Here Are The Gadgets I Use to Protect My Family from Deadly Wildfire Smoke

Image: Anass Bachar/EyeEm/Getty Images

If you live on America’s West Coast, you’ve probably bookmarked the air quality monitoring website PurpleAir by now. I live in the San Francisco Bay Area, where drifting smoke from historic wildfires has turned the sky orange, shuttered national parks and other outdoor spaces, and intermittently made our air quality the worst in the world.

Wildfire smoke isn’t just a nuisance, either it’s a killer. As the San Francisco Chronicle reports, smoke from 2020’s wildfires has likely already killed 1,200 to 3,000 people. That’s orders of magnitude more than have died in the fires themselves. The World Health Organization says that air pollution cost 4.2 million lives worldwide in 2016 alone.

While it “can make anyone sick,” the CDC says, wildfire smoke is especially harmful to people with conditions like asthma or heart disease, as well as children, pregnant women, and first responders. It can even potentially exacerbate symptoms of Covid-19. Even if the smoke doesn’t directly sicken you, it may lower your productivity or cause physical stress (more on that below).

According to National Geographic, climate change, forestry management practices, droughts, and a variety of other factors mean that devastating fires are here to stay. Faced with a major yearly fire season and knowing the dangers of wildfire smoke, I wanted to find out how to keep my family safe. As a Californian and a technologist, I decided to find out what gadgets and technologies could help me reduce air pollution in my home.

As the San Francisco Chronicle reports, smoke from 2020’s wildfires has likely already killed 1,200 to 3,000 people. That’s orders of magnitude more than have died in the fires themselves.

According to the CDC, wildfire smoke is “a mix of gases and fine particles from burning trees and plants, buildings, and other material.” The smoke is harmful largely because it contains fine particulate matter. The Environmental Protection Agency (EPA) says that “fine inhalable particles” — those that are smaller than 2.5 microns, or 30 times smaller than the diameter of a human hair — “can get deep into your lungs and some may even get into your bloodstream,” posing “the greatest risk to health.”

You may have seen these particles referred to as PM2.5. They’re often used to calculate an Air Quality Index (AQI) between 1 and 500, which indicates how unhealthy the air is on a given day. This is the metric you’ve likely seen mapped in little circles on websites like PurpleAir, turning California into a pockmarked sea of ugly purple dots as fires ramp up.

I’ve already grown all too familiar with monitoring outdoor AQIs — they determine if my son’s school is open, if I can exercise outside, and much more. But I also wanted to know what the air was like inside my house, where I spend most of my time during the day. To find out, I bought a Temtop P10 air quality monitor.

The device, which retails for $79.99 and looks like a palm-sized black rectangle with a crisp digital readout, uses a laser-based sensor to detect PM2.5 levels in the air around it. It displays the current level of PM2.5 contamination in ug/m³ and also calculates an AQI in real-time. The P10 has a six-hour battery life and charges over USB, so you can charge it up and carry it around, taking multiple readings around your house.

The Temtop P10 in my home. Images courtesy the author.

On a smoky day in early October, I charged up my P10, put it on a countertop in my home, and waited about 10 seconds for it to take a reading. The outdoors smelled like a campsite, but inside my home, the air seemed okay. I was surprised, then, to see the P10 flicker to life and show an AQI of 65. The EPA says that a 65 AQI represents “Moderate” air pollution, which puts “the elderly and children… most at risk.”

I have two kids, so learning that the inside of my home was unhealthy for them was quite a shock. To make sure the P10 was calibrated correctly, I took it out into my backyard. Within about 30 seconds, its reading had jumped to 161, an AQI consistent with the value displayed on PurpleAir.

That was good and bad — it showed the device was working properly, but also confirmed that the air inside my home was indeed unhealthy. By the evening, the air quality outside had deteriorated to an AQI around 200, and the reading in my house was approaching 90. That was uncomfortably high. I vowed to do whatever I could to bring that value down.

There are two basic ways to improve your home’s air quality when there’s smoke outside. You can keep smoke from entering in the first place, or you can filter the air to remove smoke and particulates that are already inside. To keep smoke out, the EPA says that you should keep windows and doors closed, close your HVAC system’s outside air damper, and seal leaks. My home is unusually well insulated, and I was already keeping doors and windows closed (for the most part). So I decided to turn to filters.

Smoke is harmful largely because it contains fine particulate matter.

I started by swapping out the filter on my home’s HVAC (heat and air conditioning) system. If you have central heat or air conditioning, your home or apartment likely has a filter on its main air intake, which is often referred to as a “return air duct.” Your system uses this intake to grab air from inside your home, so it can heat or cool the air. Because all the air in your home passes through the return air duct, its filter is one of your first lines of defense against indoor air pollution. Window and in-wall air conditioners have filters, too — usually integrated into the unit itself.

