Wildfire season is making an early arrival this year in California, with high winds and dry conditions already prompting red flag alerts and several wildland blazes in the Bay Area.
That means it’s time to prepare for the widespread smoke and bad air quality that so often accompany the worst of the season in the region — which may include looking into getting an air purifier.
Last summer and fall, the Bay Area choked under a pall of wildfire smoke for weeks. The air quality was so bad that the region set a record with more than 50 Spare the Air days for the year.
Some local hardware stores reported a spike in demand for home air purifiers during the thick of the smoke and haze last year — which coincided with the ongoing COVID-19 pandemic while many more people were working remotely.
If you’re thinking about making that investment this year, here’s what you should know about air purifiers and keeping your home smoke-free:
Why is wildfire smoke bad for me?
The short-term risks of breathing wildfire smoke include irritative symptoms such as coughing, sore throat, burning eyes, runny nose, wheezing and difficulty breathing. The effect of those symptoms on people with lung disease may be worse. Those with heart disease may have chest pain, palpitations or shortness or breath.
Do I actually need an air purifier?
On bad smoke days, it’s best to stay inside with the windows and doors closed, and keep your indoor air as clean as possible. If you have an HVAC system, experts recommend installing a high-quality air filter with a minimum efficiency reporting value (MERV) rating of 13 or higher, which filters out the particles that can get into the deep lung.
But some central air systems are not powerful enough to handle a heavy filter, said Mary Prunicki, director of Air Pollution and Health Research at Stanford’s Parker Center for Allergy and Asthma Research, so check first before installing one.
If you are in a newer home or apartment building that is tightly sealed, energy efficient and has good filtration, and you don’t have anyone in your home with preexisting lung or heart problems, or anyone who is very young or very old, then you are probably set. If not, you might want to consider investing in a HEPA filter air purifier that can help remove particulate matter from the air, including the PM2.5 fine particles from wildfire smoke.
“If you have somebody at risk of chronic respiratory or cardiac condition…or a new baby, I would opt on the side of caution in case there are fires,” Prunicki said.
And don’t wait until a big fire has already started, said John Balmes, a professor of medicine at UC San Francisco and environmental health sciences at UC Berkeley.
“If you smell smoke in your house, like last summer, then you probably have too much penetration of wildfire smoke,” said Balmes. “I recommend getting one of the devices, and I would get them now before the season because stores sell out. The time to get one is now, not when there is wildfire smoke.”
An air purifier near a patient chair at Bloom Dental Group on Friday, May 15, 2020, in San Mateo, Calif. The dental office has upgraded its safety, amid the coronavirus pandemic. It has several high-efficiency particulate air (HEPA) purifier and a device near the patient that continuously vacuums the surrounding air. The dentists have also upgraded their masks. They now wear N95 masks and face shields during procedures.
Santiago Mejia / The Chronicle
There are so many choices. Where do I start?
A good place to start is by looking at purifiers certified by the California Air Resources Board (CARB). All portable air cleaning devices sold to people or businesses in California are required to be certified by the board.
The list is separated into mechanical versions that only use physical filtration and do not generate ozone or ions, or electric ones that may be capable of producing small amounts of ozone. They usually feature ionizers that work by charging the particles in a room, and therefore may remove small particles from indoor air such as tobacco smoke.
But they do not remove gases, odors or large particles, according to the EPA, and produce ozone, which irritates the lungs. Most experts recommend purchasing a non-ozone producing purifier. The CARB-certified devices have been tested and found to only produce an ozone emission concentration less than 0.050 parts per million, and many machines with ionizers allow the user to turn the function on and off.
You can buy a very simple air purifier that just cleans the air or go for one with more bells and whistles such as fans, ones with carbon filters that help filter some odors and capture gases, and ones that have air quality monitors included.
Some versions can be pretty noisy, so keep that in mind if you are looking for something quieter.
What do they cost?
Purifiers can cost anywhere from about $100 for less expensive versions that are designed to clean very small areas, to $1,000 for high-end models that can clean much larger rooms.
One purifier is meant to clean only one room, and each model can cover only a specific square footage. This is known as the clean air delivery rate (CADR), which matches the size of the space you want to clean, so be sure to check that before buying.
You’ll also need to regularly replace the filters, which cost about $20 to $100. The pre-filter generally needs to be changed every few months and the HEPA filter is usually switched out every six months or once a year.
An air purifier which can help protect against COVID-19 sits in McCarthy’s Irish Bar in San Francisco, Calif., on Wednesday, March 17, 2021.Jungho Kim / Special to The Chronicle
Do I need a purifier in every room?
“If you have a big home it might be pretty outrageous to purchase one for every room,” Prunicki said. “Some opt to make sure one bedroom is covered…You might try to get one that has an air monitoring system with it to see the air quality with it, or buy one and move it from room to room.”
You might consider putting the air purifier in the room you spend the most time in, which for many people is their bedroom. An alternative is designating one room the “clean room,” so if there is a bad smoke day, the whole family can go into that room. If your air purifier doesn’t have an air quality monitor, you can purchase a separate device.
Air purifiers are expensive. Are there any alternatives?
Experts said people can make a DIY version with a box fan and air filter. Balmes said they “do a pretty good job” and you’ll just have to clean the filter periodically.
Can any air purifiers kill the coronavirus?
Since we’re still in the pandemic, some may find it useful to invest in a model made by Molekule or Brondell, both San Francisco-based air purifiers that are cleared by the Food and Drug Administration to kill airborne coronavirus particles through a UV-light process.
But they are pricey, ranging from $399 to $1,199, and generally more useful in hospital settings or places where coronavirus risk is higher, such as indoor dining or hotels. Prunicki said one of these devices might be useful to someone who has a lot of activity in their home with unrelated people coming indoors that would raise the risk of virus transmission.
It’s important to note that the U.S. Environmental Protection Agency says that while air cleaning and filtration can help reduce airborne contaminants like viruses, it cannot alone prevent people from contracting the coronavirus. The agency says filtration can be “part of a plan” to reduce the potential for airborne virus transmission, including social distancing and mask wearing.
Kellie Hwang is a San Francisco Chronicle staff writer. Email: [email protected] Twitter: @kelliehwang
Source: https://www.sfchronicle.com/local/article/2021-05-Air-purifiers-fire-smoke-16172112.php
