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Wine Chiller Terrarium - I'm Trying It! - Thermoelectric Cooling Fun!

During the last Black Friday madness I was able to pick up one of the smaller chillers for under $50. I did a ton of research before pulling the trigger on this as I was not able to find a single example of one that worked. After much reading and talking to a few people I believe this may work for what I'm trying to do with it.

A few disclaimers.....This is VERY untested and the lack of information about practical usage of thermoelectric cooling is amazing. Almost all the information I was able to find about them said this would not work, it took a lot of digging to find the positive examples. I have no intention of growing anything large, my main goal is Dendrobium cuthbertsonii. Anything else is just gravy.

I would not recommend anyone try this unless they enjoy using items in ways they are not intended and would have a use for the wine chiller if things go horribly wrong. Make sure you read up on thermoelectric cooling a bit also, knowing why it works will help you make it work properly.

With that out of the way. I picked up a Candor CW-25FDI .88cuft 60W chiller (outer dimensions 10 1/4" W X 19 7/8" H X 18 1/2" D, from package I did not measure)(inner dimensions approx. 7" W X 13" H X 12" D)

For lighting I will be using a single http://www.rapidled.com/4-led-solderless-moonlight-kit/ with 2 cool white and 2 warm white LEDs. Some short term testing of this kit is here http://www.terraforums.com/forums/s...le-Short-Term-LED-Experiment-with-a-few-Cephs The heatsink is a scratch and dent version of http://www.rapidled.com/6-x-10-black-anodized-aluminum-heat-sink/ so it was $10.

If anyone is wondering about how to wire these things up check out http://www.terraforums.com/forums/s...uild-a-Cephalotus-grow-space-would-love-input! starting on page 3. Same concept but without the dimmer and much easier. After I got everything all wired up with 40 degree lenses I placed the heatsink inside and turned everything on. The starting temperatures were 74 inside the chiller and 72 outside at 6:45pm. Right around 1 hour later the chiller temp gauge read 55 degrees but the external/internal one was reading 58 inside and 72 outside. So the chiller was able to cool the LEDs 16 degrees in about an hour with the LEDs running. Now keep in mind these moonlight kits are no where near full power LEDs and they don't generate that much heat.

DSC_0847 by randallsimpson, on Flickr

If the temps hold and everything looks like it should work out I will be getting some really thin glass and building a custom terrarium to slide inside the chiller to maintain the humidity while keeping the chiller fan and electronics in "normal" humidity levels. Add a fan and that's it!

Any suggestions are very welcome.
Dendrobium cuthbertsonii is a beautiful plant, and one I'd love to grow if I could. Do you think your LED set up puts out enough light for it? Do you know what the lux count is at the distance you will be growing your plants?

Good luck! Tell us how it goes.
I believe there is enough light to grow a Ceph with good coloration so that leads me to believe there would be enough for the cuthbertsonii, but there is really only one way to know. I do have some concern that I may need 80 degree lenses or a few more LEDs as the spread of light is more spotlight than I would like. I'm still feeling out the cooling potential of this thing so I'm going to leave it at these 4 for a while.

I've tried meters in the past and never found the results to be of any use and they seemed to be all over the place from one meter to another so I completely stopped using them years ago as the results were never useful. Quote from another thread as to why meters are not that useful once you get to messing around with lighting spectrums.

When you start digging into the technical #'s for the LEDs you get a lot of useless information like Luminous flux, why is this useless? Its a measurement of visible light so if you look at the RED LEDs its .720 while the warm white LED with the same power is 93.9....130X brighter to the human eye, but which LED is actually producing more light, visible to the human eye or not? I was not able to find that information but as I've said before I only understand about 1/3 of what I'm reading with this stuff.

I went to Lowes this morning and got $10 worth of cut glass and spent about an hour sanding all the edges. Now I just need to assemble it.
Following some really nice instructions http://www.dendroboard.com/forum/pa...tructing-euopean-type-vivarium-step-step.html I had my local Lowes cut 3/32" glass to what I hoped was the proper dimensions. After about an hour grind/sanding the edges down we assembled everything but the front door. I have yet to figure out how I want to attached it so until I'm sure this is a winning idea I'm just going to use some plastic wrap or something for the door. Once I'm sure this concept will function properly I'll figure out the door. I still have another round of drying and applying more silicone to go but here it is so far along with a Utric. calycifida leading a hand. Oh and yes its upside down at the moment.

DSC_0848 by randallsimpson, on Flickr

I had a bit of an accident with a Heli yesterday that made me repot/divide it before I was ready:-( But that provided me with a volunteer to enter the chamber! It is just an H. minor and where it broke off there was no roots on this piece so it will be an uphill battle. The chiller temp gauge has read steadly 54-56 degrees every time I've passed it, the other temp gauge has read 55-58 during this same time frame. The humidity gauge in with the Heli has read 80-85% constantly. So far everything seems to be working well.

DSC_0849 by randallsimpson, on Flickr
Finished up the glass terrarium this morning and wired up the fan. Everything is working perfectly so I'm just waiting for something to go horribly wrong now :-D

Temps are stable all day/night, humidity is constant 80-85%. Moved in a U. humboldtii and repotted a piece of U. quelchii to put in there. I'm not willing to risk larger plants yet. Now its just a waiting game.

