It is wise to attempt to clear out the smoke to reduce its impact on your health. However, air conditioners are not the tool to use to do this. Air conditioner filters are a very high MERV rating (which means they are poor at filtering out small particles as higher numbers are worse on the MERV scale).
The filters within most AC units can help remove some airborne particles through regular air circulation, but they fall short when it comes to effectively capturing smoke particles, which require more specialized filtration solutions.
The short answer is generally yes, it is safe to run your air conditioner during a wildfire. Even more so, your AC unit may help filter wildfire smoke out of your home.
Close Windows and Doors
If possible, use weather stripping or towels to block gaps under doors and windows. Remember to avoid using whole-house fans or window air conditioners unless they have a HEPA filter, as these can bring smoky air indoors.
Use Your Air Conditioner
In reality, your AC system helps to clean the air inside your home. By circulating air throughout the day, your AC system filters out any smoke particles as well as other types of airborne pollutants such as dust, pollen, bacteria and viruses.
The air conditioner's cooling cycle includes pulling in warm air that is then cooled. As a result of this process, condensation is produced. When moisture builds up in the heater box, it may eventually turn into vapor and get released with the cooled air, so you see white smoke coming from the air conditioner vents.
To fix this, we need better filters for air conditioners. One solution is called HEPA filters. These filters are super good at catching tiny particles, even ones as small as smoke. When we use air conditioners with HEPA filters, they can trap the smoke particles, keeping them out of the air we breathe inside.
While aircon's are not designed to filter smoke particles they can be used to an extent to lower the level of smoke inside. Some air conditioners can be set to draw fresh air from outside. If your aircon does this it's essential to turn it off the 'Fresh Air' setting to ensure it's not continually drawing smoky air in.
Filters and Air Cleaners: If you have an air conditioning system, change your filter regularly, and keep a high-efficiency filter on hand. Filters labeled “MERV13” or higher are most effective for removing smoke particles. Having a portable HEPA air cleaner available will also help to create a room with filtered air.
Even if the weather is mild, all of that smoke will enter the house through your open windows and doors and reduce your indoor air quality. This is why you should always keep your AC running and your home sealed tight whenever there is smoke in the air.
Do air purifiers really remove smoke? Yes, "Air purifiers remove smoke by using a combination of filters, primarily HEPA filters (which capture the fine particulate matter present in smoke) and activated carbon filters (which filters adsorb volatile organic compounds, or VOCs, and odors)," explains Podjasek.
Air conditioners purify air or air conditioners filter pollution. False. Air conditioners cannot and do not purify air. The air filter located near the return air duct or air handler does filter dust, pollen and other allergens.
Air cleaners with HEPA (High-Efficiency Particulate Air) filters remove airborne particles (fire smoke, other pollutants, cigarette smoke, coronaviruses, pollen, pet dander, etc.), and models with activated carbon filters will also remove VOCs and most odors.
Using the car's air conditioning system alone may not effectively reduce pollution from wildfire smoke inside the vehicle. This is because smoke particles are very small and can easily enter the car through ventilation systems.
Smoke particles, especially from wildfires and tobacco, are extremely small (0.1 to 1 micron). Standard residential HVAC filters (typically MERV 1-8) are designed to capture particles 3 microns and larger, allowing many smoke particles to pass through.
The simplest thing you can do to purify air from smoke in your home is just opening windows. Letting in a cool breeze will help whisk away some of the smell and bring badly needed fresh air into the home. This can provide some immediate relief for rooms with a stronger presence of smoke in the air.
“Activated charcoal also is an option to help absorb odors. Use it like you would baking soda and place it in bowls around the house for several days. Keep closet doors open, as well as other doors you may typically keep closed. Include kitchen and bathroom cabinets, too,” she said.
The EPA recommends filters with a rating of at least MERV 13, or, “as high a rating as your system fan and filter slot can accommodate.” MERV stands for “minimum efficiency reporting value,” and it is a measure of how well a central-air filter removes particulates from the air.
The time it takes to clean a house from smoke damage varies a lot. It depends on how bad the damage is. For minor smoke damage, like surface stains and smells, it might take a few days to a week. But, if the fire was really bad, it could take weeks or even months to fix everything.
After the Fire
It is wise to attempt to clear out the smoke to reduce its impact on your health. However, air conditioners are not the tool to use to do this. Air conditioner filters are a very high MERV rating (which means they are poor at filtering out small particles as higher numbers are worse on the MERV scale).
So can an AC remove the smell of smoke? While it is not recommended to smoke near your AC, you can remove the smoke smell from your home by opening the windows a little more than usual and starting the air conditioner in “ventilation” mode on one of the higher fan speeds.
Running your system on constant fan will run air through your filter more often, reducing the amount of dust your family breathes in your home.
Does AC purify smoke? Air conditioners may filter out some components of smoke, such as larger particles and visible particulate matter. However, they are not designed to completely purify smoke or remove all harmful substances present in it.
An HVAC air filter will catch much of the smoke in your home—assuming it's a good one. “You want a filter with a high MERV rating,” says Dave Trezza, an engineer who has tested air filters at Consumer Reports.
If you use portable air conditioners, the number of hoses will dictate whether they're safe to use in smoky conditions. Models with a single hose can pull smoke inside, meaning you should avoid operating them in these environments. If yours is a two-hosed model, check for a secure seal between the window and vent kit.