Surprising HEPA Compare: LINNIW Filters for 3M Systems… Fresh Air, True Test… We recently swapped out our aging 3M Filtrete filters with the LINNIW 2-Pack F2 A2 True HEPA replacements, eager to test their performance. The installation was straightforward—no compatibility issues—and the seals felt snug. Running our 3M system with the new filters, we noticed an immediate difference in air quality. Our space felt clearer, and the unit ran quietly without overworking. The dual-ply True HEPA design seemed to capture particles effectively, matching or even exceeding our original replacements. After a month, the filters show no visible wear, and our energy bill hasn’t budged. Overall, we’re impressed. These LINNIW filters are a reliable, cost-effective way to maintain fresh air in our 3M system.