HELP with temperature control?

[Mr.Nugg]

we just got our box going and long story short our 150watt hps heats up our box to around 98+degrees with the doors closed. The box is about 5ft x 2ft x 17" and we have the light mounted at the top of the box with two regular size pc fans directly behind it for exhaust and 4 intake holes in the bottom of the box.

we have tried even putting a 9inch fan on high in there but thats still not enough so for right now we are leaving the doors open but im lookin for help asap!

I was trying to look in old forums for answers but i have to go to work so thought i could get some fast help and advice. thanks!

 

[Mr.Nugg]

still need some adviiiiiice

 

[beatster]

need some better intake and exhaust fans to move air while door is shut

 

[messn'n'gommin']

From this side of my screen it reads like there isn't enough air flow through the cab. A little more info would help. Do you have any pic's or diagrams of your setup? Are you using any kind of air filtration? How big are the intake and exhaust ports? For the PC fans, are they stacked? Side by side? Or are they just blowing on the bulb for cooling? The 9" fan you mentioned, is that an axial fan? Any additional info about the cab itself will help to pin-point the problem.

Namaste

 

[ColBatGuano]

It doesn't sound like there is any exhaust, at least not by your description. Air intake isn't enough, you need to have an exhaust at the top. I've never known any cab to be without one. My 4' x 4' x 6' cab only has a 4" exhaust--but along with a 170cfm can fan, and two 2" intakes at the bottom, it keeps the box at 76F with nice negative pressure--and I don't even use an air-cooled reflector.

 

[TheMonarch]

Is the IR from the light heating up the thermometer?

 

[Mr.Nugg]

 

[vprising909]

Ice cubes in large quantities.

 

[Hydro-Soil]

Is the IR from the light heating up the thermometer?

This is a good suggestion. Hold your hand about 10 inches away from the bulb... after about 30 seconds, is it uncomfortable to hold your hand there?

If it isn't... your temps are probably fine. Try shading the temp gauge with a piece of cardboard or something so the light doesn't shine directly on it and heat it up. Once you do that, the temp gauge should read the air temp properly.

Stay Safe!

 

[tokinafaty420]

I am trying to picture that box of yours. In my head it looks rather oddly shaped.
5' Length x 2' Width x 17" Height. You should turn it up on it's side and use the width has the height.

Your 150 HPS has to be taking up most of the head room in there....

 

[whythefnot]

I'm almost positive he meant 5 ft high

 

[Mr.Nugg]

lol definitely 5 ft tall but yea here are some pics. were gonna double up the pc fans on top of each other making it 4 fans all together. It is in hibernation right now so i will try and put the thermometer under some shade in the morning to test that theory. I have been reading a little on co2 systems as well, what do you all think about those as far as cooling and also for quality of bud?

 

[tokinafaty420]

lol okay, had me a laughing a bit. I couldn't imagine growing with only 17" of head room.

Co2 won't cool your cab, but it will allow the plants to deal with the heat better.

There is also the option of using a product like Silica blast by botanicare which helps plants deal with stress from heat .

The only thing I found that absolutely helped lower the temps was by forcing cooler air into the cab or removing the hot air faster and away from the air outside of the cab. Otherwise it'll just suck right back in and before you know it all the air equalizes inside and outside of the cab. If stealth is not an issue I'd recommend getting either 180 CFM or 265 CFM dayton blower and venting the warm air into a crawl space, attic, or if you use a scrubber too, outside.

 

[Abraham Lincoln]

You need to cut holes in the baseboard so you have a good intake flow

 

[Wasabi420]

yea your air intakes should be toward the bottom of the cab... also you should probably use a stronger fan at the top. your also gonna want an oscillating fan blowing on the plants to keep the air flow going and to keep the stems sturdy. good luck

 

[greenhead]

Those 2 PC fans ontop of your light - - Are they just sitting on top of the light, or are they actually exhausts blowing air out of the cab?

If they're just sitting on the top, then you need an exhaust blowing hot air out of your cab. It also has to be a fan that is capable of moving some CFM's. If those computer fans you're using are weak, then they won't do shit. Computer fans that have a decent CFM rating do exist.

 

[Weird Jimmy]

that light should have been built in to a separate enclosure area at the top of the box with intake/outtake fans on either side. I made the same mistake with the first cabinet I built. I had a 175w halide though. I tried more fans but they would barely put a dent in the heat. I finally decided to trade in that light and replace it with 24" T5 fluorescent fixtures and they work great. The T5's are great because you can buy single fixtures and mount them where ever you want. I mounted them across the top and vertically on the walls of the cabinet. I don't use my cabinet for flowering, but the T5's would probably give you similar flower results to the 150w you have now.

 

[Weird Jimmy]

here's a pic of the cabinet I was referring to. You can see the T5's on the walls and there are another 4 that are above the plants. Since the lights are mounted and stationary, I put shelving tracks on the walls and I raise and lower the plants on a shelf.

It has it's disadvantages, but they pale in comparison to having 100 degree temps.

 

[Mr.Nugg]

Thanks for all the inputs. As far as intake goes we do already have 4 1.5" wholes in the bottom and our exhaust IS mounted to the wall so i believe our problem could be not enough power pulling out so im doubling them up now. We just put our white widdow in a 1 gallon DWC this morning so im trying to make sure all conditions are perfect. Thanks again

 

[gdbud]

How is the air getting past that first shelf? and don't tell me the 1/2" gap between the door and shelf.
What size is your exhaust opening?
And a 1 gallon DWC is going to be to small!
My reservoir holds 9 gallons of water and I have two WW in there are consuming 1 gallon of water a day!