A:Answer Hi BeachHouse, this unit does use a Fresh Flow air filter which is part number W10311524. Here is the link to that product: https://bit.ly/2TFn1xB The styrofoam is to remain in, and you can find the installation instructions for the air filter on page 11 of the Owner's Manual, linked here: https://bit.ly/3t5r3wb Hope this helps!