You should be changing your system’s filter every 90 days — or every 60 days if you have pets. If you had no idea this filter existed until you read this, drop everything and change it now. If you haven’t changed it in a few months — or ever — you might be shocked to see how dirty yours is. I hadn’t changed my filter for about five months, and it was already caked in dust when I went to swap it out.

My filter was caked in dust after five months of use.

According to Wirecutter, Home HVAC filters are rated using a scale called MERV, or Minimum Efficiency Reporting Value. MERV 1–7 filters remove big particles like pollen, household dust, and mold spores. They’re cheap and allow for good airflow, but they don’t filter particles below three microns. That means they won’t work against the fine particulates in wildfire smoke, which are 2.5 microns or smaller.

Filters in the 8 to 11 MERV range, in theory, do much better. When I first installed a new filter, I used one with an 11 MERV rating from Utilitech. I had never heard of this manufacturer, but their filters were the only ones in stock at Lowes when California’s wildfire smoke first arrived this year. Even with an 11 MERV filter installed, my air was still in the moderate range, so I decided to upgrade. To better clean the air in my home, I chose to install a Filtrete 1500 filter, which retails for around $20 (depending on the size of your system’s intake) and has a MERV rating of 12.

The Filtrete 1500 HVAC filter

I think of the Filtrete 1500 as the “2020 filter.” It’s designed to counter several of the airborne threats this bizarre year has thrown at us — wildfire smoke, but also “particles that carry viruses.” While Filtrete says that their filters “cannot reduce the risk or prevent the spread of the coronavirus,” the EPA only partially agrees, saying that “HVAC filters can help reduce airborne contaminants including viruses in a building or small space” and that “when used along with other best practices recommended by CDC and others, filtration can be part of a plan to protect people indoors.”

Personally, I’ll take whatever protection I can get, against both wildfire smoke and Covid-19. After installing the Filtrete 1500 in my home, I saw a noticeable improvement in indoor air quality. My Temtop P10 showed that the average AQI in my house went from the mid 60s before installing the filter to the low 50s after. That’s a big improvement for an investment of around $20, and less than 30 minutes of my time to install the new filter.

The air in my home was still unhealthy, though. To clean it further, I turned to another technology — High Efficiency Particulate Air (or HEPA) filters. HEPA filters have a MERV rating between 17–20. That means that they remove 99.7%+ of particles down to .3 microns — more than enough to clear harmful PM2.5 particles from the air. HEPA filters are so dense, and filter air so effectively, that you can’t just stick one into your existing HVAC system. Only specially designed systems, like those used in hospitals, can accommodate a HEPA filter at the scale of a full building.

Instead, most people who want to use HEPA filters purchase dedicated air purifiers. These standalone appliances have powerful fans, which are capable of pulling air through the dense pleats of a HEPA filter for thousands of hours on end. In choosing an air purifier for my home, I initially looked (read: drooled over) Dyson’s line of purifying fans. These are the Mercedes-Benz of purifiers, and can cost upwards of $650. I couldn’t justify spending that on an air cleaner, so instead I took a different approach; I looked at the purifiers used in medical settings.

The New York Times reports that Covid-19 has caused an epidemic of chipped teeth. I am part of that epidemic. I’ve chipped two teeth since lockdowns began, and thus have become quite familiar with my dentist, and the Covid-19 measures his practice has implemented. On one of my visits, he showed me a dentist-approved air purifier from Medify Air, and told me that he and several colleagues had placed the purifiers throughout their offices, to help remove any circulating virus particles.

Figuring that a purifier good enough to remove coronavirus in a medical setting would be plenty good enough for wildfire smoke, I looked up Medify Air’s units. I was surprised to find that they were affordable. Medify Air claims that its units use a “medical grade” or H13 HEPA filter, which the company says exceeds the standards of a normal HEPA filter, removing 99.9% of particles down to .1 microns. This likely makes it equivalent to a filter with a MERV rating around 18 — substantially more filtration than even my high-end Filtrete 1500 HVAC filter.

I bought a Medify Air MA-25 purifier for $160 on Amazon. The unit has a modern, iPod-inspired look, with sleek white sides and a glass-covered touchscreen on top. Other Medify Air devices have built-in air quality meters, but the MA-25 is more basic, with features like multiple fan speeds and an auto-off function, but little fancy tech. Below the touchscreen, two beefy H13 filters sandwich a powerful squirrel-cage fan, which pulls air through the filters and blasts it out into your room.

Medify Air MA-25

Medify Air says that the MA-25 can clean the air in a 500 square foot space every 30 minutes. I started out by placing it on the main floor of my open-concept house, a space that is about 1,000 square feet. I ran the MA-25 for about an hour, but saw little change in the AQI readings on my Temtop P10. The space was simply too big for it to purify the air effectively.

