Hello All! I just installed a new bathroom fan. Everything is connected well and the fan is working. 4" duct work, 110cfm fan. Anyway, It does actually suck air up but I noticed air is shooting back down through gaps inside of the fan housing (NOT outside). My question is ... would it be ok to caulk gaps inside of the exhaust fan housing? It seems like it would be ok, but then I started thinking about what if it is too much air for the 4" duct work and the air is simply pushing back out? I have seen a couple of people online say to fill in gaps with caulk but most of the things i have found only deal with sealing outside of the housing dealing with drywall gaps. Thanks!