Confined closet space, 250w hps = heat?

[Paranoid]

Hey guys, and kudos for an exceptionally informative board you got going on here. And that's why I come here for advice.

I have two separate stealthy closets, one for vegging and one for flowering. The vegging one is doing fine with fluor tubes, my problem is the flowering cabinet.

While running some heat tests prior to moving my plants over to the flowering cabinet, I ran into a slight heat problem. Here are the specs:

The closet is 20"x32"x72", completely sealed except for the exhaust and intake.
Two 120mm 75cfm pc fans; one for exhaust at top and for intake at bottom. The intake is from the room itself, where the temp stays close to 70°F. I am completely unable to have the intake tubed to a window or any other cooler source of air.
400w HPS lamp suspended in the middle of the closet

The plan was to move my two plants currently vegging into the flowering closet yesterday after running some heat tests the day before. However, after running the lamp and fans for about 8 hours, I checked in and found the heat to be just about 97°F!
I had also planned to make my own carbon filter soon after moving them over and add another fan mounted right onto the pre-installed fan on the exhaust, if that matters at all.

After some research I have found that a 250w HPS might do just fine in this closet. After some more research the decision has been made to do a ScrOG grow, so even a 150w HPS will do just fine. I'm not so interested in cfl's or fluor tubes, but my budget and location might just force me to invest in a few tubes to mount to a wooden frame.

My question to you gurus is this:
Will a 250w HPS run cooler? What kinda temps should I expect?
What about a 150w HPS?
Can I expect a small simple homemade carbon filter to increase my temps, even with an extra fan?
Could I possibly run a 400w HPS light in this situation without installing an industrial strenght fan that will ruin my sleep pattern? (oh yeah, closets are in my bedroom) ... without buying a cooltube or a closed reflector?

If I could afford to buy all these things and experiment I surely would, but my budget doesn't give me that much creative freedom.

Thanks in advance,
Paranoid.

P.S. English is my second language. Apologies for any grammar or spelling errors.

 

[sfhaze]

Hey Paranoid,

A 250W HPS is going to always produce the same heat. I have had good luck with the Haight Solid State LEDs, the PPF-400 is only 90W so would be a lot cooler. They are a good choice for cabinets.

They are sponcers, so I think a link is allowed:Haight Solid State PPF-400 LED Grow light

 

[The Butcher]

this should help you with your descision on what to but as far as lightpenetration can at some point a lower wattage light closer can provide you with more lumens then a high watt light,this can help you with your heat problem less light less heat,Well in most cases. heres the chart:
(this chart was done by:Caligrower,so big thanx)

 

[Paranoid]

Thank you for your responses. I cannot afford to place hundreds of dollars into buying a LED light, but the chart has me convinced I can do fine with a 250w hps.

 

[The Butcher]

thats what its there for.it can help you reference how high to go pn you light position.it helps me.I go back to it all the time.glad to see it can help

 

[WeedWorks]

k one quick thing was just browsing by on some information on the heat ad 250w hps vs other various watts and heads up it states clearly on that chart its meant to measure the lumes and NOT HEAT so that chart is really handy but really dosnt do much about the heat problem

 

[Screwnuts33]

Can you run an aircooled hood? Vent it back into the room the closet is in. That would drop you temps down and produce a little heat in the outer room.

 

[gunjababy]

I also have a closet grow and my size is about the same as yours. and also i am using a 400 w hps. the way i keep it cool is i run my exhaust fan through a cool tube and have it exit out the exhaust hole. my exhaust fan is only 110cfm and it works great. its a bathroom exhaust fan.