Heat control issue / help

Oldenred1

Active Member
Have a 3x3x6 tent. Using a 315 cmh. Did a test run today and temps jumped to 91 in the tent on top of where the 5 gallon bucket is. That is with my exhaust fan on full blast and a fan blowing in the tent. I am keeping the house at 68. Using a ac unit that goes to an outside vent is not possible. What options do I have? I do have an ac vent going into the closet but it won’t always be running so sending a line to the tent probably wouldn’t be very effective would it? Thanks in advance.
 

BluntMoniker

Well-Known Member
Where does your exhaust pull from? Is it venting directly off the light, or is it just in the tent?

What direction is the fan blowing?

You may need to change your exhaust configuration, and have a fan or 2 pointed directly at the light to help drop temps.

As long as you can maintain temps below 85, you should be OK
 

spek9

Well-Known Member
Have a 3x3x6 tent. Using a 315 cmh. Did a test run today and temps jumped to 91 in the tent on top of where the 5 gallon bucket is. That is with my exhaust fan on full blast and a fan blowing in the tent. I am keeping the house at 68. Using a ac unit that goes to an outside vent is not possible. What options do I have? I do have an ac vent going into the closet but it won’t always be running so sending a line to the tent probably wouldn’t be very effective would it? Thanks in advance.
Where are you venting to? The same room the tent is in?

If so, there's one problem. You're likely going to need to exhaust to another room, or better yet outside (by the sounds of it that's not possible).
 

Oldenred1

Active Member
Where does your exhaust pull from? Is it venting directly off the light, or is it just in the tent?

What direction is the fan blowing?

You may need to change your exhaust configuration, and have a fan or 2 pointed directly at the light to help drop temps.

As long as you can maintain temps below 85, you should be OK
have the exhaust next to the light. Have one fan blowing into the tent. Will get a couple more for inside. System is dwc, won’t that be too hot for the water?
 

spek9

Well-Known Member
have the exhaust next to the light. Have one fan blowing into the tent. Will get a couple more for inside. System is dwc, won’t that be too hot for the water?
Blowing hot air around inside of the tent will not cool the tent down.

You need to exhaust the hot air from the tent somewhere other than in the same room the tent is in. No amount of blowing air in will alleviate the excess heat in the room.
 

Oldenred1

Active Member
Where are you venting to? The same room the tent is in?

If so, there's one problem. You're likely going to need to exhaust to another room, or better yet outside (by the sounds of it that's not possible).
it is to the same room. Likely not possible. Could vent to attic but really a last resort if I have too.
 

BluntMoniker

Well-Known Member
Blowing hot air around inside of the tent will not cool the tent down.

You need to exhaust the hot air from the tent somewhere other than in the same room the tent is in. No amount of blowing air in will alleviate the excess heat in the room.
Yes and no...

The movement of air from a fan wont remove the heat from the room... but heat transfer happens faster in direct airflow than it does in stagnant air. Especially on something that transpires like a human or a plant (which is why fans feel cool on a hot day even thought its blowing hot air), but similarly so on heat sources like lights.

Airflow in and of itself wont cool the environment.. but directed airflow with smart exhausting can noticeably lower temps. It's the same idea as sucking the air directly off your HPS to exhaust. Your removing heat via heat transfer across moving air.

2x3 tent that exhausts into the 4x8 closet its in got up to 95°f under an HLG 260w diablo with nothing but the exhaust fan running. 1 fan blowing at the driver and 1 fan pointed at the boards had temps 77-83°f dependent upon how long the light had been on.

Not to be argumentative, but I think the blanket statement that moving air wont cool a room isnt entirely true. If I turned my exhaust off and had just 2 fans.... I'd be lucky to see 94°f, sure.. but air movement in conjunction with exhaust surely has cooling capability to an extent beyond simple exhaust.. dependent upon heat source, room size, airflow, and the multitude of other things that effect the environment of a closed space
 

Apalchen

Well-Known Member
I ran 2 3x3 tents in a bed room that was roughly 10x12 and had a cmh in each one I also had a 2x4 in there with a 4 bulb t5 in it. I know everyone says don't vent into the same room but I did in this instance. Yes if heat is an issue venting out of the house is better but in this spot I couldn't. I did keep the door to the room cracked open at least a foot.

What size fan are you using? I had my tents sitting with about a 2 foot gap in between them there was a 6x24 carbon filter sitting directly on the floor a 6 inch fan sitting on top. Directly after the fan I had a 6 inch y. On the end of each leg of the y I had a 6 to 4 Inch reducer. 4 inch duct from there to a hole on the side of each 3x3. My temps were never over 85 and rarely over 82.

My central air in the hottest part of summer did have to be set to 65 if I was trying to veg during the day. As long as I was flowering at night my temps were good set to 68.

Make sure to use a vent on the bottom of the tent on the opposite side of the hole your exhaust is going out of. I used a 6 Inch piece of metal flex duct a foot or so long with panty hose on the end to catch dust.
 

Oldenred1

Active Member
Added 3 fans inside the tent. Down to 85 inside but dropped humidity down to 31%. Really didn’t want to do it it but gonna add an outside air vent for the exhaust tomorrow. It did raise the closet temp 6 degrees. Probably gonna add an external reservoir around 20 gallons to control the water temp. Hoping to not have to add a chiller. Feel free to chime in with tips on this. Thanks
 
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