Intake question.

[Hello12345]

I know there are a lot of similiar topics on this forum but ive browsed most of them and none are really specific to my question so here goes:

ive got a small bedroom converted into my grow space, approx 2mx2m.

Out take is a 6" rhino.

2x desk fans circulating air inside the space.

Only intake i have is a small hole in the roof pulling air in aswell as the nooks and crannies u get with any room which i assume is letting air in too. Im seeing massive negative pressure from outside the room, everything being sucked in like a vacuum basically which is why i just want to make sure my "passive intake" is enough or should i start using my 4" fan from my old filter to pull new air into the room?

THanks in advance

[Tabbatha]

How big is your inlet hole in the roof?


Negative pressure is good, but you don't want to put undue stress on your 6" fan.

If it were me, I'd either make a bigger hole or add a small fan.

:)

[Hello12345]

the hole is 4" mate, basically the exit for my old 4" ducting.

Like i said i have the spare fan anyway so if its going to help by bringing in some extra air, i might aswell do that?

[Tabbatha]

Hmmm..


I had a 6" rvk with passive intake of about 8".. in a 1.2m tent.. and had no problems with too much neg pressure.

I'd say that you don't NEED to do any more work on airflow, but it certainly won't harm matters to add it if you already have it, in fact it will help to encourage a more even airflow, and reduce the workload on your 6" fan.

My final answer is to add it.

:)

[robinhood]

Also I was always told to add intake towards floor of room - i.e. let it rise up the room and into extraction.

[Tabbatha]

Also I was always told to add intake towards floor of room - i.e. let it rise up the room and into extraction.

Although that's entirely accurate, if the fan is pointing directly downwards from the ceiling it should end up creating a sort of 'U' shape airflow.

:)

[robinhood]

Yes lol if it has enough oomph. Will it cool the canopy? If so then thats all that metter i suppose

[Hello12345]

I was just concerned that too much was being sucked out the room with not so much being put back in, since its a big powerfull fan i didnt know the effects it would have.

Extra stress on something that costs so much isnt something i want to deal with lol so i think ill end up using the intake fan and take some fresh air in

[Tabbatha]

Yes lol if it has enough oomph. Will it cool the canopy? If so then thats all that metter i suppose It should do, yes.. UNLESS, of course, that the downward flow is going over the lights, in which case it'll be blowing warm air onto the canopy.
The 'U' flow patten should keep the heat moving upwards overall.. and will also act as air movement for the leaves etc, provided it's away from the lights.

:)



I was just concerned that too much was being sucked out the room with not so much being put back in, since its a big powerfull fan i didnt know the effects it would have.

Extra stress on something that costs so much isnt something i want to deal with lol so i think ill end up using the intake fan and take some fresh air in My thinking, exactly. The 6 inchers start getting pricy, don't they. Well worth looking after them to save costs later.

:)