If you live near wildfire smoke, you probably need a new HVAC filter — how to know if you need to change your home's air filter

Yahoo

15-07-2025

As wildfires continue to burn across Canada, air quality warnings have been issued throughout the country. During times of poor air quality, experts advise staying indoors in a cool, air-conditioned environment.
Beyond shutting your doors and windows to wildfire smoke, the right HVAC filter can serve as a critical first line of defence against smoky air and other airborne pollutants. If you're interested in learning more about HVAC filters and how to improve the air quality of your home, scroll below to discover why MERV ratings matter and to shop top-rated air filters for your home.
If you're like most consumers, it may come as a bit of a surprise that not all HVAC filters are created equal. When it comes to filtering out those nasty particles floating about, the top of mind spec to keep in mind is the MERV rating — a nerdy acronym that stands for Minimum Efficiency Reporting Value.
On a ratings scale of one to 16, look for MERV 12, 13 or 14 filters, which are capable of removing microscopic particles, including fine particulate matter (PM 2.5) from smoke, aerosols, mould, bacteria and pollen. Which, left unchecked, can lead to a host of respiratory problems, especially for the more vulnerable members of society.
Here's a rundown of some of the top-selling filters to consider.
Meets MERV 13 rating with a mid-range price tag. One of the product's strengths is enhanced air flow to ensure less strain on your HVAC motor.
Meets MERV 13 rating with a mid-range price tag. One of the product's strengths is enhanced air flow to ensure less strain on your HVAC motor.
While these 3M MERV 13 filters don't have the same Bluetooth connectivity as the company's MERV 12 sister product, they're more efficient when it comes to capturing airborne pollutants.
Protect your home for years to come when you bulk buy these Canadian-made MERV 13 filters.
If you want to up the IQ of your smart home, 3M's Filtrete Smart Air Filter could be your product of choice. This MERV12 filter comes with built-in Bluetooth sensors you can pair with the company's proprietary app for both iOS and Android devices.
Based on air flow, usage and time, the app sends notifications to your phone when it's time to change the filter. A bonus feature is that the app gives you tips on how to improve air quality in your home.
These filters also have a high Microparticle Performance Rating (MPR) for capturing particles not visible to the naked eye.
Two key considerations before you buy:
Check the size of your existing HVAC filter to ensure the filter you're ordering is the right fit for your furnace.
Check the HP/Horsepower rating of the motor on your furnace.
For the latter, most furnaces with 1/3 to 1/2 HP motors can handle MERV 13 filters, whereas your furnace motor should be 1/2 to 3/4 HP for MERV 14 due to the tighter weave. If you have an older HVAC system with a lower HP motor, it could reduce airflow and cause a strain on the system.
A safe rule of thumb is to have your HVAC system checked at least once a year, at which time you can also confer with your service technician to ensure your system can handle MERV 13 or even 14 filters. Or just go have a look yourself: the HP rating is usually plain to see on the furnace motor.
Also, make a point of checking the condition of your filter on a monthly basis. Most are rated to last three months, but that could be significantly shortened if your area experiences a spike in poor air conditions.
A final consideration is that MERV 13 is the proverbial "sweet spot" of air filters in that they remove more pollutants from the air than MERV 12 but provide better air flow, meaning less strain on your HVAC motor than MERV 14.
Taking the time to learn more and making a relatively modest investment in these higher-priced but also more efficient filters can serve as a critical first line of defence for your home against airborne pollutants, so you can breathe a little bit easier the next time you're faced with a drop in outdoor air quality.
Lastly, if you don't have a forced air furnace system (i.e. you have radiant heat), you can still fight poor quality air with room air filters. Apart from helping to clean air coming in from outside, these filters provide a critical "second line of defence", especially against harmful pollution caused by natural gas stoves, if you have one.