Temperature problem with CXB Cobs

[BM9AGS]

I'd go to half power on each! Better efficiency

 

[OGHulk]

Even if you get Temps under control, I predict you are going to cook those plants under that kind of light. Just too damn much. Yes you can have too much of a good thing.

actually i thought this setup was "stronger" than a HPS 400w but only by a little i never thought that it would pull that much light

Ohh spray paint the tops of those buckets white. Sides too if you can manage. Or I've seen a guy buy cheap car sunshades at the dollar store and cut them to go over the buckets. That'll be too hot for your growing method unless you're running a chiller

actually i not going to grow in DWC anymore, i'm just waiting for my smart pot and coco

I'd go to half power on each! Better efficiency

ok thanks bro

 

[BM9AGS]

actually i thought this setup was "stronger" than a HPS 400w but only by a little i never thought that it would pull that much light

Yes stronger.....than even a 600w hps

 

[Bubblin]

Is that top clip fan blowing hot air down onto the plants?

I would remove the driver from the tent. Then toss a fan on the floor blowing heat up towards the exhaust keeping the COB heat @ the top of the tent.

You could also try to use some type of material to separate the the tent into two sections, top section with the coolers on the COBs and the bottom section COB/plants. It wouldn't have to be a snug fit or anything, but just enough so most of the heat from the COB coolers stays in the top section and gets blown out the exhaust.

edit, effing typos, fak I need more coffee

 

[OGHulk]

Sounds like you need an AC then. A swamp cooler may do if you are in a dryer climate.

i will try a stronger fan and see, i'm starting to think the problem come from air stagnation

 

[coreywebster]

Have you got all your passive intake flaps open at the bottom of the tent?
Edit, looks like you have from the photo.

Where are you taking temps from?

 

[OGHulk]

Is that top clip fan blowing hot air down onto the plants?

I would remove the driver from the tent. Then toss a fan on the floor blowing heat up towards the exhaust keeping the COB heat @ the top of the tent.

You could also try to use some type of material to separate the the tent into two sections, top section with the coolers on the COBs and the bottom section COB/plants. It wouldn't have to be a snug fit or anything, but just enough so most of the heat from the COB coolers stays in the top section and gets blown out the exhaust.

edit, effing typos, fak I need more coffee

the clip fan is off, it is useless, i will replace it by a tower fan and see
i thought the leds wouldn't produce too much heat and that a clip fan would be enough but i was wrong

the little gray box you see is the exhaust fan controller, it doesn't produce any heat, the drivers are outside
that what i wanted to do actually, a transparent rigid pvc sheet below the cobs, i will try that if can't manage to decrease the temp with a stronger fan plus exhaust fan

Yes stronger.....than even a 600w hps

these cobs exceed my expectation then !

Have you got all your passive intake flaps open at the bottom of the tent?
Edit, looks like you have from the photo.

Where are you taking temps from?

from the plant level
at the top, where you see the exhaust duct, the temp is lower

 

[a senile fungus]

That's looks like a inline duct booster fan, as someone else pointed out. Those are for supplementing the airflow in a long run of duct, they can't create much static pressure because of the design.

If you replaced that with a real blower then you'd solve your problem. I'm guessing that tent doesn't have much airflow right now... Air is stagnating.

Well, that and address the fact that you have a shit ton of light in that tiny space


Good luck, hope that helps.

 

[Bubblin]

the clip fan is off, it is useless, i will replace it by a tower fan and see
i thought the leds wouldn't produce too much heat and that a clip fan would be enough but i was wrong

the little gray box you see is the exhaust fan controller, it doesn't produce any heat, the drivers are outside
that what i wanted to do actually, a transparent rigid pvc sheet below the cobs, i will try that if can't manage to decrease the temp with a stronger fan plus exhaust fan

these cobs exceed my expectation then !

Ahh ic

I have a few of those exact fans, if you pop off the front fan grill they blow a lot more air. I love emm on the low setting blowing across the very tops of the plants

 

[OGHulk]

That's looks like a inline duct booster fan, as someone else pointed out. Those are for supplementing the airflow in a long run of duct, they can't create much static pressure because of the design.

If you replaced that with a real blower then you'd solve your problem. I'm guessing that tent doesn't have much airflow right now... Air is stagnating.

Well, that and address the fact that you have a shit ton of light in that tiny space


Good luck, hope that helps.

it's not a duct fan, don't know how you call them in the US but it's an industrial exhaust fan

 

[a senile fungus]

it's not a duct fan, don't know how you call them in the US but it's an industrial exhaust fan

You should take it off the speed controller...