Next, I took the MA-25 into my home office, which is around 250 square feet. The smoke outside was especially bad when I ran my test, and the P10 showed an AQI of 151 at the start of my experiment. I closed the office door, ran the MA-25, and checked back in about 30 minutes. The AQI had dropped from 151 to around 20 — a reading that the EPA considers “good,” and an overall AQI reduction of 86%.

I was blown away by that result. I’ve owned air purifiers before, but I’ve never trusted that they actually did anything. Reports indicate that the purification industry is rife with false claims and exaggerated marketing. But by running the MA-25 and getting independent verification of its performance with the Temtop P10 AQI meter, I was immediately able to visualize exactly how well the unit cleaned my air. And what I found was that it had a substantial, measurable impact.

Working in my newly clean space, I felt more refreshed and productive, like an oppressive weight had been lifted — one I hadn’t even fully realized was there in the first place. This might be the placebo effect, of course. But as Reuters reports, PM2.5 air pollution has been linked to increases in the “stress hormones cortisol, cortisone, epinephrine, and norepinephrine.” In a study cited in the report, placing air purifiers in students’ dorm rooms led to meaningful reductions in the levels of these hormones, indicating that a purifier may actually decrease physical stress.

In a 2016 report, Harvard Business Review looked at the impact of air pollution on worker productivity. They found that “workers are 5%–6% more productive when air pollution levels are rated as good by the Environmental Protection Agency (AQI of 0–50) versus when they are rated as unhealthy (AQI of 150–200).” Dropping the AQI in my office from 151 to 20 may have caused a genuine increase in my productivity.

Rather than trying to purify the air in my whole home to HEPA standards, I’ve taken the EPA’s advice to create “clean rooms” — designated spaces in your home that are sealed and filtered to higher standards.”

While the report acknowledges that more research is needed, the authors speculate about why pollution reduces productivity, based on what’s already known about small particulates.

Particulate matter is small enough to be absorbed into the bloodstream, and even travels along the axons of the olfactory and trigeminal nerves into the central nervous system (CNS), where it can become embedded deep within the brain stem. This, in turn, can cause inflammation of the CNS, cortical stress, and cerebrovascular damage… If the negative impact on productivity that we found in our research are the result of diminished cognitive function, it could mean that the negative impact of pollution on productivity may be greatest in higher-skilled jobs.

That’s a terrifying thought. Wildfire smoke may not only irritate your lungs — it may actually enter your bloodstream, travel to your brain, and cause both immediate and potentially long-lasting problems. If that possibility doesn’t convince you to think seriously about improving the air quality in your home (or your company’s office, if you still have staff going there), I’m not sure what would.

Based on my research and experiments, I’m taking a multi-pronged approach to improving the air quality in all the spaces my family occupies throughout the day. I’m continuing to use the Filtrete 1500 filter in my home. I’ve also invested in two smaller Medify Air MA-14 units ($99 each), which clean a space of around 200 square feet — perfect for purifying the air in my kids’ rooms. Rather than trying to purify the air in my whole home to HEPA standards, I’ve taken the EPA’s advice to create “clean rooms” — designated spaces in your home that are sealed and filtered to higher standards, and where you deliberately spend more of your day when air conditions are bad.

I’m also looking into HEPA purifiers for my car, where I — like many Californians — spend hours each day. I try to limit outside time when the air quality is bad and wear an N95 mask (that I purchased before the pandemic) when I do need to venture out. I’m also looking into building my own air quality monitoring system using a RaspberryPI and off-the-shelf sensors, to better track air quality in my home over time and measure the impact of my HEPA filters and other filtering tech.

Even if you’re not a West Coaster — and your only exposure to wildfire smoke is through reading alarming headlines in the New York Times — you should still be aware of the air quality in your region and inside your home. The EPA says that indoor air quality can be surprisingly poor, even without wildfires. This is especially true if you smoke, burn candles, cook a lot, or live near heavy industry.

The first step toward improving your air quality is awareness — both of the potentially deadly impact of bad air, and of the current conditions around you and your family. Check sources like PurpleAir and AirNow frequently, especially during wildfire season. Consider purchasing a monitor like the Temtop P10 to spot-check conditions in your home. If your air quality is poor, look into filters or purifiers.

Wildfire smoke isn’t just annoying — it’s deadly, and can potentially cause all kinds of poorly understood cognitive and hormonal effects. Especially if you have children or elderly family members in your home, the time to improve your indoor air quality is now. A few simple gadgets — coupled with common sense routines — could increase your productivity, reduce your Covid-19 risk, improve your breathing, or even save your life.

Co-Founder & CEO of Gado Images. I write, speak and consult about tech, privacy, AI and photography. tom@gadoimages.com

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