How Do You Filter Wildfire Smoke At Home?

Need to filter wildfire smoke in your home? Invest in an air purifier with HEPA filters, update your HVAC system with MERV 13 filters, or build a DIY air purfier at home. Here's how!

Worldwide, the area burned by wildfires each year has increased since the 1980s.

Increasing wildfires have severely affected air quality around the United States, especially in the Southwest to the Northwest regions. Wildfire smoke can travel thousands of miles, affecting people far from the fire's origin [1]. Filter wildfire smoke in your home by investing in a HEPA/carbon air purifier. Learn more about the health effects of wildfire smoke and how you can protect yourself.

Health Effects of Wildfire Smoke

Wildfires can spread quickly, and the health effects of inhaling smoke from them can cause immediate health reactions [2].

How wildfire smoke affects your body:

  • Coughing
  • Trouble breathing
  • Wheezing
  • Asthma attacks 
  • Headaches etc.

For many, these symptoms of wildfire smoke exposure can be temporary. However, the lasting effects of inhaling wildfire smoke have become a rising cause for concern. About 70,000 wildfires occur every year in the United States [3]. 

If you live in an area where wildfires are common, you could experience more serious long-term effects, such as:

  • Respiratory problems
  • Increased risk of:
    • Heart attacks
    • Stroke
    • Lung cancer
    • Decline in cognitive function

People with health conditions such as asthma, COPD, or heart disease are particularly sensitive to poor air quality. To protect yourself, consider using air purifiers at home to ensure you're breathing clean air.

How Does An Air Purifier Help with Smoke?

Air purifiers remove allergens and other harmful substances from the air as it circulates through them. Portable air purifiers are typically designed to filter the air in a single room. 

Depending on the size of your home, consider an air-purifying HVAC system for broader coverage. If this isn’t feasible, you can use portable air purifiers in the rooms where you spend the most time. 

There are various types of air filters, each designed to address different airborne pollutants. Since not all filters are effective against wildfire smoke, choosing a filter specifically designed to remove harmful substances found in smoke is important. 

Which Air Filter Is Best for Smoke?

There are many different types of filters on the market today. Some of the most common are mechanical filters (like HEPA filters) and carbon filters. 

Mechanical or HEPA filters physically remove particles from the air with a mesh screen. Carbon filters use carbon to absorb gasses and reduce odor. 

The best filter for wildfire smoke combines both HEPA and carbon filters. This combination effectively removes harmful particles from the air and helps minimize the smell of smoke, which can be quite irritating. [4]

If you have a central air system, such as an HVAC system, it's important to ensure it has a high-efficiency filter. Many homes are equipped with MERV 8 filters, but it's recommended to use filters labeled MERV 13 or higher for better performance. When shopping for replacement filters, look for those with a MERV rating of 13 or above to ensure optimal air quality. [5]

How to Build A Corsi-Rosenthal Box

The Corsi-Rosenthal Box is a DIY air purifier designed to improve indoor air quality by reducing virus-laden aerosol particles, wildfire smoke, pollen, and dust [6]. It is an effective and low-cost solution, especially relevant during the COVID-19 pandemic. 

The device consists of four MERV 13 filters, a box fan, and a piece of cardboard, all secured together with duct tape. The design allows for a high Clean Air Delivery Rate (CADR) by moving more air than typical HEPA air purifiers despite using less effective filters per pass.

To build a Corsi-Rosenthal Box, gather the necessary materials: four MERV 13 filters, a box fan, cardboard, and duct tape. Connect the filters to form a cube, ensuring the airflow arrows on the filters point inward. 

Use duct tape to seal all the seams between the filters to prevent air from bypassing the filter media. Next, place a piece of cardboard at the bottom of the cube and secure it with tape. 

Finally, position the box fan on top of the cube, with the airflow directed outwards, and tape it securely to prevent air leaks. Once assembled, the box can be plugged in to start purifying the air.

Which Air Purifier Is Best for Filtering Wildfires?

Wildfires can cause particulate matter to get into your air and your home. Particulate matter (PM2.5 and PM10) is one of the six principal air pollutants regulated by the EPA because of its risk to human health. [7] 

One of the main sources of these pollutants is from fire, including wildfires. This is why it is important when shopping for an air purifier that you purchase one with a mechanical filter like a HEPA filter. Only mechanical filters are able to physically filter out fine particles.  

If you are unsure about which portable air purifier to purchase, Million Marker has done the work for you. Check out Million Marker’s Amazon Shop for HEPA Air purifiers.

Additionally, you can purchase vacuum cleaners with HEPA filters to pick up particulate matter from smoke that has settled on surfaces in your home, like your carpet or furniture.  

How to Prepare for Wildfire Smoke In Your Home

Remember, while you may not be able to control what happens outside, you have the power to make your home a safe and healthy environment for yourself, your household, and your guests. 

Prepare your home for wildfire seasons by sealing your home. This includes sealing cracks and openings in walls to minimize outdoor air infiltration.

When wildfires are in the area, close all windows and doors. During this time, close any fresh air intakes from furnaces, fireplaces, or stoves. 

Remove Flammable Objects

Maintain a defensible space of at least 30 feet around your home by removing flammable objects such as lawn furniture, propane tanks, and wood piles. 

You never know when a wildfire might start. Clear leaves, pine needles, and other debris from roofs, gutters, decks, and patios regularly.

You might have to make some adjustments to your lawn care routine. Replace flammable mulch and vegetation within 5 feet of the home with nonflammable materials. Trim tree branches to ensure they are at least 10 feet away from the roof and chimney to prevent fire spread.

