Yup, and adding the cardboard shroud helps keep it from stucking unfiltered air into the flow.
I think the main reason for the 4 filters is to reduce load on the fan and increase filter life. But many forced air heating systems get by with one or two filters stacked on the inlet.
Yup, and adding the cardboard shroud helps keep it from stucking unfiltered air into the flow.
I think the main reason for the 4 filters is to reduce load on the fan and increase filter life. But many forced air heating systems get by with one or two filters stacked on the inlet.