Nordic Pure Pleated Air Filters MERV 14 are made of electrostatically charged synthetic materials that attract and capture most airborne particulates in your home. Each time air passes through a Nordic Pure in. Pleated furnace filter it removes contaminants from the air. All Nordic Pure in. Pleated air filters are manufactured using a heavy duty moisture resistant beverage board frame with a metal mesh support grid bonded to the in. Pleats. MERV 14 furnace air conditioner filters are comparable to HVAC filters with the rating of MPR 2800. It is important to note that because of this high filtration and air flow restriction HVAC systems should be rated to handle filters of MERV 14 and above. Nordic Pure MERV 14 air filters work great in newer high efficiency systems that use HEPA filters. The effective life of your AC air filter depends on both the inside and outside conditions in which you live. We recommend that you change your air filter every 30-90 days to maintain maximum efficiency and economy. bImportant Note:/b Almost ALL furnace filters have a different \ actual size\ than the nominal size printed on the air conditioner filter. It s best if you measure your air filter for the Exact size and compare it to our \ Actual Size\ - and then you can be sure your A/C air filter fits.