Nordic Pure <b>MERV 12 Pleated AC Furnace Air Filters</b> provide exceptional filtration for both home and office environments. Each time air passes through the air filter, lint, dust, pollen, bacteria, pet dander, dust mites, mold spores, smoke particles, virus carriers, allergens and other contaminants are removed.<br> <br>MERV 12 filters are comparable to air filters with the rating of MPR 1500-1900 or FPR 9. While different companies use different rating systems, Nordic Pure chose to follow the industry standard MERV, as developed by ASHRAE. <br><br>Nordic Pure furnace air filters are manufactured using a heavy duty, moisture resistant beverage board frame. The air filter media is electrostatically charged to attract unwanted particles and will not promote the growth of bacteria or mold on the filter. br><br>For fresh, clean air, we recommend changing your filter every 1-3 months, depending on your unique environment. People with pets or those with allergies, asthma or other illness should change their filters more often. Changing your filter regularly improves indoor air quality and helps your HVAC unit perform more efficiently. <br><br>lmportant Note: Almost all air condition filters have a different Actual Size than the Nominal Size printed on the side of the filter. It is best to measure the exact size of your filter and compare it to our Actual Size to be sure your filter fits.