Second Grow, upgrading my box! pics!

After a sad attempt with CFL's (my fault, not the bulbs), I decided if I was going to get serious about this, I might as well go all the way.

My current grow box is 12"X12"X37". It had 6 28W CFL's (2 in pic). As I have ordered 10 Aurora Indica seeds from nirvana, I decided it was definitely time to get serious on the lighting.. so I ordered a 150W HTGsupply remote ballast HPS system. I will be increasing the Length of the box by 4" (don't ask how.. lots of ducktape and spare cardboard).

Since Heat is my primary concern going to such a large hot light in a small area.. I also ordered a 4" inline exhaust fan, and 8 feet of 4" ducting.

This is the setup I am building, I am looking for any input from people from long experience with the 150W HPS.. I have been very worried about heat, but I figured with 120CFM or so in and out going all the time.. thats gotta completely change out the air in that box like every 30 seconds or something..

This is in a normal size closet linked to a room with a 5000 BTU window unit.. so the temperature stays around 68 all the time. Think I can keep it cool enough?

Key to the pictures:
1. 150W HTGsupply HPS (remote ballast)

2. 4" outtake duct, leading to 4" inline exhaust fan

3. 4" computer fan, blowing across light towards the exhaust outtake

The fan at the bottom of the box is a 4" computer fan blowing into the box, with some homemade ducting.

Also lining the entire inside of the box with Mylar.







Anyways.. I'm about to explode now that all this is ordered, it had better come quickly. I will of course update later this week when it is all put together, but I was really wanting some input on possible heat issues. Have I gone far enough with venting?

Thanks, Blah~

definetely a good upgrade. i just switched out my cfl's that i had used for 2 harvest for a htg 400 watt hps. it got to me on the west coast in a week. so it wont be too long.

i think with your normal temps being so low and the fan you should be ok on your temps.
I would lose the tin foil in your room and either paint it white or line it in mylar. either of these two will be far better at reflecting and tin foil can cause hot spots to develop in your room.

looking good so far, good luck

I live in florida, I grow in my bedroom closet that has no air conditioning. It's already hot here, a few days I've come home and it's been in the mid nineties in the closet. To make a long story short, it didn't affect my plants at all. As a matter of fact I was worried the heat would give me a bunch of males, ended up with six females out of nine plants. They are now into week four of flowering and doing nicely. I have a computer fan, 90 cfm, venting directly into my attic another sitting on top of my fixture to move the hot air from the fixture and now a tower fan in front of my closet with the air on in my bedroom. The closet door now stays open until lights out. Just don't have your light so close you're burning your plants and keep lots of air circulation going on and I think you'll be ok.

Sweet, yea thats really what i was hoping for.. i figure the heat cant burn it if the air is just constantly being pumped out.. plenty of fans.

Soon as i get it all hooked up going to see what kind of temperatures i end up with with the door open and then with it closed.. see if i need another fan or intake or something.

good points heads up. make sure to keep your 150 around 12-15" away from your plant. (this is an estimate, you need to keep a 400 watt around 18-22 inches away, so i figure you can get your 150 a little closer) test the heat with your hand, if it is too hot were the light is, then move it up until it is as close as it can be while not being to hot.

also keep a fan blowing directly under the light. i have this, because i dont have a air cooled hood, and it works wonders temp wise in the canopy.

i have had my box get up to like 92 a couple times, with no ill effects, but i try to keep it around 85 or less.

good luck.

you can keep your light about 2-4 inches away if you have a fan blowing between the tops and the light.my cabnet has no intake or exhuast and only 1 fan for air circulation and my high temps only get about 84-85.but my basement stays at 68 all the time.check out my journal and youll see what im talking about.just keep the ballast out of the cabnet and the heat wont be a problem