Filterbuy 13x21.5x1 Air Filter MERV 8 Dust Defense, Pleated HVAC AC Furnace Filter Replacement, 2-Pack

We decided to filter at the cold air returns rather that at the air handler. The goal was to reduce the amount of dust in the house. The 12x12x1 filters fit the returns perfectly. We've noticed no difference in air flow. It's too early to determine if there is less dust. The filters are of high quality. If the change we made in filter location works the way we want, we'll definitely be purchasing more from Filter Buy.

I had a new unit installed and the fan runs continuously. But my electric usage is down. I have four cats and one large hairy dog; live in a dusty environment and need to change filters every two weeks. The big box store was charging almost a dollar more for a MERV 5 filter and I had to bend them to get them to fit, which left gaps along the sides. These filters fit and they cost quit a bit less than what I would have paid for a MERV 8 in store.