Peltier Light Cooling

[alienfarts687]

I've seen a few cheap Peltier coolers around the internet and it's got me wondering if it might be worthwhile for active LED cooling on a small scale? I know they're not terribly efficient, but it seems they work fairly well for computers, so perhaps they would work for small grow areas? Any thoughts? I might get one anyway just to play around with, not necessarily for my lights, though, but I'm curious if this is actually feasible.

[LivingLight]

I've seen a few cheap Peltier coolers around the internet and it's got me wondering if it might be worthwhile for active LED cooling on a small scale? I know they're not terribly efficient, but it seems they work fairly well for computers, so perhaps they would work for small grow areas? Any thoughts? I might get one anyway just to play around with, not necessarily for my lights, though, but I'm curious if this is actually feasible.

of course it is working. But the idea to use 70w to gain some 10°C on a 100w led, that's not viable
i actually got a 75w peltier module i'm trying to build a camping cooler xD, the little boy can draw max 60w of heat according to the datasheets.

[Professor Xavier]

Water cooling may make more sense from a system perspective if you're able to put your radiator outside of the system. Uncle_Psycho was talking to me aboot a lady that cooled her lights and used the heat energy for her water heater input. When I was looking at HPS lighting, I was considering using a wood stove fan to get some cooling and air movement.
Chilled has a water cooling option for their lights which intrigues me.
Really though, as I educated myself on lighting, I realized that I wanted to be able to run led's softly from as many points of light as possible to get the best uniformity at a minimum PPFD. The efficient mid-power LEDs waste far less heat and are never really driven that hard in my new builds, so cooling becomes less of an issue.
I would think for the time and money and complexity/risk of a DIY water cooling system, you'd be better off buying an extra strip light or two to even out your canopy coverage and reduce light cold spots than to be able to run fewer boards hotter and have to raise your hanging heights.

[alienfarts687]

Actually, it seems like some computer water cooling systems use a Peltier to cool the water. Perhaps it makes more sense because water holds heat better, so the lower efficiency of the Peltier isn't as significant?

Anyway, I agree, Professor Xavier. It's probably cheaper and more efficient in the long run to run more strips softly. Regardless, it seems like a fan or two would make more sense than anything if cooling is necessary. Water cooling could be disastrous if there's a leak, and I'd rather avoid that.

[LivingLight]

Actually, it seems like some computer water cooling systems use a Peltier to cool the water. Perhaps it makes more sense because water holds heat better, so the lower efficiency of the Peltier isn't as significant?

For a computer, the chips are not constantly running at full charge and the benefits are decent regarding to the power consumption. Also, gamers don't really care of 100w less or more if their chips can run perfectly cooled.
But for a led, running at 40°C or around 10°C doesn't make a huge difference. Still significant but not enough to spend so much power in it imo. Why not just use a low profile cpu/gpu fansink, or a classical water cooling as it was alrdy mentioned ?
You still can have fun trying to run a led under 0°C or anything you wanna try but that's not really relevant xD

[alienfarts687]

For a computer, the chips are not constantly running at full charge and the benefits are decent regarding to the power consumption. Also, gamers don't really care of 100w less or more if their chips can run perfectly cooled.
But for a led, running at 40°C or around 10°C doesn't make a huge difference. Still significant but not enough to spend so much power in it imo. Why not just use a low profile cpu/gpu fansink, or a classical water cooling as it was alrdy mentioned ?
You still can have fun trying to run a led under 0°C or anything you wanna try but that's not really relevant xD

That makes complete sense. I figured this wasn't really a practical application for Peltier cooling. My light temps are around 40-50°C while dimmed pretty low. I already have 5 12vdc fans on order. One or two should help if temps get too high.

[unkle_psycho]

With me before I attached heatsinks just putting an ocillating fan on the smallest power, perhaps a meter away from the plants made a huge difference in strip temperature.

But I'm really strugling with growroom temperatures even though its pretty warm outside.
I decided to modify abandoned furniture using elements we normally isolate houses with, to stop loosing any of that valuable heat. And since I'll be looking at sealed rooms from now on, I will start researching about co2. Leds are forcing me to this approach. HIDs forced me to ventilate a lot

[alienfarts687]

With me before I attached heatsinks just putting an ocillating fan on the smallest power, perhaps a meter away from the plants made a huge difference in strip temperature.

But I'm really strugling with growroom temperatures even though its pretty warm outside.
I decided to modify abandoned furniture using elements we normally isolate houses with, to stop loosing any of that valuable heat. And since I'll be looking at sealed rooms from now on, I will start researching about co2. Leds are forcing me to this approach. HIDs forced me to ventilate a lot

I already have a heatsink technically - thick aluminium sheet. But nothing fancy with fins. I think a small fan will make a big difference. On the other hand, I'm thinking a Peltier might be more effective for dehumidification. One day when I have too much time on my hands, I might make a dehumidifier.

[unkle_psycho]

I usually don't need to worry about dehumidification, only in the autumn. Never saw a plant mold inside in over 15y of growing. Last year I put some boxes with some chemical that attracted moisture. It pulled a few litres from the room, but I didn't have a meter to really follow moisture levels. Next Autumn I will get a bunch of them and measure. I guess you are somewhere way more humid ;D

I put a heatsink thats a little over 50mm wide, and has a little fin. It dropped the temperature from about 50c to around 35c. Using a weak desktop fan on low power had about the same effect.

[alienfarts687]

I was getting around 75-80% at times. The room my tent is in gets quite humid. I've since put a small, reusable dessicant dehumidifier in the tent, which seems to keep it down in the 50-65% range. That's still a bit high for my liking for flowering, even if it's fine for veg.

The humidity in my greenhouse, on the other hand, is ridiculous. I've already started to see signs of mould in my growing medium, and even on a few leaves.