Filter Replacement Acronyms: MERV, MPR, and FPR: Cutting Through the Clutter of HVAC

If you own a forced air heating system (one with vents and a furnace rather than a boiler and baseboards), one of the most important maintenance tasks you have is to check your air filters often – at least once a month during heating and cooling seasons – and to change them when they’re dirty.

That’s because a clogged air filter can cause your HVAC system to overwork, which will cost you far more than the replacement price of a filter in the form of higher bills, more maintenance, and a shorter life for your equipment.

But when it comes time to buy your replacement filter, you may find yourself encountering a series of acronyms that make a simple task seem confusing. But don’t worry – we’re here to help.

The FSi quick guide to home filter acronyms

Three common terms you might hear when shopping for a replacement filter for your HVAC system are MERV, MPR, FPR. Each term describes a filter system designed to clean your home air, and each uses a scale to define the size of the filter holes (higher numbers = finer filtration. Think of it as a tighter weave).

The only difference among the three systems is who manufactured them:

• MERV, or Minimum efficiency reporting value, is a measure developed by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE); MERV ratings range from 1-20.
• MPR, or Micro-Particle Performance Rating, pertains only to products developed by the 3M company; typical MPR ratings range from 300 to 2200.
• FPR, or Filter Performance Rating, is a filter rating system developed by Home Depot for the brands sold through its stores, including Honeywell; it uses a 1-10 rating scale.

Common MERV, MPR and FPR values

Here’s a table of equivalent MERV, MPR and FPR ratings for common residential usage (higher-valued filters are often used in hospitals and operating rooms, but are not necessary for home use):

Need help with air filter replacement or furnace or A/C maintenance in western MA? Contact the heating and cooling experts at FSi today!