Two fans one filter? Exhaust question

I understand that it is not ideal to have your fan pushing through your filter, but I also know that it only minutely reduces the airflow. What I do not know is if it will significantly reduce my airflow if I put my filter at the end of my duct work (5ft) in the attic. The reason I want to do this is so I can add a T to the filter and have the 400 cfm blowing straight through and my 100cfm light cooling fan blowing into the T as well. I don't want to buy another filter and I'm not even sure I can get one for a 100cfm booster. So here is the set up in question: silencer > 400cfm fan > 5ft duct work > T > filter & cooltubes > duct > 100cfm booster > duct > T (same one) > filter (same one)

Thanks for the help. I haven't been on here in a while, but you guys are always clutch.

ok unless the filter was designed for a push (prefiltering the air) pushing air in a carbon filter is crazy u effectly killed the life to 3/4 months only

your set up is wrong ..............first thing in using is a Filter this is the start of the sucking point

filter.....ducting...... Y split ......duting to cool tubes......cool tubes.........ducting off tubes..... Y split with adjustable dampners ......ducting ....fan ........ducting exhust

the 400 cfm is the same sound lvl as window AC on high (96/98 dbs ) and that is with it open no ducting the sllencer is used near the venting point to dampen the sound


u need the 2nd Y duct to have adjustable dampners so u can ensure the suck power gets split evenly to keep lights cool
if u can not find the Y split with them in it then add a set on the ducting coming from cool tubes to the Y ducting that is nearest fan

oh by the way adding in the cfm boosters on a short system like that effectly increases the over all cfms so u would want a larger CFM filter to go with .......figure 50%power of extras is how i was taught to do the math

Can't do filter before cool tubes. Tubes aren't air tight and I don't want the smell sucking through that area. Otherwise all that sounds like a good plan. Not really concerned about even airflow coming through both ducts because that's going to be impossible with a 400 and a 100. One good question comes to mind though. You say it reduces filter life to 3-4 months... That's fine by me as long as it still pushes enough air through. Think it will?

I have pushed the air through a carbon filter and it worked fine. Never tried the T so I can't really say but the 400 side may cause enough resistance and presure to slow the air comming through the 100 side but you would need to test it.