Ventilation questions

[Thaifighter]

I just got my 400 watt hps last week, ive already got a room but i need some help keeping it cool... Its running 85 day 78 night.. My room is 4' x 3' and 7' tall... I have a 6 in inline duct fan for the exhaust... what size fan should i get for the intake? Should i add another exhaust fan? And im in the south so the outside tempature is pretty hot. Thanks guys for any help

 

[puffmadizm]

is your room gonna be sealed? you have to be careful not to have more intake then outake
if it is sealed,you could use passive air intakes,the exhaust fan at the top(heat rises..) the intakes at the bottom,pulling air from the exhaust will create enough pressure to pull air thru your passive intakes

 

[Thaifighter]

Yes it will be sealed... So would a 4 in duct fan be good or should i use a couple little muffin fans for the intake?

 

[puffmadizm]

how many cfm's is your fan? bigger is better,but it depends how stealth you need it to be as far as loudness

 

[puffmadizm]

redgreenry is the guy you should talk too really,he knows way more then me,he has a thread with some great ventilation info,http://anonymouse.org/cgi-bin/anon-www.cgi/http://www.icmag.com/ic/showthread.php?t=112862 check it out

 

[Philosophelon]

Inline duct fans don't work well at even small amounts of static pressure. They are just designed to boost airflow in long duct runs served by larger fans. You will need either a squirrel-cage blower or a centrifugal blower for your exhaust to keep temps down. Also, you need a more powerful fan if you intend to use a carbon filter. I'd recommend a 6" centrifugal blower (Vortex, Can Fan, Fantech, etc.) for your exhaust, and then you can probably just use a passive intake.