400W HPs + Heat Concerns

Yo everyone,
So i recently bought a 400W HPS Bulb (with ballast) and a large shader. I currently don't have any method for air flow - my question is, do I need one (how hot will it get in there)? The growing area is under a wooden stairwell (and there are quite a few carpet off-cuts in there) and is roughly 5 feet deep, 4 feet wide and 4 feet tall.
Cheers,
Jono

my 400w in a large wardrobe no ventalation in the room with a desk fan was on average 86f which was little to high so switched to cfl.

Meh 86F isn't too bad I guess. So you had no ventilation?

none mate my room is in the middle of the house , theres no windows at all , used to wake up sweating from the heat lol , so long as u got a window ull be fine mate.

I just had a thought - could I use a bucket of ice to keep the heat down?

No it's not in my room its in quite a confined cupboard

You could make a vent somewhere or get a little air con unit. Get a temperature probe and check your temps with the light on I think you will find your temps may be a little too high.

A couple of PC fans can be used for intake and outtake but this will not deal with the smell as a carbon filter and inline fan would.

Having stable temps you can rely on is a blessing when sorting out your first few grows ! I highly recommend some solid flow of air, it also replenishes co2 and if you have a nice breeze in their strengthens the stalks making your plants able to carry more weight.

Mouse

u can but it wont help for long. ventilation is not only important for heat reduction but also reducing stale air. ocilating fans will help and should be used (think of it like a cool breeze on a hot day). 86 is kinda high. remember when the temps are high stress happens, bugs happen, crops get ruined. humidity during the flowering stage will also hurt you with powdery mildew and bud mold. you could use a radiator style vent for an intake or mounted to your light (if its able to be aircooled) and pump hot air inside through it. running chilled water through tubing around the light/canopy will also help as a cost efficient way to cool the room. a dry ice container with a small cpu fan on the side (not touching the dry ice only aerating it) may help and will also provide extra beneficial co2 for your room. my recommendation is to use a small a/c, use intake and exaust, OR a vented through aircooled light. (try not to use a/c in conjunction with intake and exaust venting as it will cancel out the a/c)

Cheers for the solid advice guys - I just put in an oscillating fan and that seems to have made a good difference.

you should def invest in an inline fan. even if you dont have an air cooled hood it will replace the stale air as well as circulate while removing the heat. you can find plenty of cost efficient ones. try htg supply.com. its an investment that pays for itself. trust when i say your better off with temp control than without it. if temps get too high you may not be able to see the damage until its too late. wilted leaves are only the beginning. try burnt tops or mutated growth at your highest cola's. thats what i dealt with my past grow and had to chop early. good luck with it

Get proper ventilation, not only for keeping the bulb cool but for getting rid of the smell when it gets down to flowering. Do it right the first time. I guarantee you, you'll spend more $$ thinking up ghetto ways to cool and get rid of smell than you would if you bought an inline fan & carbon filter.

under a staircase that's only 4' tall. That bulb will get way hot and make the room above 90 I can guarantee you that.

Trust me, get an inline fan, carbon filter

GetDemBuds said:

I just had a thought - could I use a bucket of ice to keep the heat down?

Click to expand...

You'll be creating a new problem... Humidity. Just seal the area off and get an inline fan shovin the air to another room.

mr2shim Has got it nailed !

Mouse

SirLancelot said:

You'll be creating a new problem... Humidity. Just seal the area off and get an inline fan shovin the air to another room.

Click to expand...

+1 I did that with my first grow, because I was using a computer fan to cool/remove smelly air and push it through a piece of carbon filter. Did not work out that well at all.

Thanks for the advice Hoenhiem

Using an oscillating fan atm. Doesn't seem to be too hot in there

You need to get a thermometer. At 90 growth stops. You need to know the hottest/coldest time within a 24 hr period. Get one with humidity too and this will tell you all you need to know about your environment, considering you have an oscillating fan already to prevent hot/dead spots in the air. Something tells me you're going to need to an exhaust fan, though. And like shim said; a carbon filter is a purchase you definitely will NOT regret!