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Decode HVAC Air Filters

Decode HVAC Air FiltersWhen shopping for an HVAC air filter, do you understand what the numbers and acronyms on the packaging stand for? Not all rating systems are the same on all filters, so it may be difficult to figure out what they mean. Here’s a primer to help you decipher.

What the Rankings Mean

In North America, the HVAC industry rates air filters on the MERV (minimum efficiency reporting value) scale. The MERV ranking indicates how dense and how effective the filter is likely to be in capturing ever smaller particles. Here’s a basic breakdown of the MERV system:

MERV 1–4: A basic fiberglass filter that captures only the largest particles (over 10 microns).

MERV 5–8: A more effective residential and commercial filter, capturing particles as small as 3 microns, including dust mites, pollen, mould and mould spores.

MERV 9–12: A superior residential/commercial/hospital filter, these are often made of polyester/cotton fibers, are pleated and do a capture particles as small as 1 micron.

MERV 13–16: These filters are dense enough to capture bacteria. smoke and other particles down to .3 microns in size. They’re designed to filter systems in hospitals and in surgeries.

MERV 17–20: These ultra-dense filters can capture particles smaller than .3 microns, including viruses and carbon dust. These filters are usually designated as HEPA, or high efficiency particulate air filters. They are usually designed for medical, pharmaceutical and electronics settings. HEPA filters are typically not recommended for use in residential systems without special modifications, as they impede airflow and could cause equipment malfunctions.

Other Ratings

Some air filters may be rated by a different system. The MPR system, developed by the 3M company, stands for Micro-Particle Performance Rating. The filters are rated on their efficiency in capturing particles less than 1 micron in size.

The FPR (filter performance rating) was developed by Home Depot, and uses a color code and number scale of 4–10. It is similar to the MERV rating.

To learn more about which kind of HVAC air filter to use, contact Arpi’s Industries. We’ve served our Calgary customers for more than 50 years.

Our goal is to help educate our customers in Calgary, Alberta about energy and home comfort issues (specific to HVAC systems). For more information about HVAC air filters and other HVAC topics, download our free Home Comfort Guide.

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