Cleaner Indoor Air During Smoke Season

Wildfire smoke can roll into Reno fast, turning bluebird mornings into hazy afternoons. If you live in Washoe County, including neighborhoods like St. James Village, you know smoke season is part of life. You want to protect your household and keep your home comfortable, especially if you have sensitive family members or upcoming showings. In this guide, you’ll learn how to set up a clean-air room, pick the right filters or portable cleaners, and time ventilation using trusted local tools. Let’s dive in.

Know your AQI and risk

Air quality in our region can swing from Good to Hazardous during wildfire season. The U.S. Air Quality Index (AQI) categories help you decide when to act: Good (0–50), Moderate (51–100), Unhealthy for Sensitive Groups (101–150), Unhealthy (151–200), Very Unhealthy (201–300), and Hazardous (301+). When AQI reaches Unhealthy for Sensitive Groups, start protective steps, especially for vulnerable people.

Sensitive groups include older adults, young children, pregnant people, and anyone with asthma, COPD, heart disease, or similar conditions. Outdoor workers and pets can also be affected by smoke. Review health-based guidance on the AirNow AQI map and wildfire smoke page to understand what each category means for your day.

Monitor Reno air quality in real time

You’ll make better decisions when you check a few reliable sources together:

• AirNow for official AQI and forecasts. Use it for health guidance tied to the AQI categories. Start here: AirNow official AQI and guidance.
• PurpleAir for neighborhood-level, near real-time PM2.5 sensors. These can read higher than government monitors but are great for spotting local changes. Check the map near your home: PurpleAir sensor map.
• Washoe County Health District for local advisories and public health updates: Washoe County Health District.
• National Weather Service Reno for wind shifts that move smoke in or out: NWS Reno forecast office.
• Nevada Division of Environmental Protection for state monitoring context: Nevada air quality resources.

Set alerts on the AirNow app, monitor a PurpleAir sensor near your block, and sign up for county notifications. When AQI trends worsen, you can act quickly.

Build a clean-air room

A clean-air room gives you a place with the lowest possible smoke particles during bad air.

Pick the right room

Choose an interior space with few exterior walls and windows, like an interior bedroom or a living room away from exterior doors. Avoid rooms with combustion sources, such as a kitchen with a gas stove or a fireplace.

Seal and prep

• Close all windows and exterior doors. Add basic weatherstripping if you have it.
• Block gaps under doors with a draft stopper or a rolled towel.
• Temporarily seal large cracks at window frames with painter’s tape or removable foam.
• Reduce indoor particle sources. Skip vacuuming, avoid frying or high-heat cooking, and do not burn candles or incense.
• If possible, remove dust-collecting fabric items like heavy curtains and extra rugs.

Filter and circulate

• Run a portable HEPA air cleaner that is sized correctly for the room (see sizing below). Place it so air flows across the part of the room you use most.
• If your central HVAC can support a higher-efficiency filter (MERV 13 or higher), run the fan on ON or continuous to recirculate and filter air for the whole home. Combine the HVAC filtration with the portable HEPA to lower levels further in your clean room.

Use and duration

Close the door and use the clean-air room for sleeping and time with vulnerable family members when AQI is Unhealthy or worse. Keep it running continuously while outdoor air is poor.

Choose the right filter or cleaner

HVAC filters and MERV ratings

• Aim for MERV 13 as a practical minimum for capturing smoke-sized particles (PM2.5). Higher MERV captures more but can reduce airflow.
• Not every system can handle high-MERV long term. Check your equipment or talk with an HVAC professional before making a permanent switch.
• During smoke events, run the fan continuously if the system and filter allow it, and change filters more often. A loaded filter does less work.

Portable HEPA air cleaners

• Look for true HEPA. These remove at least 99.97% of particles down to 0.3 microns.
• Focus on CADR (Clean Air Delivery Rate) for smoke. CADR tells you how much clean air the unit delivers per minute.
• You may need to run the unit on a higher speed for best results during heavy smoke. Balance noise with performance.

DIY box fan with filter

• A box fan paired with MERV 13 or MERV 11 filters, often called a Corsi-Rosenthal design, can cut indoor PM2.5 significantly for a low cost.
• Use a fan with a fused plug, place it securely, and avoid wet areas. This option is effective but less convenient than certified HEPA units.

