Trying to control heat

My last grow (pulled a week ago) had baaad foxtailing due to temps getting into the 90s.

I just switched my hps setup for cobs and now I've got 675w of cobs running. I have 3 fans down low, blowing up, the Heatsinks are cool to the from all the air blowing up. There is a 6 inch hurricane fan at the top of the tent, exhausting to a chimney.

I also went out and got a 10000btu portable ac. The ac has to sit across the room, because running enough exhaust ducting to reach the tent makes the room hotter.

So, running the ac non stop gets the room right outside the tent to 68f. But the temp inside the tent is 80f and getting hotter.
I can open the tent door and the temp drops to 74 after time, but I'm thinking about flower, I'll need to keep the tent shut so I can contain smell.

What do I need to do to get the temp to like 76f?

An idea I thought, is duct the cool ac air into the bottom of the tent, but the ac has a big wide rectangle it blows the cold air from, I have no idea how I'd get ducting around that.

What do you guys think?

Also, bonus question, my plants are vegging 16-8 right now, turning on at 4am and turning off at 8pm. I'd really like to flower during night though. When I switch to flower, can I just set the lights to turn on at 11pm and turn off at 11am?

Thanks

https://www.amazon.com/gp/product/B002XITVCK/ref=ox_sc_sfl_title_28?ie=UTF8&psc=1&smid=ATVPDKIKX0DER
but running an 11.9 amp portable A/C 24/7 is going to crush your electric bill.

a spilt A/C is the best scenario, with the dual hose A/C's odor control, you will need and extra can, but I'm sure there is about a dozen configurations that could be made here.

dim the lights(turn some off), set the A/C to 76 and use fans, just go dark till the weather is better.

don't mist them, not sure how your growing but keep the medium with just a bit of moisture, water is not going to cool your plans. heat brings bugs, mold, fungi just looking for some water to make trouble.

ganjafather27 said:

My last grow (pulled a week ago) had baaad foxtailing due to temps getting into the 90s.

I just switched my hps setup for cobs and now I've got 675w of cobs running. I have 3 fans down low, blowing up, the Heatsinks are cool to the from all the air blowing up. There is a 6 inch hurricane fan at the top of the tent, exhausting to a chimney.

I also went out and got a 10000btu portable ac. The ac has to sit across the room, because running enough exhaust ducting to reach the tent makes the room hotter.

So, running the ac non stop gets the room right outside the tent to 68f. But the temp inside the tent is 80f and getting hotter.
I can open the tent door and the temp drops to 74 after time, but I'm thinking about flower, I'll need to keep the tent shut so I can contain smell.

What do I need to do to get the temp to like 76f?

An idea I thought, is duct the cool ac air into the bottom of the tent, but the ac has a big wide rectangle it blows the cold air from, I have no idea how I'd get ducting around that.

What do you guys think?

Also, bonus question, my plants are vegging 16-8 right now, turning on at 4am and turning off at 8pm. I'd really like to flower during night though. When I switch to flower, can I just set the lights to turn on at 11pm and turn off at 11am?

Thanks

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Are you running an inline fan ? If so how many cfm? My tent temps stay pretty close to ambient room temps

714steadyeddie said:

Are you running an inline fan ? If so how many cfm? My tent temps stay pretty close to ambient room temps

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ganjafather27 said:

There is a 6 inch hurricane fan at the top of the tent, exhausting to a chimney.

Click to expand...

435cfm

are you exhausting outside the room? I'm growing with a 600w hid 18/6 in a tin shed in the deep south during a heat wave with a 4" 190 cfm centrifugal fan and temps are good enough that my lady is growing like a weed, so well that i haven't even checked the temp. If you are exhausting outside the room do you have a ventilated hood?

dirtWeevil said:

are you exhausting outside the room? I'm growing with a 600w hid 18/6 in a tin shed in the deep south during a heat wave with a 4" 190 cfm centrifugal fan and temps are good enough that my lady is growing like a weed, so well that i haven't even checked the temp. If you are exhausting outside the room do you have a ventilated hood?
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Yes I've said twice now I'm exhausting to a chimney. Chimneys go outside.

And the plants grow fine, but when your temps are over 80,the bud starts foxtailing which make it loose and shitty. Don't want loose shitty weed.

And no, cobs are chip on board leds. You cant put that in a hood.

You need an 8" blower.....or Yes put the COBs in a hood. Have the blower directly exhaust the heat from the sinks before it has time to heat the surrounding air.

If the driver is inside the grow space. It's a high heat producing item. My driver runs an average of 108°f with the sinks running around 93°f. When the driver was inside the grow space it heated the hell out of it. Like a little radiator heater. 5°f spread of temps.

With a 8" blower on a 2x4 tent. Four 48v COBs running at 50%. The inside of the tent runs 3°-5° hotter then outside room temperature. Currently the outside room is 72.8°. Inside the tent it's a solid 74°.

ganjafather27 said:

Yes I've said twice now I'm exhausting to a chimney. Chimneys go outside.

And the plants grow fine, but when your temps are over 80,the bud starts foxtailing which make it loose and shitty. Don't want loose shitty weed.

And no, cobs are chip on board leds. You cant put that in a hood.

Click to expand...

calm down homes, you're the one with the heat problem and in your words loose shitty weed not me, if the plants grow fine then what the fuck are you on here asking for advice for? Maybe your strain grows fox tails on its own like anything that has chem in the lineage is apt to do, or any number of other strains.

it never ceases to amaze me how mothafuckers will post asking for advice and then turn into a goddam weed genius the second someone tries to assist insisting it can't be this or that. I know what a fucking chimney is asshole, sometimes fuckin chimneys get clogged, the main reason for "i can't get my heat under control" is poor ventilation, find whats poorly ventilated and then your heat might be more manageable