Have you ever taken a close look at your HVAC filters when replacing them? If so, you may have noticed that each filter has a MERV rating – and this number has important implications.

TL;DR – What to Know About Air Filter MERV Rating

  • MERV (Minimum Efficiency Reporting Value) measures how well HVAC filters remove particles from the air.
  • Higher MERV ratings mean better filtration but require stronger HVAC systems to handle denser filters.
  • Using a filter with too high a MERV rating can strain your system, reduce efficiency, and lead to costly repairs.
  • Check your HVAC system's documentation for the recommended MERV range to avoid issues.

What Does MERV Stand For?

MERV stands for “minimum efficiency reporting value” and the MERV rating is a measure of how effectively a filter removes particles from the air that passes through it. The higher the MERV rating, the more particles the filter will catch.

There’s a flipside to this, though. Filters with higher MERV ratings generally feature denser filtration material, which means more force is required to push air through the filter. It takes exceptionally powerful HVAC fans to effectively push air through the filters at the high end of the MERV rating scale.

What MERV Rating Do I Need for Furnace/HVAC?

If you use a filter with a too-high MERV rating in your home HVAC system, it could have the effect of using a dust-clogged filter – air struggles to push through, which puts accelerated wear on your system’s fan and other components. This leads to more frequent service and repairs.

To make more thoughtful decisions about what type of filter to use in your home HVAC system, start by checking your system’s documentation for a maximum MERV limit. Using filters above the MERV limit will hurt your energy efficiency immediately and will likely cause more expensive problems down the line.

Once you know your available range of MERV ratings, consider whether there are signs you might need more filtration than you currently enjoy. Are there allergy or asthma sufferers at home? Do you have a shedding pet? Does your home seem abnormally dusty? If the answers to any of these questions is yes, you may be able to find some relief by upgrading to a filter with a higher MERV rating.

MERV Filter Ratings and Application

MERV ratings range from 1 to 20. In residential HVAC systems, filters in the 1-4 range are most common, but it’s not unheard of for homeowners to use filters with MERV ratings as high as 8 in typical household systems. Here’s a quick rundown of what filters of various MERV ranges are capable of filtering out of the air:

MERV Rating Particles Captured Common Uses
1–4 Large particles: dust, dust mites, pollen, carpet fibers, insects, lint Basic residential HVAC; mainly protects equipment rather than improving air quality
5–8 Mold spores, pet dander, aerosol spray particles, finer dust Most homes; light commercial and industrial settings
9–12 Lead dust, auto emissions, welding fumes, humidifier dust, larger bacteria Higher-end residential, commercial buildings, some hospital labs
13–16 Bacteria, smoke particles, sneeze droplets, oil mist Hospitals (surgical suites), smoking lounges, areas requiring high filtration
17–20 Viruses, carbon dust, ultra-fine smoke particles Cleanrooms for pharmaceuticals, semiconductor manufacturing, and sensitive electronics

Common HVAC Filter Types with Pros and Cons

 
Filter Type Key Features MERV Rating Pros Cons
Fiberglass Filters Affordable and disposable 1–4 Low cost, easy to replace Very low filtration efficiency; poor for allergens
Pleated Filters Higher efficiency for allergens and dust 5–13 Better air quality; captures smaller particles; widely available Higher cost than fiberglass; may restrict airflow if not changed regularly
Electrostatic Filters Attract particles using static electricity Varies (typically mid-range) Washable options reduce waste; good for dust and allergens Higher upfront cost; requires maintenance (washing)
HEPA Filters Captures 99.97% of particles ≥0.3 microns Equivalent to MERV 17–20 Exceptional filtration; ideal for allergy sufferers; improves indoor air quality Expensive; may require HVAC system modifications; can restrict airflow

Specific Air Filter Models

  • The 9223 A889 20402 air filter is commonly used in specific HVAC systems and air purifiers. It effectively captures particles like dust, pollen, and pet dander, enhancing indoor air quality. 
  • The 22U-04-21261 is a filter element designed for use in Komatsu machinery, specifically in their construction and heavy equipment lines.

While the highest-rated MERV filters are rarely necessary for most households, understanding indoor air quality services is essential. Upgrading your filter and pairing it with duct cleaning services can significantly improve air quality, boost HVAC efficiency, and reduce allergens, dust, and other contaminants in your space. To get started, reach out to an HVAC professional near you today,