What filter should I get? MERV ratings explained.
If you’ve ever gone to buy a new air filter, seen the term “MERV rating” and wondered what on earth it means, then don’t panic, you’re not alone.
And although a MERV rating (which stands for Minimum Efficiency Reporting Value) sounds complicated, in reality, it’s quite straightforward; it’s a rating that tells you how effective your air filter is in comparison to other air filters on the market.
In other words, the higher the MERV, the more effective the filter is at capturing small particles.
For residential settings, like your home or office, MERV ratings go from 1 to 13.
(MERV ratings actually go up to MERV 16, but 13-16 are usually for factories and medical environments.)
But we know that all those letters and numbers can get a little confusing, so we thought we’d break down a few of the most commonly asked MERV questions…
“What difference does a MERV rating make to my air quality?”
The MERV rating indicates how effective the filters are at removing different size particles from the air you breathe.
At the top end of the residential scale, a MERV 11 to 13 filter will remove the most particles and contaminants — from the visible ones like smoke and dust to pollen and other microscopic allergens — from the air you breathe, while MERV 1 filters are great for airflow but are designed to remove the larger particles like dust and pollen.
On a more scientific level, MERV 11 to 13 filters can remove particles from 10 microns to as small as .3 microns from the air, while MERV 1 removes the particles that closer to 10 microns in size.
For scale, 100 microns is about the thickness of a human hair, so even MERV 1 filters remove particles that are still very small.
Is a higher MERV rating always better?
It’s a common misconception that you should always choose the filter with the highest MERV rating.
And, on the surface, it makes sense: a higher MERV rating means fewer particles and contaminants in the air, which equals better air quality.
However, as you increase the MERV rating, you decrease the size of the holes that allow air to flow through your HVAC filter.
If your system wasn’t designed to handle a filter with a high MERV rating, this can reduce the airflow into your home, worsening the air quality and — in some cases — causing damage to your furnace.
Which filter is right for you?
If You notice cold spots in your house or have issues with airflow: FIBERGLASS
A fiberglass filter will allow your system to operate as efficiently as possible.
If you don’t have allergies a requirement for small particle capture: MERV 8
A MERV 8 filter will significantly reduce the amount of pollen and dust from the air in your home. For the average household the MERV 8 will be the perfect filter.
If you have have allergies or would like a higher level of filtration: MERV 11
A MERV 11 filter will — just like a MERV 8 filter — significantly reduce the amount of pollen, dust, dust mites, mold, and bacteria in your home’s air, while also removing a higher percentage of the smaller particles floating around and causing allergy flare-ups.
So, there you have it, a few common MERV FAQs answered. Is there something else you’d like to know? Let us know!