how to build intake for fan????

johndoe12345678

Well-Known Member
right now i have a furnace filter right under my 12inch vortex fan directly above a 11inch hole i cut.. the filter gets alot of dust accumulated on it frequently how to i modify it so i have good flow with out the constant dust..should i just build a long box put filter on bottom and fan on top so the air isnt resricted to a 11inch hole?
 
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