Quick question about cooling a 400 watt HPS

i have a sun systems 2 400 watt hps that has a place to hook up duct on the side and maybe the top too.....i have cool air running into my grow room through an 8" duct with a 200 cfm duct booster fan that spits air out about 18 inches from the ground which keeps the room around 73 - floor, 80 - 2 feet below light, over 90 - 4 inches below the light.....if i attach one of these cpu fans to the side of the light (screw or adhesive) just to blow some air around the bulb and then add another fan to the top to suck air up away from the lamp towards my exhaust duct, would that lower temps some?.....im very interested in this concept because i am on a budget and am looking on surpluscenter.com at dc fans.....i believe i'll go to walmart and pick up an adapter.....thanks for any advice.....check out my grow journal to get a better idea of what my setup is if it helps any

raulhawkins718 said:

i have a sun systems 2 400 watt hps that has a place to hook up duct on the side and maybe the top too.....i have cool air running into my grow room through an 8" duct with a 200 cfm duct booster fan that spits air out about 18 inches from the ground which keeps the room around 73 - floor, 80 - 2 feet below light, over 90 - 4 inches below the light.....if i attach one of these cpu fans to the side of the light (screw or adhesive) just to blow some air around the bulb and then add another fan to the top to suck air up away from the lamp towards my exhaust duct, would that lower temps some?.....im very interested in this concept because i am on a budget and am looking on surpluscenter.com at dc fans.....i believe i'll go to walmart and pick up an adapter.....thanks for any advice.....check out my grow journal to get a better idea of what my setup is if it helps any

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not sure how your set up now but this is a good setup.

I have a simular set up with a fan on the floor just outside my grow room sucking in cool air through flexable duct into my light. I put an elbow on the other side of the light aimed toward my carbon filter and fan. It works great.

thats sounding pretty complicated -- i got a lot to learn lol

here are some pics to give a better image

i have an 8" inline duct fan sucking in air from outside....the duct runs to a window for fresh air and keeps the room pretty chilly when the light is off


the duct shoots out air a few inches above the ground


i have a small oscillating fan on the ground that blows air around


i have a bathroom exhaust fan that sucks air out of the room at 50 cfm


on the light, there are two vents...the side one detaches and u can purchase a piece to connect duct with....the screw holes on both vents are 4" apart


if i get two computer fans and attach them to the light with some sort of adhesive, would it help lower temps any around the light?



i was thinking about having a fan on the side to blow air in towards the bulb and have the one on top suck air away from it and blow it towards my exhaust fan....i dont want to use any duct work, just have the fans by themselves like inside of a computer

im thinking of purchasing 2 of these and wiring it to a 12vdc adapter
https://www.surpluscenter.com/item.asp?UID=2009121621104683&item=16-1380&catname=electric

does that make it any clearer?....any suggestions?.....thanks

the bathroom fan is not enough to exhaust that kind of heat. you want to maintain a good temp when lights are out. try and keep a 10 to 15 degrees difference between lights on and off. i thought you had a cool tube set up but you don't, so your going to have to come up with a monkey job to suit your grow area. there are many ways to move the heat out and away from the top of your plants. i myself just hang a fan just at plant top level to blow the heat away.

mygirls said:

the bathroom fan is not enough to exhaust that kind of heat. you want to maintain a good temp when lights are out. try and keep a 10 to 15 degrees difference between lights on and off. i thought you had a cool tube set up but you don't, so your going to have to come up with a monkey job to suit your grow area. there are many ways to move the heat out and away from the top of your plants. i myself just hang a fan just at plant top level to blow the heat away.

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im hoping that the cpu fans will get a current going towards the ceiling...might create a vaccuum and solve any humidity problems too....who cares, they are only $5, if they dont end up working then i will think of something else....worse comes to worst i will purchase an inline fan with some real power....i was worried about hanging alot of weight on that shelf....the bathroom fan should work, i just have to find a way to get the heat up there....thanks for the input

What about using those little clip on 6" fans i got one blowing across the canopy on each of my lights taking air up to the top of the room although my exhaust fan is bigger as well

swordfish984 said:

What about using those little clip on 6" fans i got one blowing across the canopy on each of my lights taking air up to the top of the room although my exhaust fan is bigger as well

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i plan on getting another oscillating fan, a bigger one.....im gonna try the cpu thing

raulhawkins718 said:

i plan on getting another oscillating fan, a bigger one.....im gonna try the cpu thing

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i veg in a bathroom also and the fan dosn't work for me. i have two windows in my bathroom one for intake and the other for exhaust.