Mitigating Wildfire Smoke in New and Old Residential Construction

Reading time: 8 mins

Wildfires have raged through forests and grasslands since the beginning of time; this includes most of the western portion of North America. These wildfires ravage the area annually, mostly from early June through October.

However, as climate change increasingly impacts our environments, wildfire seasons that were once 3—4 months long are quickly turning into semiannual and close-to annual events. In January 2022, Cecile Juliette, from the public information office of the California Department of Forestry and Fire protection said,

“We are towards the end of January. 10-15 years ago we use to call it the California fire season where we might get fires say in July that would last through maybe September or October.” Juliette went on to say, “So, it was just a few months. Now our fires are extending all the way through December and then into January. So it’s not really accurate
to call it a fire season.”

Residents in these impacted areas that are lucky enough to not have their home burnt to ashes still face a litany of problems. Billowing smoke can engulf nearby areas in just a matter of days, making it extremely hazardous for anyone to go outdoors in these conditions without an N95 mask or better.

For those in these impacted areas, the first course of action is always to check for air quality alerts from airnow.gov.

Air Quality

According to airnow.gov, there are six levels that are defined for air quality. The values on the air quality index (AQI) from the U.S. Environmental Protection Agency (EPA) are color-coded and range from 0-500.

The smoke that evaporates from a forest fire is known to be harmful to breathe. Wood smoke exhausts carbon monoxide, carbon dioxide, nitrogen oxide, and more. It is a well-known VOC (Volatile Organic Compound) that over a long period of time can cause detrimental side effects to one’s health.

It is important to note that anytime the AQI rises above 150 (red), the air is considered unhealthy for the general population. During a wildfire, the AQI can reach as high as 300 and higher. This means the concentration of air pollution particles in the air have reached over 15.5–30.4 parts per million (PPM) of carbon monoxide.

A Orange haze flooded the sky in NYC, 2023.

Smoke Rising in the East

According to reporting by Oliver Milman of 'The Guardian', in 2021, smoke from more than 80 major wildfires caused hazy skies and air quality to rise to hazardous levels in eastern American and Canadian cities such as Philadelphia, Washington DC, Pittsburgh, Toronto, and New York. At this time, the air quality rose above 150 in Manhattan, New York, which signaled an air quality alert that told most of the general population the current outdoor air may cause health risks for these individuals.

As recently as June 2023, according to nbcnewyork.com, state officials gave an air quality alert that rose above the ‘maroon’ level, which is the highest level on airnow.gov’s chart, with an AQI of 330. This meant everyone was more than likely affected by the smoke.

Additionally, according to an online calculator¹, over a 24-hour period, those living or visiting New York that breathed the air (during this air quality alert) breathed in the equivalent air pollution of more than 12 cigarettes (by the way, 12 cigarettes in the United States nearly equals an entire pack!).

Where Does the Smoke Originate?

The eastern smoke comes from United States’ northern neighbor, of which is home to some of the world’s densest forests that experiences wildfires every year. However, by June 2023, Canada already saw over 8,000,000 acres burnt; 13 times the previous 10-year average.

How Do Wildfires Commonly Start?

Most often, these wildfires start by either lightning or through human activity such as lighting firecrackers or from a discarded burning cigarette thrown in a vulnerable area. Additionally, the Washington Post reported that Canada faced 12.6°F higher temperature in May 2023 than in a typical May, and the entire Atlantic Region was heavily affected by droughts since February 2023. Both these factors made the area ripe for fires.

If My Area Is Under an Air Quality Alert, Is Staying Inside the Solution?

The experts at airnow.gov state that wildfire smoke can irritate an individual’s respiratory tract. They say the best way to protect yourself is by staying inside with all windows and outside doors closed shut, and to take other precautionary steps to limit exposure.

