The 3M Filtrete MPR 1000 Micro Allergen Defence is a 1-inch deep pleated filter. The 20″x25″x1 version we tested contained 21 pleats. It fits most filter slots and housings. While it can’t compete with some deeper filters, for what it is (a 1-inch deep filter), it offers above-average filtration performance.

Rated at a Filtest permeability score of 5.9 (higher means better), the Filtrete MPR 1000 pressure-delta is considered high. A higher pressure delta would put more strain on your furnace (or AC) blower fan, which would lead to higher consumption of energy and would potentially shorten the life of your equipment when compared to filters with a higher permeability score.

As with other filters in the 1-inch deep category, this filter requires frequent replacements (which we are not big fans of).

As for the Filtrete MPR 1000’s filtration performance, its sub-micron performance is less than mediocre (47.4% @ 0.3-1µm) and OK+ at the 1-3µm level (78.9%). The performance of this filter at the 3-10µm level is quite good (88.6%). Please note that Fltest.org does not incorporate this category (3-10µm) into the weight of our total score.