How much heat does a 400w HPS bulb disapate?

Well, I'm going to have a growbox thats 4 ft long x 2.5 ft wide and 3.5 ft tall
I intend to have a 120mm computer fan connected to a carbon filter for exhaust
and a smaller 80mm fan for intake
what im wondering is with a Bubbleponics system in here and the space allotted am I going to have heating issues?

This is a TV stand so the light would be directly under where the light is

the light is gonna be an HTG supply 400w HPS bulb w/reflector and ballast.



Like I said I'm wondering if im gonna have heating issues?
I've seen DIY cooltubes but havnet found a good tutorial, can anyone point me towards one?
and for Lowryder Hybrids/lowryder is it good to have an HPS throughout the grow, or an MH bulb? as in which would be better for ending yield?

you might have heat problems as well. try bigger fan for intake

When you order your light either get the "euro" reflector or the cool tube.

They both have 6 in holes on both sides where you can attach ducting to. This makes it much easier to ventilate and control the heat because the light is encased in glass, meaning it is harder for the heat to escape.

3 1/2 ft tall is not tall enough for a 400 watter. Your plants would have to stay under 2 1/2 ft tall including the pot. It can be done but you'd want to do some Lst'n or screen of green.

I realized that so I figure I'd be growing lowryders and its hybrids, which stay very short

also this is in a homemade bubbleponic system, which I'm using a container that is very short in height

originally I was gonna use T5's but figured for the same price, if i can get away with gettin a 400 then i should do so, but if heats gonna be an issue, would it be wise to maybe get a smaller wattage hps? or stick to T5's?

there's a good amount of heat coming off a 400 watter. I suggest a inline fan like a squirrel fan, not a can fan. I heard the Homedepot inline fans are noisy and aint as strong as their rated. I had a computer fan venting my light, but I changed it to a Hydrofarm active air blower 265 CFM. Much better, my cab is a lot cooler then before.

i got a can fan and it seems to be doing its job. Its not forceful but it pulls the air.

ok, so if i had made ducting to suck air through a cool tube, than I would no longer have heat issues?

and also, if i had a cool tube, could my light be a lot closer to the plants? if so how much closer?

7evendayfall said:

ok, so if i had made ducting to suck air through a cool tube, than I would no longer have heat issues?

and also, if i had a cool tube, could my light be a lot closer to the plants? if so how much closer?

Click to expand...

Yes, it will elimnate alot of the heat

Yes, you could put you light closer. I would start out with 12in, then see if you can go closer.

hmm...I think ima rig up a cool tube for like...real cheap. WITH quality...DIY thread to come...