Most Popular Filter Sizes
MERV 11 vs. MERV 12
We’ve been talking a lot lately about MERV ratings, what they are and their importance in choosing the best filter for your residential system. To review, MERV stands for Minimum Efficiency Reporting Value. This is a system designed to minimize confusion on air filters and their capabilities, showing consumers which environmental pollutants MERV-rated filters can trap. Overall, the system ranges from 1 to 16, with the higher end trapping the most particles and lower end catching the least.
If you’re a regular Joe Schmoe with a regular furnace/AC system, you only need to be concerned with ratings somewhere between 7 and 12. Any higher and you’re spending more money for no good reason – those high ratings (13, 14, 15, 16) are reserved for clean rooms, labs and hospitals. For your purposes, you should be concerned with a filter that filters most household irritants, such as:
- Humidifier dust
- Lead dust
- Auto emissions
- Milled flour
- Pet dander
- Mold spores
- Dust mites
- Plant spores
Luckily, MERV 11-rated filters handle those particles -- such as pet hair and dust mites -- with ease. Likewise, MERV 12 filters catch about the same types of particles. The difference between 11 and 12, therefore, is quite negligible. We do not carry MERV 12; MERV 11 does just as good a job.
But to get more into detail over the two, consider that MERV 11 filters trap 65 to 79 percent of average particles of 1.0 to 3.0 microns in size, with an average particle size efficiency of 85 percent or better. MERV 12 filters trap 80 to 89 percent of average particles of 1.0 to 3.0 microns, with an average particle size efficiency of 90 percent or better. As you can see, they’re pretty close. That’s why you’re just as good going with a MERV 11 as with a MERV 12. You will get decent results from either.
If you think the higher the rating, the better the filter, remember: Filters with higher MERV ratings have smaller pores through which air can flow, leading to more resistance and stress on your furnace system. What you get is an inefficient filter over time. Why even have one in the first place if you’re going to render it inefficient? And you certainly don’t want to decrease the quality of air in your home, put your family’s health at risk and stress your HVAC system due to reduced air flow.
The most important thing – even more important than the individual rating number – is to change your filter regularly. Check the box: what does the manufacturer recommend? Go by that date, put in your smart phone, add it to your calendar, whatever you have to do to remember it. If you let it go too long, well, you’ll see just how much dirt has accumulated due to this neglect when you finally do change it. You will wonder what good it did anyway! An affordable lower MERV filter that’s changed as recommended is far better than an expensive higher MERV filter that hardly ever gets changed.
Filtration Montreal has all the MERV 11 filters you need all in one convenient place. Order in bulk and you’ll never be without a new filter at changing time.