Cooling Issues, Think need redesign ?

Hi ALL,

I seem to be having problems with heat and trying to cool the tent down. I've listed the specs below for reference, but i can't see why i have heat issues ?

** Spec **

Tent - 160cm(L)x80cm(D)x160cm(H)
Fans - 2 x 6" 1000m³/h Box Fans (Intake - From almost outside cold feed in (CF attached) to FAN, then to Y-Piece to air feed to tent, and start of Lights / Exhaust - From End of Lights to Y-Piece, which also gets a feed from the CF in the tent)
LIGHTS: 2 x 600w (HPS) Digital Ballasts with Aerowing Air Cooled Reflectors on 12/12 - Lights are linked together via 6" ducting.
CONTROL: SMS 14amp Twin Controller. Idle @ 60%/Max Temp @ 24c set to AUTO

So that's the setup as it stands, I did a test with the temp gauges i have, with temps outside being at 2c, at the entrance of the INTAKE fan i placed a temp probe that measured at 11.8c, as i mentioned the CF is almost outside, then i put a temp probe at the exit of the cold feed in the tent (Lights OFF), and it was at 16.7c(don't ask were 5c came from, but god knows), and when the lights were ON and have been at 100% (600W) each for a few hours the temps at mid bush height was 27c !!!!

So as you can see i have heat gremlins, and can't find or catch the little sh*ts !

If anyone has a solution or an idea that would be great, as it's getting on my nerves, or even a redesign if needed.

Thanks

ok i used to have serious temp issues, but i sorted them out with a portable ac unit, my set up is as follows 5" outlet for ac unit with a 4" duct into the tent which is a dr90, cold air intake is facing the floor at the centre of the tent i also have a 4" carbon filter to inline 4" tt100 which is also inline with a 4" ventaxia inline fan to keep the negative pressure in the tent to keep the glorious scent in check. my lighting is only 430w hps with a euro reflector but having said that my ac is set to minnimum. my ac,lighting and one of my fans are on a 12/12 timer the other fan keeps the negative pressure at all times to draw the scent through the filter, lights out temp 63F lights on temp72% RH sits between 38% and 58%.

Send more Air in via Intake, also remember if this in inside a house temps are going to be on average 10degrees-ish above the Room Temp

DARKDONZ said:

ok i used to have serious temp issues, but i sorted them out with a portable ac unit, my set up is as follows 5" outlet for ac unit with a 4" duct into the tent which is a dr90, cold air intake is facing the floor at the centre of the tent i also have a 4" carbon filter to inline 4" tt100 which is also inline with a 4" ventaxia inline fan to keep the negative pressure in the tent to keep the glorious scent in check. my lighting is only 430w hps with a euro reflector but having said that my ac is set to minnimum. my ac,lighting and one of my fans are on a 12/12 timer the other fan keeps the negative pressure at all times to draw the scent through the filter, lights out temp 63F lights on temp72% RH sits between 38% and 58%.

Click to expand...

Send me a link to that portable AC unit, i have had my eyes on a few but they are made very cheap and not for the purpose i want it for!

Thanks guys for the information. I was thinking of maybe dedicating the INTAKE box fan for just the cold air feed into the tent instead of y-piecing it off and feeding half through the lights and the other half into the tent. But i had a similar setup to that only 2 months ago, and changed it to this one due to temps being an issue then.

Or I can get just a normal 6" TT/RVK inline fan as the dedicated cold feed into the tent ?

You ae usig way too much light. That is what? 12 square feet of flooring? you have 180,000 lumens??? Why???

That is waaaaaaaay too much illumination.

First of all, use just one 600w - that is plenty for that space

Bud Grauer - Hi, But wouldn't it mean that i will get a big reduction in yield ?, as im reducing the amount of light by 50% ?. My ballast is dimmable, so i could run each bulb at either 300w(50%),450w(75%),600w(100%),660w(boost). I've only ever ran them before at either 75% or 100%. Would you recommend turning then down to 50%/75% instead of the 100% i'm running them at ?

That is a really good idea to use two lamps - to spread the light out more evenly - and dim them by half.

I understand what you are asking. Growing excellent quality requires ballancing limited space vs amount of light. You cannot just pile on more light and reasonably expect a proportional increase in yeild.

Marijuana that is bred from Afghan indica has much more chlorophyll that equatorial sativa - that's why it is such a dark green color. Almost all breeder grown seeds have a large amount of indica genetics. They do this so that it flourishes indoors under artificial light, and to prevent plants that are ten feet tall and too hard to manage (and b/c indica flowers faster).

Indica hybrids do not need such intense light - it will flower just fine under 6000 lumens per square foot. If you enhance with co2, then you can increase your yeild of buds b/c the plant grows faster and can utilize the extra light (you have to increase the temperature too).

By using HID lights equivalent to the equatorial sun for 12 straight hours, you would increase the rate of growth some, but not the yield of buds (unless you add co2 and control the temperature very carefully - this is the balancing act that expert growers have mastered).

But using so much light in such a small space creates a serious risk of something going wrong ... if things go really wrong, you risk losing a whole crop. Trying to crowd so much groth into such a small area is flirting with disaster.

And even if so much light would cause a thick canopy, what about the root systems??? You would have to have extra huge - deep - pots to accomodate the massisve root systems required to sustain a super thick canopy. You do not have the vertical room in your tent for the plants you are likely to grow under all that light.

You have a great set-up. Do it right and you are going to get a years worth of excellent quality buds.

Get another tent if you want to safely increase yield.

Bud Grauer: Thanks for the info, very much appreciated. I am aware that maybe there is too much light due to heat output, and i have turned them down to 75% (440w) the majority of the time. But i have noticed a big difference when it has been able to be on 100% (600w) for each bulb for a few weeks. Mine is all personal so only eight plants under the setup. I think the key for me is to try and gain access to a better source of outside cool air.

I've been reading about and think i might have stumbled onto my possible problem. I have quiet a bit of ducting, all the ducting leading to the fans is fairly short <2m, except the exhaust from the lights that is about 3m. But after the fans the exhaust is ducted with about 10m, remember that their is a few bends in all the ducting, which i know will affect the efficiency of the fans, but i'm woundering if the long exhaust duct is causing a negative effect on the air pressure ?

Just an update. I disconnected the long exhaust ducting from the fan leading out. And this have dropped my temps by 4.6c, pretty amazed, makes sense NOW , but just never thought of the simple things, just thought it had to be an overly complex solution to a fairly straight forward problem. Air Pressure, looks like it can causing big temp issues if their is too much length on the ducting runs, and also another big influencer is bends especially 90° bends.

I'm hoping to try and get the temps down even further as it seems to still have to make the fans work at about 80% when lights are on and it's holding it at my set temp of 23-24c.

If anyone has any other ideas please share

XMS²;7131963 said:

Just an update. I disconnected the long exhaust ducting from the fan leading out. And this have dropped my temps by 4.6c, pretty amazed, makes sense NOW , but just never thought of the simple things, just thought it had to be an overly complex solution to a fairly straight forward problem. Air Pressure, looks like it can causing big temp issues if their is too much length on the ducting runs, and also another big influencer is bends especially 90° bends.

I'm hoping to try and get the temps down even further as it seems to still have to make the fans work at about 80% when lights are on and it's holding it at my set temp of 23-24c.

If anyone has any other ideas please share

Click to expand...

I found this out recently also, i removed a couple feet that were between my DIY carbon filter and the cooltube, helped tremendously on temps and now it's a 600 on switch able in a 2x2 space