I just removed my speed controller from the equation. I had one of my blowers turned down for noise control but the hum of the motor was much louder on the controller. Turns out that sounds of the hum is louder than the whoosh of air at full speed...

Good luck I hope you figure it out


Also, why are your heatsink cold? That seems odd... Are they mounted properly and all that?

 

[OGHulk]

Ahh ic

I have a few of those exact fans, if you pop off the front fan grill they blow a lot more air. I love emm on the low setting blowing across the very tops of the plants

yes they are quite nice for that

You should take it off the speed controller...

I just removed my speed controller from the equation. I had one of my blowers turned down for noise control but the hum of the motor was much louder on the controller. Turns out that sounds of the hum is louder than the whoosh of air at full speed...

Good luck I hope you figure it out

it's not an electronic speed controller, the motor doesn't make a "hum" on it, it's barely audible at low
if i increase the speed of the fan the sound of the air will be audible and i want to avoid that

thanks bro

 

[Will Thayer]

Bad news is you have too many COBs in that tent. Good news is you have enough COBs for a second tent just like the one you have that you can double your return with. Also if you are venting outside the tent into the same room you're intaking air from you will have heat build up running all them photon engines in such a confined space. Where is the heat going to go? Unless your home is air conditioned you are exhausting warm air into a room and intaking the same air back into the tent.

Cheers,
Will

 

[coreywebster]

Try taking temps from above the light line, your are getting radiant temps if your directly under the light. Plants can handle higher radiant temps than air temps. You want to have the thermometer in the shade. That will make a difference and give a true reading.
All that said though, that's a hell of a lot of watts of any kind in a small space.

 

[captainmorgan]

You don't need 50 watts per sq/ft to hit 2 GPW,Ive done it with just under 30. I own both of these fans and they are very quiet.

http://www.solerpalau-usa.com/tdsilent.html

http://vortexpowerfans.com/s-line

 

[OGHulk]

Bad news is you have too many COBs in that tent. Good news is you have enough COBs for a second tent just like the one you have that you can double your return with. Also if you are venting outside the tent into the same room you're intaking air from you will have heat build up running all them photon engines in such a confined space. Where is the heat going to go? Unless your home is air conditioned you are exhausting warm air into a room and intaking the same air back into the tent.

Cheers,
Will

so how many cobs should i run for this tent (4x2x5,90) ?

i'm venting in the same room but the ambient temperature remain the same (75°F) because the house has good air circulation

Try taking temps from above the light line, your are getting radiant temps if your directly under the light. Plants can handle higher radiant temps than air temps. You want to have the thermometer in the shade. That will make a difference and give a true reading.
All that said though, that's a hell of a lot of watts of any kind in a small space.

good to know
right now it read 79 °F with 4 Cobs at 25w

as for the watts/space, where i live people use frequently 400w HPS in that kind of space

You don't need 50 watts per sq/ft to hit 2 GPW,Ive done it with just under 30. I own both of these fans and they are very quiet.

http://www.solerpalau-usa.com/tdsilent.html

http://vortexpowerfans.com/s-line

with the same cobs ?
what growing method do you use ?

 

[Resinhound]

so how many cobs should i run for this tent (4x2x5,90) ?

i'm venting in the same room but the ambient temperature remain the same (75°F) because the house has good air circulation


good to know
right now it read 79 °F with 4 Cobs at 25w

as for the watts/space, where i live people use frequently 400w HPS in that kind of space



with the same cobs ?
what growing method do you use ?

400watts of HPS is not the same thing as 400watts of high efficiency leds. Those cobs put out at least 20% more light for the same watts, so you could use alot less cobs for the same amount of par as an HPS... Thats kinda the point of high efficiency leds.

 

[JorgeGonzales]

actually i thought this setup was "stronger" than a HPS 400w but only by a little i never thought that it would pull that much light



actually i not going to grow in DWC anymore, i'm just waiting for my smart pot and coco



ok thanks bro

According to Supra's numbers, you are right at about a 600W equivalent. ~1100 umols, ~1500 PPFD. Pretty bright.

 

[captainmorgan]

with the same cobs ?
what growing method do you use ?

I have lights based on 3070's and 3590's driven between 800ma and 1400ma. and usually do around 30 watts sq/ft. I mainly scrog and have many documented grows here. You should be able to get 1.3 to 1.5 GPW with 30 watts sq/ft with about any style grow unless it's a low yielding strain.

 

[OGHulk]

thanks guys

i think i will setup a second grow tent after i finish this grow

the good news is that i fixed the temp issue by powering only 8 Cobs which according to you is enough and putting a stronger fan in the tent !
i will try powering all the 16 at half the power and see if the temp problem reappears