Ventilation query

AcidFB

Active Member
Hi. I am in the process of setting up my first closet and have a couple of ventilation questions I need help with. I have built a 6'x4'x4' closet with a 200mm hole in the roof for my exhaust fan and have a 250mm hole in the bottom right side for the intake. My exhaust fan is a simple 268cpm fan /w 3 metre of ducting and I have yet to purchase a fan for intake. I have 600w HPS light and will have an oscillating fan inside as well to help with airflow.

So my questions are:
Is it ok if my intake hole (250mm) is larger than exhaust hole (200mm)?
Is it sweet to buy 2 x 268cpm fans and just spin 1 for intake and use other for exhaust, or should one be weaker than the other?
Do you think my fans will be sufficent given the 600hps and size of room?


thanks in advance
 

AcidFB

Active Member
Yeah I checked out some greenhouse sight that calculated fan needs and surprisingly mine was ok. Research does wonders :)

thanks
 

AcidFB

Active Member
Alas I still have one question about airflow.

I have 2 x ball bearing fans - 1 is 334cfm and the smaller one is 157cfm
My closet is 96 cubic feet (6'x4'x4'). Apparently I only need around 115cfm fan to exhaust, though Im not sure if light heat has been taken into consideration.

Is it best to have the larger 334cfm fan as an intake and the smaller 157cfm fan as exhaust? or the otherway around...

please help, Im confusing myself :?
 

VictorVIcious

Well-Known Member
You will want to air cool a 600 watt light separete from the rest of the air handling system. No, they did not take the heat from that light into account when they told you you would be fine with that. VV
 

Emosdoom

Active Member
I've always read that you want the stronger fan for exhaust. The reason is that it creates a negative pressure in the room and helps contain odors better.
 

TheOrangeJuicer

Well-Known Member
My room is 4' W x 4' H x 1'9" deep. I have a 600W in there with a 175 CFM fan as an exhaust fan. I also have a Wal Mart Stanley Blower fan for 40 bucks that is used as intake.. I have the stanley sucking air from outside the house. You have more room than i do so im sure you wont have a problem.

I have mine set up to where the stanely fan is just blowing air from outside into my box and then i have the 175 CFM fan connected to a carbon filter and sucking air through the filter through the light cooltube outside of the box and it works great.

If you had the 330 CFM doing what my 175 CFM does im sure your gonna be ok... Just have your smaller fan as an intake to get fresh air into the box...

hope this helps.
 
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