What MERV Rating Do I Need?

When it comes to choosing air filters for your home HVAC unit, two things are critical: picking the right filter and maintaining a regular filter replacement schedule. To the first point, many people ask, “what MERV rating do I need for my home’s next air filter?” There is a lot to know about MERV air filters, but to put it succinctly, many homes would benefit from a MERV 8 filter or higher, depending on several factors which we’ll discuss below.

For now, understand that higher MERV ratings are correlated with higher efficiency at trapping impurities in the air, but there is a balancing act homeowners need to perform when choosing a filter that is highly effective but that doesn’t overly tax their HVAC system in the process.

What Is a MERV Rating?

First, let’s define MERV. MERV air filter ratings, which are measured on a scale of 1-16, are short for Minimum Efficiency Reporting Values. Generally, higher MERV ratings will trap smaller particles, but as you’ll see, it’s not quite as simple as that. Higher MERV ratings do, in fact, indicate higher ability to trap pollutants and particles. However, it is important to check with your HVAC dealer to make sure that your system can accommodate a higher MERV rated filter. If you use a filter rated for a larger unit, it could lead to restricted airflow.

The MERV rating system was developed in late 1987 by the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) in an effort to develop industry standards for air filters.

In general, a filter’s MERV rating correlates with the size of particle it can efficiently remove. Some MERV filters are better at trapping particles in the size range of pet dander and dust mites, while others are particularly effective at filtering airborne particles in the size range found in tobacco smoke.

This rating system is a useful tool when it comes to comparing the efficiency of air filters for your home. Would it surprise you to hear that the air quality in your home can be two to five times more polluted than the outside air?¹ The Environmental Protection Agency (EPA) states that fine inhalable particles pose the greatest risk to health and are generally 2.5 microns (PM 2.5).²

Many allergy and asthma sufferers have come to rely upon the MERV rating system to weed out ineffective, low quality air filters from those that actually filter more impurities. By assigning lower numerical values to help identify the efficiency of air filters, consumers can make an informed decision regarding what type of home air filter they use.

MERV Filter Ratings Chart

In this MERV rating chart found below, we’ll explore how various MERV furnace filters and air filters work to trap certain sized particles and how these capabilities correlate with filter efficiency. Keep in mind, a higher MERV rating is not appropriate for all HVAC system types.

How MERV Filter Ratings Affect Air Quality

As we’ve mentioned, the MERV rating system’s numbers are relative to how efficient the filter is at trapping particles in your home’s air and choosing the right filter rating can be very important if you’re looking to trap small particles and allergens or impurities circulated in the air in your home.

If your system is not capable of handling filters with higher MERV ratings, you might want to speak to your HVAC dealer about selecting filter with a MERV rating that is more in the middle range, between 8 and 10. Which one of these you choose comes down to how much you’re willing to invest in a quality air filter combined with any considerations about your HVAC unit’s capabilities. A filter with a rating of MERV 16, for instance, is designed to be used in more of a commercial setting. As you can imagine, a higher rated filter requires a very powerful HVAC unit to effectively push air through it while trapping impurities in the air. MERV air filters with a very high rating could overwork the average home HVAC system — even to its breaking point — while driving heating & cooling utility bills through the roof. That’s why choosing an appropriate filter that do not unreasonably restrict airflow is crucial.

On the other hand, a filter with a low MERV rating may not do much for the indoor air quality of your home. A MERV rating of 1 may be effective in filtering out larger fibers particles and may be minimally effective for other smaller particles, but this level of air filtration is not generally recommended in residential or business settings.

With this information in hand and knowledge of which filters trap certain particle sizes, you can begin to get an idea of which MERV filter rating will work best in your home.

What Level MERV Rating Do I Need?

The ideal MERV rating depends on your specific air quality needs and HVAC system capabilities. Generally, for residential use, a MERV rating of 13 or higher is recommended to effectively capture common indoor particulates*. However, it's crucial to consult a local HVAC professional to determine the most suitable MERV rating for your circumstances. 

MERV Rating FAQs

Is the higher the MERV rating the better?

In short, yes. The higher the MERV rating, the better the HVAC system using that MERV filter will be at filtering pollutants in your home's air. However not every system can handle every MERV rating. As mentioned in this article, choosing a MERV filter higher than your HVAC system can handle can accelerate wear and tear of your HVAC components, increase utility bills, and restrict air flow. Make sure to contact your local Carrier dealer for any questions on this subject. 

If you have any questions, you can always contact your local Carrier HVAC dealer with questions.

Some of our most popular MERV filters include MERV 8, MERV 10 and MERV 13 filters. Shop Carrier 1” air filters.

1. https://www.epa.gov/report-environment/indoor-air-quality

2. https://www.epa.gov/pm-pollution/particulate-matter-pm-basics