Don’t make it easier for wildfires to spread. Store flammable liquids and equipment, like lawnmowers and gas cans, away from the house. These items should be stored at least 30 feet away from your home.

Reinforce the House

Fires in the United States caused over $18 billion in property loss in 2022 alone. Protect your property by reinforcing your home [8]. 

Instead of wood or shingles, use fire-resistant materials for roofing. Fire-resistant roof materials include metal, clay, or tile.

Install dual-paned windows with at least one tempered glass layer to withstand heat and prevent breakage.

Lastly, cover vents with 1/16-inch to 1/8-inch noncombustible metal mesh to block embers.

Chimney and Flue Maintenance

Prevent outdoor air polluted by wildfire smoke from entering your home. Install a non-flammable screen over the chimney to prevent embers from entering. Close the fireplace flue during wildfire season when not in use.

Be Ready to Evacuate

Be alert to wildfire threats in your area. Have an escape plan for family and pets ready if a pre-evacuation notice or evacuation order is issued for your neighborhood.

Before evacuating from a wildfire, close all windows, doors, and vents to prevent smoke and embers from entering. Cover windows and vents with plywood if time permits to provide additional protection.

Ensure all garden hoses are connected and ready for use, and fill buckets with water for firefighters. Keep all exterior doors and gates unlocked to allow firefighters easy access.

Why Are Wildfires So Common?

Wildfires occur naturally and play an important role in the health of the ecosystem. For example, some pine trees require fire to release their seeds. However, wildfires can also be caused by human negligence, such as improperly extinguished cigarettes or bonfires. 

Decades of fire suppression have resulted in denser forests, more undergrowth, and an accumulation of fuel. This buildup can lead to larger wildfires. Additionally, in recent years, climate change has made wildfires more frequent. Rising temperatures and prolonged droughts contribute to this increase in wildfire occurrence.

Human-caused wildfires not only pose significant risks to human health and the environment but also create a costly burden on society through property damage and disruption of livelihoods. Moreover, wildfires release large amounts of carbon into the atmosphere, further contributing to climate change.

Where Are Wildfires Most Common?

Wildfires are significantly more common in the Western United States than in the East, particularly during the summer months. This region experiences more frequent drought conditions, which makes it more susceptible to wildfires. 

From 2003 to 2021, compared to 1984 to 2002, the western part of the United States has seen increases in areas burned due to wildfires in all months of the year, with significant increases in the summer months. The eastern part of the United States did not see a jump in wildfires in the summer and remained about the same from 1984 to 2021. 9]

Are P100 Filters Good for Wildfire Smoke?

Obviously, we cannot stay inside forever! So, if wildfire smoke is a concern, make sure to wear a respirator mask. 

Respirators protect against fine particulate matter. When looking for a respirator mask, look for N95, KN95, or P100 respirators [10]. 

Is P100 Better Than N95 for Smoke from Wildfires?

Any mask for wildfires is better than none at all. However, P100 respirators are slightly superior to N95. 

N95 Respirators filter out 95% of airborne particles. They are constructed to block dust, pollen, and smaller particles like bacteria or viruses.  

P100 Respirators filter out 99.97% of airborne particles. They are constructed to block out dust, pollen, bacteria, viruses, but also hazardous substances like lead, asbestos, and mold. 

P100 is used in industrial settings when hazardous substance exposures are more likely to occur. Both N95 and P100 masks are designed to filter out particles that are 0.3 microns in size or larger. 

Since particulate matter is the main concern in wildfire exposure, both these masks are suitable to help protect against smoke. Additionally, while P100 may offer some better protection, they are often more costly and harder to find in retail stores.[11]

Wildfire occurrences may be out of your control, but protecting your health is not! Remember these important tips if you experience wildfires near your community to help prevent these health concerns. Making small changes and wearing a mask when necessary can make a big difference in keeping yourself safe from wildfire smoke. 

How Can We Improve Air Quality During Wildfires?

Clean air is crucial, whether it’s indoors or outdoors. Use a HEPA air purifier in your home to effectively filter out fine particles from smoke, while sealing windows and doors helps prevent smoke from entering. When you need to be outside, wearing a P100 or N95 respirator mask will protect your lungs from harmful particles. Additionally, stay informed about air quality levels through local news or apps, limit outdoor activities during peak smoke times, and keep emergency supplies, including masks and air purifiers, readily available. By taking these precautions, you can significantly reduce your exposure to harmful wildfire smoke and safeguard your health.

Resources

[1] https://www.epa.gov/climate-indicators/climate-change-indicators-wildfires 
[2] https://www.cdc.gov/wildfires/risk-factors/index.html 
[3] https://sgp.fas.org/crs/misc/IF10244.pdf
[4] https://www.consumerreports.org/appliances/air-purifiers/buying-guide/ 
[5] https://www.consumerreports.org/appliances/air-purifiers/best-air-purifiers-for-wildfire-smoke-a1153295134/ 
[6] https://engineering.ucdavis.edu/news/science-action-how-build-corsi-rosenthal-box
[7] https://www.epa.gov/criteria-air-pollutants/naaqs-table
[8] https://www.statista.com/statistics/203776/property-loss-in-the-us-due-to-fires/ 
[9] https://www.epa.gov/climate-indicators/climate-change-indicators-wildfires 
[10] https://myhealth.alberta.ca/Alberta/Pages/wildfire-smoke-health.asp
[11] https://www.armbrustusa.com/blogs/news/is-p100-better-than-n95