because the home is closed. Avoid smoking or vaping, candles, incense, wood fires, aerosol sprays, frying, broiling, and vacuuming without HEPA filtration. Use damp dusting or mopping to keep settled particles from becoming airborne.

Balance smoke protection with heat safety

Wildfires and smoke often occur during extreme heat. A closed room that cannot be cooled may become dangerous. If the room is too hot, electricity fails, smoke continues to enter, or someone develops worsening symptoms, relocate to a cleaner-air building, cooling center, family home, or other safe location.

Use the room effectively

Spend as much time as practical in the cleaner space when air quality is poor. Keep physical activity gentle because heavier breathing increases the amount of pollution inhaled. When outdoor air improves, use that opportunity to ventilate the home if temperatures and local conditions make it safe.

When medical help is needed

Move to cleaner air if anyone develops coughing, wheezing, chest discomfort, headache, dizziness, or shortness of breath. Follow asthma or other medical action plans. Call 911 for severe trouble breathing, chest pain, fainting, confusion, or blue or gray lips or face.