Understanding Your Air Filter’s MERV Rating

The minimum efficiency reporting value (MERV) is a standard developed by the American Society of Heating, Refrigeration and Air Conditioner Engineers (ASHRAE). The MERV rating is an indication of an air filter’s efficiency. It allows you to select filters based on how well they target and remove particles from the air.

Most air filters receive a MERV rating of between 1 and 16. The higher the rating, the better the filter is at removing small particles from the air. Here’s a breakdown of the various MERV ratings:

MERV 1-4

Filters in this range are designed to target larger particles, like dust, pollen and carpet fibers. Along with being effective for larger particles, these filters are more affordable.

Fiberglass filters fall in this MERV range, but they’re better suited to protecting HVAC equipment than improving indoor air quality.

MERV 5-8

Filters rated between MERV 5 and MERV 8 target smaller particles like mold spores and cement dust. Filters in this range are ideal for the average household and are 20 times more efficient than standard fiberglass filters. Polyester and pleated air filters are in this range. They provide a balance between effective particulate removal and good HVAC system performance.

MERV 9-12

Filters in this range target even finer particles such as auto emissions and milled flour. They provide a healthier breathing environment and are recommended for allergy and asthma sufferers.

MERV 13-15

These filters remove a greater range of particles, including ones as small as bacteria.

MERV 13

and higher filters are recommended for people suffering from respiratory illnesses. They’re often used in commercial buildings and in hospitals. These filters can reduce an HVAC system’s efficiency due to their density, so first consult an HVAC pro before upgrading.

At Sobieski Services, Inc. our goal is to help our customers in Delaware, Pennsylvania, Maryland and New Jersey learn more about energy and home comfort issues – especially HVAC and plumbing issues – so that they can save money and live in healthier, more comfortable homes.

Photo Credit: morebyless via Compfight cc