Reduce wildfire smoke with your HVAC system
Author: Bill Hoelzer / Updated: May 2021 / Read Time: Six and a Half Minutes
Wildfire smoke is nasty. We're talking about thousands of individual compounds, many of them toxic and small enough to enter your bloodstream.
We’ll walk through the best ways to protect your home from wildfire smoke with heating, ventilation, and air conditioning (HVAC). You’ll find tips and tricks to get cleaner air from your central air conditioner, heat pump, or gas furnace.
If you want to take things to the next level, you can protect your family with hospitable grade air filtration. We’ll introduce advanced ventilation systems, like an electrostatic air filters.
The bottom line - You have a lot of options to breathe easier during wildfire season.
Time to upgrade your HVAC system?
If you’d like an appointment for heating, ventilation, or air conditioning for your home in Bend or Portland, please give us a call at 541.330.876. You’re also welcome to self-schedule online. Every client gets a satisfaction guarantee.
Article Highlights
Cheat sheet to reduce wildfire smoke with HVAC
Order an extra air filter for wildfire season: Don’t wait until the smoke starts! A few tips: Make sure you get the right size air filter. During wildfire season, go with MERV 13 or higher, and look for a filter with activated carbon (also called activated charcoal).
Get an air purifier: Here’s another thing to order BEFORE wildfire season - an air purifier like the Coway AP-1512HH Mighty. For less than $200, you’ll get an extra layer HEPA filtration in a room.
Know your exposure: When the air seems smokey, check AirNow.gov for real time air quality updates.
Don’t make your indoor air worse: If you’re advised to stay indoors, avoid making your indoor air worse by smoking, burning candles, running a gas stove, etc. You’ll also want to limit your vacuum usage.
Circulate and filter air through your HVAC system: Replace your air filter, then use your central air conditioner or heat pump as you normally would. If you don’t have central cooling, turn on the fan at your thermostat to circulate air through your filter.
Plug up big air gaps and holes: If you use window air conditioners, replace the plastic side panels with pieces of rigid foam board secured with easily workable rope caulk. You’ll want to cover up any duct connections to the outdoors (not the combustion air intake for your furnace).
Consider an advanced ventilation system: We recommend the Aprilaire 5000, which removes ultra-fine particles as small as 0.3 microns from your indoor air.
What's in wildfire smoke?
Wildfire smoke is a shifting blend of gases and particles, including carbon dioxide, water vapor, carbon monoxide, hydrocarbons and other organic chemicals, nitrogen oxides and trace minerals.
Tiny, tiny particles: What worries doctors most is the particulate matter in smoke - the tiny bits of feathery ash and dustlike soot, much of it invisible to the eye. They're especially worried about particulate matter less than 10 microns wide, known as PM 10. (By comparison, a human hair is about 60 microns wide).
Doctors also dread the subset known as PM 2.5, for particulate matter less than 2.5 microns wide. These tiny particles travel deep into the lungs and the smallest ones can even enter the bloodstream. The smallest particles are also the lightest, and can travel vast distances on the wind.
The particles first damage the body simply by getting inside of it – triggering inflammatory reactions that themselves can trigger breathing difficulties, heart attacks and even strokes.
Within a few days of smoke exposure, damaged lungs can succumb to bronchitis or pneumonia. In pregnant women, exposure to particulates has been associated with premature birth and low birth weight in infants.
WHAT ABOUT CANCER OR CHRONIC CONDITIONS?
Do you run a higher risk of cancer or other chronic health conditions (e.g. heart disease) from short-term exposure to wildfire smoke? In general, the long-term risks from short-term smoke exposures are low.
Short-term elevated exposures (i.e. over days to weeks) to carcinogens found in wildfire smoke are also small relative to total lifetime exposures to carcinogens in other, more common combustion sources.
Who's at the greatest risk?
Heart + Lung Conditions: People who have heart or lung diseases, like heart disease, chest pain, lung disease, or asthma, are at higher risk from wildfire smoke.
Older Adults: Older adults are more likely to be affected by smoke. This may be due to their increased risk of heart and lung diseases.
Children: Children are more likely to be affected by health threats from smoke. Children’s airways are still developing and they breathe more air per pound of body weight than adults. Also, children often spend more time outdoors engaged in activity and play.
understand the air quality around and in your home
Check out AirNow.gov, a stellar resource from the U.S. EPA. When you enter your zip code, you'll see how clean or polluted your outdoor air is, along with associated health effects that may be of concern.
Google (as usual) provides a shortcut - When you search for "air quality portland" or "air quality bend", Google pulls data from AirNow.gov and presents it at the top of your browser.
If you want diagnostics on your home in particular, we offer AirAdvice testing to measure 6 common indoor air quality concerns: (1) particulate matter, (2) chemical off-gassing, (3) carbon dioxide, (4) carbon monoxide, (5) temperature, and (6) humidity.