Precautionary Steps

If you must go outside, the EPA advises that you wear an N95 mask to protect against small, potentially harmful aerosols
Use an air purifier sized for the room that does not make ozone.
a. Using one with a HEPA filtration system is an even better course of action
Check your HVAC’s or fresh air appliance’s air filters and make sure they are up to date and of are high-quality
a. Run the air conditioning on a recirculation setting to prevent any outside air from coming in.
If driving, run the air on recirculation mode
a. Additionally, keep all windows closed to mitigate smoke from entering the vehicle.

How can Architects, Builders, and Engineers Help?

Because of modern building codes, new homes have been built to include improved insulation that creates tight, thermal envelopes. Therefore, they require mechanical ventilation so tenants can breathe fresh air. Directly introducing indoor air during cases of extremely high AQI is bound to cause health issues for some, if not most, individuals.

During periods of high AQI, homeowners can take emergency precautionary steps like keeping windows and outside doors shut and can run the forced air system on recirculation mode, but their designers can prepare them for wildfire smoke way before an alert is given.

Mitigating the Smoke Problem Before It’s a Problem with Whole-house Filtration

When an air quality alert is given, all ventilation should cease. The forced air system should be run on recirculation mode to keep the air moving. While the filter within the forced air system will stop large air particles from entering into the return air, without ventilation, the air will eventually become stale. Plus, without a carbon filter on the forced air system, any smoke and smells that enter the home will linger.

Therefore, if possible, we recommend installing a whole-house HEPA filtration system with a three-stage filtration system and an activated carbon filter onto the forced air system to filter the recirculated air. If recirculation is needed, the air stays fresher for a longer period of time. As a result of the activated carbon filter, it arrests odors like hydrogen sulfide (rotten eggs), cooking smells, and smoke.

If Whole-house Filtration Is Not an Option

If using a whole-house HEPA filtration system is not possible, we recommend using a portable HEPA filtration system. Like our HERO® HS300 HEPA system, it also uses a three-stage filtration system and an activated carbon filter as well. Additionally, it is not ducted, so the portable system can move to a “clean room” where clean air is needed the most.

The cabinet is insulated with ½" (12.5mm) high density expanded polystyrene to ensure minimal at best amounts of air leakage. The removable 5-foot (1.5 meter) cord and 3-prong plug allow for ease of use. Plus, the portable system only requires a 1-½ foot (.5 meter) space as well.

Conclusion

Wildfires these days are essentially all-over North America. Areas where wildfires have seemingly always been are now experiencing longer fire seasons and a large growth in the number of fires overall. There are a few reasons for this including hotter weather, drought, and homes being built in the WUI area. Areas that do not normally experience wildfires, such as the central and eastern parts of North America, have seen wildfires for all these same reasons as well.

Another factor with wildfires is the smoke that evaporates from the fire. Places that still do not see wildfires have a higher chance of being impacted by wildfire smoke, and largely, these places have no control over this problem. This includes the eastern areas of North America like Toronto and New York state.

Protecting yourself from the effects of wildfire smoke means taking preventative, common-sense measures such as wearing an N95 mask and turning your forced air system to recirculation mode.

If possible, we recommend adding a HEPA filtration system to the home’s forced air system to keep the air cleaner, longer. If adding a HEPA filtration system to a home is not possible, we recommend using a portable HEPA filtration system. This system also uses an activated carbon filter to capture smells that enter the space. It is also lightweight and can be used anywhere with a 3-prong outlet.

With these tips, you can keep yourself, your loved ones, and your clients breathing safer air during high AQI alerts.

¹The online calculator created by jasminedevv builds on ideas presented by Berkley researchers Richard A. Miller and Elizabeth A. Muller released in 2015. In their study, Miller and Muller calculated the amount of air pollution it takes to equal one cigarette’s worth of smoke.

Please Note: While Fantech's HEPA filtration systems can be beneficial, the best course of action is to consult a building professional to develop a plan and/or a system to mitigate wildfire smoke before it happens.

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