Note: HEPA addresses particles, not gases. If smoke odor bothers you, consider a HEPA unit with an activated carbon stage for odor adsorption.

Size it right with simple math

Use CADR to match a device to your space.

• Room volume = length × width × height
• Required CADR (CFM) = room volume × desired ACH ÷ 60
• ACH stands for air changes per hour. During smoke episodes, aim for 4 to 6 ACH or higher for faster reduction.

Example: A 12 ft × 12 ft × 8 ft bedroom is 1,152 cubic feet. For 5 ACH, you need about 96 CFM of clean air (1,152 × 5 ÷ 60 ≈ 96). Choose a cleaner with a smoke CADR at or above that number. If one unit cannot reach the target, use two devices or pair a portable HEPA with your HVAC filtration.

Run the cleaner at least 30 to 60 minutes before using the room, and keep it on while AQI is above Moderate.

Ventilate at the right time

When outdoor smoke is present, keep windows closed and rely on filtration. Only ventilate when outdoor air is cleaner than indoors, ideally when AQI is Good (0–50). Use AirNow for official AQI and NWS Reno forecasts to see when winds may shift.

Sometimes AQI improves overnight. Verify with a nearby PurpleAir map sensor and AirNow. If both show cleaner air, open windows briefly to flush the home, then close up and return to filtration. When regional smoke clears and AQI returns to Good, open windows wider and run fans to air out residual odors.

Smart habits during smoke days

• Limit strenuous outdoor activity when AQI is Unhealthy or worse.
• If you must be outside in heavy smoke, wear a NIOSH-certified N95 or KN95 respirator. Cloth masks do not filter PM2.5 well.
• Avoid indoor combustion. Skip candles and wood-burning. Cook simple meals or use electric appliances with lids to reduce emissions.
• If you have to cook on a stove, use an exhaust vent that sends air outdoors only when the outdoor air is cleaner than indoors.
• Watch pets for coughing or lethargy and limit their outdoor time.

For general health information, review CDC wildfire smoke guidance and EPA wildfire smoke and indoor air tips.

After the smoke clears

• Replace or clean filters in both portable units and HVAC according to manufacturer guidance. Heavily loaded filters lose effectiveness.
• Wipe surfaces with a damp cloth to remove settled particles and reduce resuspension.
• If you use indoor sensors, take a reading before and after filter changes to confirm improvements.
• Plan ahead for the next event. Stock replacement filters and confirm your clean-air room setup.

Smoke season checklist for Reno homes

• Sign up for AirNow and Washoe County alerts; check a nearby PurpleAir sensor.
• Choose an interior clean-air room. Seal gaps and remove dust-collecting fabrics if possible.
• Run a correctly sized portable HEPA cleaner continuously during smoke days.
• If your HVAC supports it, install a MERV 13 filter and run the fan continuously.
• Avoid indoor combustion and high-smoke cooking. Wear an N95 if you must go outside when AQI is high.
• Replace filters and air out the home once AQI returns to Good.

Final thoughts and local support

Smoke season does not have to derail your routine or your real estate plans. With a ready clean-air room, the right filters, and smart ventilation timing, you can keep indoor air healthier for your household and create a more comfortable experience for guests and potential buyers.

If you are preparing to buy or sell in Reno or nearby communities like St. James Village, a simple air strategy helps your home feel fresh during showings and move-in. Ready to plan next steps? Connect with Unknown Company to request a personalized home valuation.

FAQs

When should Reno residents start smoke protections?

• Begin protective actions when AQI reaches Unhealthy for Sensitive Groups (101+), and act promptly at Unhealthy (151+), especially for vulnerable people.

Can my central AC handle smoke on its own?

• A central system with a MERV 13+ filter running continuously helps the whole house, but a portable HEPA unit in a clean-air room gives the best targeted protection.

What is better: HEPA or a higher-MERV furnace filter?

• They do different jobs. Use a high-MERV HVAC filter for whole-home reduction and a portable HEPA to create a low-particle zone where you spend time.

Are DIY box-fan filters effective and safe?

• Yes, when built and used properly. Use a fan with a fused plug, place it securely, and avoid leaving it unattended for long periods without checks.

When is it safe to open windows after a smoke event?

• Ventilate when outdoor AQI is Good (0–50) or clearly cleaner than indoors. Confirm using AirNow and a nearby PurpleAir sensor before opening windows.