How hot would a 400 watt hps light get

if the space was 5 feet high 4 feet long and 3 feet wide? how many fans blowing out would i need? i have a window to have it blow out at all times is on enough for that space?

use a vented hood and one fan for light and one for plants should do.

Get a hygrometer. Check ur temps, than figure out how to keep 80 or below.

I grow with 400 hps, and my dimentions are 2 1/2' by 2' by 8'
and I have 2 16" osilating fans in there one blowing straight up to blow the hot air out the hole in the ceiling and and one blowing over the plants and a cyclone booster on my light and I still can't close my door during the day. They get pretty warm.

-hardroc

hey hardroc is your hps light ballast inside the grow room or is that just the bulb?

sickstoner said:

if the space was 5 feet high 4 feet long and 3 feet wide? how many fans blowing out would i need? i have a window to have it blow out at all times is on enough for that space?

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My grow space is actually a little smaller than yours even and I am using a 400 watt HPS as well and keeping a consistent temp of 75-78 F. with just 2 120 mm computer fans sucking air in at the bottom and 2 of the same fans blowing out at the top. Check out my album if you want a visual.

u said u have a window ? you should be rite then just put the fan on so that its moving from left to right

Mr. StankyFingas said:

My grow space is actually a little smaller than yours even and I am using a 400 watt HPS as well and keeping a consistent temp of 75-78 F. with just 2 120 mm computer fans sucking air in at the bottom and 2 of the same fans blowing out at the top. Check out my album if you want a visual.

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Nice and your ballast is in there two??

heat inside the room depends also on the external temp, if its cold outside the room it'l stay cooler inside so its a case of seting it all up and monitoring the tems and altering the room to suit. this is bes done before germination.

too many variables to say exactally how warm a room will get with just the lamp and room size. Where's your ballast? Are the walls of the room insulated? is the room sealed? etc...

im lovin all this 400watt hps small space grows. il be getting my ballast n fixture in 2 days. (already have the bulbs). my space is [closet] approx... 5feet high / 4.5 feet long / 2.5 feet wide. im going to fire up the light with the heat for that room compleatly off ( IT GETS COLD) and see how it does. (while my 1 plant is elsewhere getting light. shes going to turn into a beast once under hps ) and i have fans n stuff so il be working on it and post up a thread. lookin foward to this. all your grows sound/look great btw!

I've got one in a 6'x2'x3.5' 1/2 closet with one computer fan and it's doing great!
You should be good w/ a fan or two. But I suppose it all depends on how hot your house is too. I keep my heat at a toasty 60 degrees. Haha.

my local hydro store guy seems to think the 250 is almost half as cool as the 400watt , i think hes going by how many watt=heat output, i just got a 250hps installed today with only 1 exhaust fan thats probly twice the size of a pc fan and my setup is only 3.5 foot high/2foot wide/1foot deep , he also said closet growers only need an exhuast becuase as will as taking the hot air out it sucks air in thru the crackes on the corners.