I have three 12"X12" intake vents in my house. I am curious: is it possible to attach a small furnace filter to the inside of an intake vent to have another barrier against dust? Are there filters specifically designed for intake vents? What will happen if I take a regular filter (e.g. Filtrete 12 In. x 12 In. x 1 In. Micro Allergen Reduction Air Cleaning Filter in Red - 9810DC-6 at The Home Depot) and duct tape it to the inside of the vent cover? Thanks.