Will 400w cool tube hps be too hot?

[estranged]

Well the gf decided she wants the closet back,, since i havent gotten around to buying another dresser for her clothes like i said i would,, :0

so we decided its time to build a grow cab, box, whatever,,
this is just for flowering,, will build another one for veg,,

but couple questions first,, (as always)

1. have good plans for 2'depth x 3'width x 5'height
so was thinking minus roughly 1' for pot and 1' for lights , that should mean i can grow roughly 3' high,, or do i gotta allow 1' for light and 1' for distance of light from plants so mean only 2' high?

2. With 30sqf can i put a 400w air cooled Hps in there with passive air intake from outside the closet and a 100mm 12vdc computer fan (roughly 30cfm)for exhausht outside the closet on the tube alone,, then two more 12vdc fan for exhaust of the room and passive intake,, which should clear the room 2 times a minute (or once a minute if only running at 12vdc for noise reduction)
would this work?or would a 400w be too hot for that?

heres a rough sketch i quickly made on paint,, lol

(forgot to add chains for hanging light and what not but you guys get the idea)
please chime in with advice,, should i just use 250w but there the same price as the 400w so i wanna use the 400w if can,,

 

[Damagoman]

Looks good to me.
Go with the 400.
Just have to set it up and run it sometimes to see if it works.

 

[rugdoc]

30 cfm for the light? It might be too little, but I am no expert. Good luck and I hope you get lots of green!

 

[estranged]

well i dunno either,,lol
but the way i see it ,,i read its recommended that the total volume of air in a grow space should be exchanged 3-5 times a minute for optimal results when dealing with HID lighting. no mention of cool tube applications,, so removing the air 2 times per minute is not optimal but most likely work,, then add in cooltube likely be exchanged 5 -6 times per minute,,
its gotta work!!
does'nt it?? ,,lol,,

but i think damago said it best ,,
sometimes just gotta do it and see,,
worst case ,, spend some money on "real" ventilation,,

its a go!! light has been ordered !!
hmmm ,, its gotta work doesnt it,,.....

 

[Damagoman]

total volume of air in a grow space should be exchanged 3-5 times a minute for optimal results

2-3 times an hour is plenty

 

[bmarcb]

CFM for heat reduction can be tricky. once you go into HID lighting it might not be as easy a the 3-5times a minute formula. If you use a cool tube or reflector, you could use a seperate fan to cool it and then 150 cfm should cut it for your room. Otherwise 2-3 times/hour wll have you way hot in there i.e. your room is 30cu.ft. this means that @ 2-3time/minute youd need around a 90-100cfm. Get yourself a nice 4in inline fan like vortex or can fan and youll be good to go. 2-3 times an hour would be a half pc fan cool a 400w...

good luck!!