Wildfire Smoke in the Pacific Northwest: Is the Air Inside Your Home Really Clean?
When wildfire smoke settles into Northwest Washington, we can usually see it outside. The mountains disappear behind a layer of haze, the sky takes on an unusual color, and sometimes you can even smell smoke the moment you step outdoors.
But what about the air inside your home?
After a stretch of smoky summer weather, many homeowners assume that closing the windows and doors is enough to keep the smoke outside. Unfortunately, wildfire smoke can still make its way indoors, and some of the smallest particles can remain suspended in the air long after outdoor conditions begin to improve.
For homeowners throughout Lynden, Bellingham, Ferndale and Whatcom County, August is a great time to think about more than keeping your home cool. It’s also a good time to think about the air your family is breathing.
Wildfire Smoke Doesn’t Always Stay Outside
Wildfire smoke contains extremely small airborne particles. Even with your windows and doors closed, some outdoor air can enter your home through small gaps, ventilation systems and normal air exchange.
Once those particles are indoors, your HVAC system can either become an important part of improving your home’s indoor air quality or, if the system isn’t properly set up and maintained, it may not provide the level of filtration you expect.
That’s why your air filter deserves some extra attention during wildfire season.
Check Your HVAC Filter After a Smoke Event
When was the last time you looked at your furnace or HVAC filter?
If you can’t remember, now is a good time.
During periods of wildfire smoke, filters may collect particles more quickly than they normally would. A filter that typically lasts several months may need attention sooner depending on the amount of smoke, how frequently your HVAC system operates, the type of filter you’re using and conditions inside your home.
A dirty or overloaded filter can also restrict airflow and make your heating and cooling system work harder.
After a significant smoke event, check your filter rather than simply relying on your normal replacement schedule.
Would a Higher-Efficiency Filter Help?
Not all HVAC filters provide the same level of filtration.
One measurement you’ll often see on filters is the MERV rating, which stands for Minimum Efficiency Reporting Value. Generally, a higher MERV rating means the filter is capable of capturing smaller airborne particles.
The U.S. Environmental Protection Agency recommends considering a MERV 13 filter, or the highest-efficiency filter your HVAC system can accommodate, to help reduce fine particles associated with wildfire smoke.
But there is an important catch:
Don’t simply install the highest-rated filter you can find.
Your HVAC system needs to be capable of moving air effectively through that filter. Installing a filter that creates too much resistance can reduce airflow and potentially affect system performance.
If you’re unsure which filter is appropriate for your equipment, an HVAC professional can help determine the right balance between filtration and proper airflow.
Your HVAC Settings Matter, Too
During periods of poor outdoor air quality, how you operate your HVAC system can make a difference.
If your system brings in outdoor air, it may have a fresh-air intake or ventilation setting that can be adjusted during smoky conditions. Depending on the equipment installed in your home, using a recirculation setting may help reduce the amount of smoky outdoor air being introduced.
Running air through an appropriate high-efficiency filter more frequently can also help capture particles already inside the home.
Every HVAC system is different, however, so it’s important to understand how your particular system is designed before changing settings.
What About Portable Air Purifiers?
Portable air cleaners can provide another layer of filtration, particularly in bedrooms, living areas or other rooms where your family spends a significant amount of time.
When selecting one, look for a unit appropriately sized for the room. The Clean Air Delivery Rate, commonly called CADR, can help you compare how effectively different units filter airborne particles.
It’s also important to choose an air cleaner that does not intentionally produce ozone.
For some homes, a combination of good central HVAC filtration and properly sized portable air cleaners can provide additional protection during periods of heavy wildfire smoke.
Don’t Forget About Indoor Sources of Air Pollution
When outdoor air quality is poor and the house is closed up, it also helps to reduce the particles you’re creating inside.
Activities such as burning candles, using a wood-burning fireplace and certain types of high-temperature cooking can add particles to your indoor air.
During a smoke event, reducing these activities can help your filtration system focus on removing the particles already present.
When the Smoke Clears, Your HVAC System May Need Some Attention
Blue skies returning doesn’t necessarily mean everything immediately goes back to normal inside your home.
After several smoky days, consider giving your home’s HVAC system a quick post-smoke check:
- Inspect your HVAC filter and replace it if it is dirty.
- Make sure supply and return vents aren’t blocked.
- Pay attention to unusual airflow or changes in system performance.
- Consider whether your current filtration is appropriate for future wildfire events.
- Once outdoor air quality improves, safely ventilate your home to introduce cleaner outdoor air.
Wildfire smoke has unfortunately become something Pacific Northwest homeowners increasingly need to be prepared for. A little preparation before the next smoky stretch can make it much easier to protect the comfort and indoor air quality of your home.
Cleaner Indoor Air Starts With the Right HVAC System Setup
At Reliance IAQ, indoor air quality isn’t an afterthought. It’s right in our name.
We help homeowners throughout Lynden and the surrounding Whatcom County area understand how their heating, cooling, ventilation and filtration systems work together to create a healthier, more comfortable indoor environment.
If this summer’s wildfire smoke has you wondering whether your HVAC system is doing enough to filter the air inside your home, we’re happy to help.
From checking your system and recommending the appropriate filtration to discussing indoor air quality solutions for your home, the Reliance IAQ team can help you prepare for the next smoky day before it arrives.
Because when the air outside isn’t at its best, your home should still be a place where you can breathe a little easier.