Tent Cooling

[alucard1uk]

So I have an issue as I need to cool the area but cant vent outside. I'm using 2x600w HPS lights with 2x 20l buckets, in a space of 3mx2mx2m (LxBxH) with a extract fan 6inch extract 720CFM with 2 addition fans inside the tent. I'm using DWC and to help cool the water I have put some (20kg) solid Iron weigh plates under the buckets to help absorb a bit of the heat . My issue is the room is siting about 27-28c during operating times. Looking to get the temp down about 7-8c.

I do have a window open and the room door is normally open during the day so there is some air flow.
I was thinking of spending 200-300 on a a/c but the issue is venting it.

 

[EARTHWALKER]

28c is absolutely fine. I like to run mine to 29-30 which is call the sweet spot.

 

[masonman]

Yup... nothing wrong with 28C.

Are you concerned with the air temps, or your DWC water temps? I would control the temperature of each independently.

If it's the DWC temps you're concerned with, could you freeze a couple 2L bottles of water, set one in the reservoir, leave one in the freezer, and just rotate them as needed?

Perhaps you need to shield the buckets from the lights? Try wrapping them with Mylar or Panda Film.

 

[Croatsan]

I'm using DWC and to help cool the water I have put some (20kg) solid Iron weigh plates under the buckets to help absorb a bit of the heat.

I'm not sure how that's gonna work. Metal will absorb the ambient temperature and it's gonna be, at least, a couple of degrees warmer than your reservoir content. You might end up, actually, warming up your res.

In order for metal plates to cool down the reservoir, res temps have to be higher than the ambient temperature, which is not the case. It's, usually, the other way around.

 

[TheFertilizer]

Your metal plates won't act as a heat sink unless there's a enough conductivity between the water and them. All your really doing is creating a large mass that is actually retaining more heat. If you fill your grow area with something non-conductive and not very dense, say boxes full of paper or something, then you will decrease the volume of air in your tent and that might help move more air faster which might in turn dissipate heat more.

Where are you venting your exhaust? If it's being recycled into your home, even if into another room, you are going to need an A/C to cool the air otherwise it will just build up. Most homes are too well insulated, they won't lost heat faster than that light setup will produce it. Just a simple window unit will work well. Otherwise you need to vent your exhaust directly outside of your home, utilizing a crawl space or preexisting ducting.

Wrapping wet towels (WET, not damp) around your DWC buckets will bring down the temperature of the water, but probably not by much unless you put direct air flow over the towels and maintain their moisture level. It will evaporate the water out of the towels though so that will raise humidity. The evaporative effect will cool basically cool down the towel and hopefully if the insulating properties of the plastic bucket aren't too great, the water inside too.

Try to make sure you're not trying to push air out of too great a distance of ducting. Insulated ducting might help a little bit if so, but booster fans along the line will help to keep air moving so that it doesn't just radiate through the air stream back into your tent. At a certain distance the ability to dissipate heat out of the tent will be overcome by the radiant effect on the air stream, so you want to make sure that the duct work between your tent's exhaust and to the outside is as short as possible.

Hope that helps!