How to Select the Right MERV Rating for Your Furnace Filter

Determining the right MERV rating for your furnace filter can be difficult. There are various types of filters to use, and it might be hard to select a filter that best suits your needs. We’re here to help. Knochelmann Service Experts is your local HVAC Expert in Sharonville, helping you make informed decisions for your home.

Choosing the right furnace filter is all about balancing indoor air quality with your HVAC system’s capabilities. Finding filters with the right MERV ratings is critical to ensuring your air is well-filtered without overworking your HVAC system.

What Does MERV Mean?

A minimum efficiency reporting value, or MERV is a rating system created by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). MERV ratings denote an air filter’s effectiveness at decreasing airborne particles and contaminants. A filter’s rating is determined by the minimum size particle it’s capable of capturing (measured in microns). As filters become more effective at improving indoor air quality, their MERV rating increases, ranging from 1 to 20.

Below, you will find a chart that can help you determine the recommended MERV rating for a variety of settings.

MERV Range Controlled Contaminants Typical Application Air Filter Types
1-4 Pollen, Dust, Spray Paint, Dust Mites, Sanding Dust, Textile & Carpet Fibers Residential, Window AC Units Disposable Electrostatic
5-8 Mold Spores, Pet Dander, Hair Spray, Dusting Aids, Fabric Protector, Cement Dust, Pudding Mix Better Residential, Commercial, Industrial Workplaces Pleated Filters Cartridge Filters Electrostatic
9-12 Legionella, Auto Emissions, Lead Dust, Humidifier Dust, Welding Fumes Superior Residential, Better Commercial, Hospital Labs Pleated Filters Cartridge Filters
13-16 Bacteria, Droplet Nuclei (Sneeze), Tobacco Smoke, Insecticide Dust General Surgery, Hospital Inpatient Care Bag Filters Box Filters
17-20 Viruses, All Combustion Smoke, Carbon Dust Cleanrooms, Radioactive & Carcinogenic Materials, Pharmaceutical Manufacturing HEPA Filters Specialized Filters

Other Measurement Systems

Knowing about MERV ratings might not be enough when the time comes to purchase your furnace filter. For example, some major retailers use the filter performance rating (FPR), which ranges from 1-10 and measures a filter’s ability to trap large and small particles. You might also see the microparticle performance rating (MPR) system, which ranges from 300 to 2200 and measures a filter’s effectiveness at capturing only the smallest particles on the MERV scale (0.3-1 microns in size).

You can use the chart below to better understand how filters ranked with FPR and MPR stack up to the more standard MERV rating system.

MERV Rating FPR MPR
MERV 1-5 Below Minimum FPR Below Minimum MPR
MERV 6 Below Minimum FPR MPR 300
MERV 8 FPR 5 MPR 600
MERV 11 FPR 7 MPR 1000-1200
MERV 13 FPR 10 MPR 1500-1900
MERV 14-20 Above Maximum FPR MPR 1900+

What Should My Furnace Filter’s MERV Rating Be?

Choosing the right MERV rating for your air filter is a delicate balance between your HVAC system’s capabilities and the indoor air quality you want to have.

For example, a higher MERV rating doesn’t always mean that a filter is the best option for your furnace. In fact, as MERV rating increases, air flow decreases—forcing your HVAC system to work harder to push air through your furnace, increasing the possibility of a potential breakdown. Before buying a new furnace filter, be sure to check if your HVAC system has a maximum MERV rating. If it has one, be sure to get a furnace filter with a MERV rating below your system’s maximum.

If your family has allergies or serious respiratory issues like asthma, you may want to invest in filters with higher MERV ratings. Remember, there are always other solutions out there to improve your indoor air quality if your system is unable to handle the MERV ratings you require.

Generally speaking, our recommended MERV rating for furnace filters ranges from 6 to 8 for a great balance between maximum furnace efficiency and home comfort.

Choosingthe right MERV rating for your furnace filter has a huge impact on your indoor air quality, your HVAC system and, most important, your family’s well-being. Let Knochelmann Service Experts help you make a smart decision. We carry a full line of air filtration solutions plus our Expert knowledge and service—and we’re available 24/7 for emergencies. Contact us at 866-397-3787 to schedule your indoor air quality consultation in Sharonville today!