K so everywhere I go I see people saying passive intakes are tha way to go and others saying you have to have a fan intake but I have yet to see any legit reasons as to why everyone juss says their opinion. So my setup is a 4x4 tent with a125w cfl for 2 freshly rooted clones im going to add another 200 w cfl in a week or so and flower with a 400 hps but tha tent has passive air slots but I taped em up and threw in a 6in duct booster btw I have a 6in inline fan valuline 435 cfm hooked to a filter. If anyone has any info on this topic please share because I would like to know if this is a good setup or if id be better of with passive intake. Srry for tha sideways pic on my phone n I can't rotate it
passive is better for smell issues.... if you don't care about smell, go forced... forcing air also causes problems with heat though, so unless you know what your doing it becomes harder to maintain temps
The problem with fan-forced intake is that it is only as effective as the exhaust can handle -- if you try to push more air into the box than the exhaust can remove then you will create positive pressure inside the grow space (which can force odor out) and will not actually vent as much air through the space as you think. Imagine a room and you are trying to put 10 people into it for every 5 who leave, pretty soon the room will be packed and there will be a line-up of people waiting to get in, whether you tell 10 to go in at a time or not. Same idea with air being forced in, it has to match the exhaust's capabilities.
Thanks for tha great answers really informative, well im running a 6 inch duct fan pushing air in prolly 150 cfm? Im not sure and 6inch valuline inline fan 435 cfm pulling air thru a filter thats inside tha tent and pushing that air towards an open window I want this as smell proof as possible so in your guys opinion wats tha best way to do it? I think from your posts itd be better without tha duct fan right?
If your intake fan is much smaller than your exhaust it can slow down your rate of exchange. The positive pressure problem will be solved but you are just wasting electricity by spinning blades that are slowing down the air that is being sucked past them. For your 6" exhaust just cut 2 6" passive intakes and you shouldn't have to worry about it.
If your intake fan is much smaller than your exhaust it can slow down your rate of exchange. The positive pressure problem will be solved but you are just wasting electricity by spinning blades that are slowing down the air that is being sucked past them. For your 6" exhaust just cut 2 6" passive intakes and you shouldn't have to worry about it. As far as the smell... If you have a decent filter you should be OK. If it becomes strong, get a bottle of ONA gell.