Click here to see a sample Air Advice report from GreenSavers. We offer two different indoor air quality tests: one shorter and one longer. The shorter tests takes about 30 minutes and costs $95. The longer test lasts for up to 48 hours and yields much more accurate results. It comes with a price tag of $200.
To schedule an indoor air quality test for your home, please give us a call at 541.330.8767.
Avoid making your indoor air worse
Shut it: Start by shutting your windows and doors if you're advised to stay inside.
Do you smoke? Get some Nicorette: Avoid activities that increase indoor pollution, like smoking, burning candles, and using a gas stove.
Limit the vacuum: You'll also want to limit your vacuum use (unless you have a vacuum with a HEPA filter) to avoid stirring up particles that are already inside your home.
What if you don’t have air conditioning?
If you don’t have AC and depend on open windows and doors for ventilation, it can be dangerous to shut yourself inside. There's an increased risk of heat stress. Older people and others in frail health are more likely to experience heat exhaustion or heat stroke, both of which can have serious consequences.
We strongly recommend air conditioning for hot days when you're advised to stay inside. If air conditioning isn't feasible for you at this time, it's best to stay with friends, family or neighbors who have an AC system.
What about window air conditioners? The main issue with using a window air conditioner during wildfire season is that the plastic side panels typically let in lots of outdoor air. We recommend replacing the side panels with rigid foam board secured with easily workable rope caulk.
Furnace filter for wildfire smoke
Order an extra air filter in advance
If you wait until wildfire season, you could end up waiting weeks to get your new air filter. Take a few minutes now to order an extra filter. You’ll thank yourself when the smoke starts.
Get the right size air filter
Most high efficiency furnace filters come in the following sizes: 16″ x 20″ x 4”, 20″ x 25″ x 4”, and 16″ x 25″ x 4”. Start by turning off your HVAC system, then opening up your filter cabinet. Do you see three numbers on the side of your furnace filter? Does the filter fit snuggly in its cabinet? If so, then you’re good to go. Use the three numbers on the side of your air filter to order another of the same size.
Go for a high “MERV” rating
The Minimum Efficiency Reporting Value (MERV) rating measures how effectively a filter does its job. MERV ratings run from 1 (the least filtration) to 20 (the most filtration).
For an everyday furnace filter, we typically recommend a MERV 11 for our clients. A MERV 11 filter strikes the right balance between cost and performance.
But for wildfire season, you should order a furnace filter with more filtration. MERV 13 to 16 filters will reduce reduce indoor particulates as much as 95%.
Prioritize activated carbon filters
Filters with activated carbon (also called activated charcoal) do a better job of removing volatile organic compounds (VOCs), odors, and gaseous pollutants like wildfire smoke. Carbon air filters trap gaseous molecules on a bed of charcoal, rather than letting them enter your home.
The best HVAC filter for wildfire smoke
Here’s an example of a MERV 13 activated carbon HVAC filter for wildfire smoke. Please note that this particular filter is 20″ x 25″ x 4.” Whichever filter you choose, be sure to order the right size.
Circulate and filter air through your HVAC system
If you have a cooling system, like central air conditioning, a heat pump, or a ductless heat pump, simply use your system as you normally would. By default, these systems re-circulate air in the home, so they filter air without pulling in additional particulates from outdoors. I
f you have a heating system, like a gas furnace, or a cooling system that you're not currently using, we recommend turning the fan on at your thermostat. This will re-circulate air and help to filter out particulates.
Consider an advanced home ventilation system
Aprilaire Electronic Air Purifier Model 5000
When you install an air purifier, the air in your duct system runs through electrostatic HEPA filter. This hospital grade filter eliminates viruses and ultra-fine particles as small as 0.3 microns from the air in your home. We recommend the Aprilaire Electronic Air Purifier Model 5000, which has an estimated price of $1K to $1.5K.
If you’d like an appointment for an advanced ventilation system, please give us a call at 541.330.8767, or self-schedule online.
Bringing it all together
Wildfire smoke should be taken seriously, especially for sensitive populations (e.g. children and people with asthma). It's important to pay attention to the quality of the air near your home.
Check out AirNow.gov. When you're advised to stay indoors, keep the windows and doors shut and avoid doing things that make air quality worse, like smoking or burning candles.
If you have a central air system, make sure you have a fresh air filter with a high MERV rating as well as activated carbon. You can filter air in your home by running your cooling system (AC, heat pump, or ductless heat pump). If you have a heating system (gas furnace) or a cooling system you're not currently using, turn the fan on at your thermostat.
For the best possible air quality in your home, consider installing an electrostatic whole home air filter. Please don’t hesitate to call with questions: 541.330.8767.