DSC_0862 by randallsimpson, on Flickr
Randall, very nice! I had a mini-fridge set up very similar to this a few years ago. It worked well for me. I just got tired of moving it back and forth to school. If you have a facebook account, check out the Planted Glass Boxes page. Justin built a wine chiller tank a year ago, and it has done very well for him and its current owner.

How are you generating a temp. drop at night?
I just don't get Facebook, the format is useless for almost everything. I looked around a little but the format is just way to odd for any useful information transfer.

The only fridge I could find on that page was a compressor fridge, those have been a known working item for a long time now. This setup is using one of the Thermoelectic cooler (Peltier cooler) instead of the compressor and thus the untested undocumented part. You can find many examples using compressor based coolers for terrariums out there.

At current I am not generating a temp drop at night, I'm more interested in this things ability to maintain the lower temperatures long term with all the conflicting information about Thermoelectic coolers out there I'm still not convinced this thing will work long term. I've never been completely convinced about the "need" for a drop at night, from reading up on other plants that grow in the same area and the way people are growing them successfully I believe a lower temp throughout the day is what they really need and not a massive drop at night. The target temp seems to be 60 for the orchid crowd so I figure that is where I will start.

Since my focus is more toward a few select orchids and Utric's I'm not overly converned about the temp drops. The plants I put in there are more for testing and what I was willing to lose if things go horribly wrong and if this setup looks like it will work I'll be replacing almost all of them with others.

As far as the setup, everything is still working great. The only issue is the internal temp gauge and the external gauge never agree as to what temperature the box is at :-D. Right now they read 2 degrees apart.
I added a penguin to the chiller this evening!

DSC_1014 by randallsimpson, on Flickr

Figured I'd snap a photo while I had the box outside of the box, and you could actually see what is in there. I added the mylar backed foam to try and maximize the light I'm getting off the LEDs.

I have been getting some condensation buildup in the bottom of the chiller that is leaking out onto the table. I'm hoping this is from my plastic wrap door so I went and spent the $2 for a proper glass door. Only time will tell if that was the problem or not, I have a few other culprits to look into if the door turns out to be innocent.

As for the temps they are staying right where I have it set within 1-2 degrees.

So far there are 2 Sarr seed pots (will only be in there for a month or so), U. humboltii, a tiny U. quelchii piece, H. minor, H. heterodoxa, and 2 Dendrobium cuthbertsoniis :-D. Most of the CPs were chosen by what I have multiples of and thought would do better with some cold. This way I can compare the similar sized plants growing in my main area and this chiller after a while and see if a larger setup is worth the cost and time.
  • #10
Looks like a pretty viable idea but it would be nice if you could get them a bit warmer during the day somehow so when the lights go off at night you get a natural drop. Is it possible to wire a thermostat into the cooler to achieve this? I have seen bare thermostats that could do that at hobby stores.

I work in a kitchen and we have a large air cooler in the retail area for drinks and such. I always thought it would be cool to make one of those into a large chill tank. Problem would be electrical costs.
  • #11
I know I could just set the entire chiller on a timer and turn it off for 6-10 hours in the middle of the day. The last few times I've unplugged the chiller it remembered my temp setting so it might be that simple. I just re-added the temp gauge so I let all the cool air out, once it gets back to the target temp I'll unplug it and run a little test and see how quickly the LEDs will heat it up.

There are already a good amount of the larger compressor setups running and they can work really well. If I get good enough results from this small scale setup I'll likely upscale it. So far nothing special but it hasn't even been a month yet.

The taller U. humboltii leaves are turning redder so those 4 LEDs may provide enough light for this species. Along with the H. heterodoxa coloring up some also. All in all I think the LEDs should be enough light for good growth but not the deep dark colors.
  • #12
I ran a test yesterday and here are the results.

Starting temp of 61 degrees at noon, I unplugged the chiller. At 5:45 PM it was 76 degrees when I turned it back on. The chiller reset to its default thermostat setting of 55 degrees and went to work chilling. During this off time there was a massive increase in the condensation inside the inner terrarium, I did not see any leaking out into the chiller but it was only for about 6 hours and may prove to be a problem if used long term this way.

I have no plans to provide a nighttime drop in temps at this time, I've reset it to 58 degrees the range I'm after and have resumed ignoring it :-D.

With a little toying around it would be pretty easy to get a raise in temps during mid day with this setup but I do have concerns about the condensation. I checked on it every so often and it was a steady gradual raise and then a steady gradual drop throughout the test, just what you would want.
  • #13
I had my first real problem yesterday, I mistakenly pushed the glass enclosure too far back and the inner cooling fan frosted over! Actual Ice! By the time I noticed there was a problem the temp was 80. Easy to fix and everything is already back to normal working order. The plants did not seem to mind the few hours of higher temps.

Condensation is a minor annoyance but so far that's it. Over 3-4 days I end up with about an ounce of water that leaks out the front door. I may just have to live with this.

I have seen no positive or negative results besides the increased light from the LEDs coloring up the plants a bit.
  • #14
This morning I pulled everything out for cleaning/removing dead pitchers. So here are some photos.

About a weeks worth of condensation, I may have found the magic spot were I don't get water on the table with until I open the door.

DSC_0037 by randallsimpson, on Flickr

Here is a close-up of the back drain, it was designed knowing water would pool up here.

DSC_0039 by randallsimpson, on Flickr

Side view.

DSC_0040 by randallsimpson, on Flickr

Front view and my makeshift door, a little painters tape + silicone = door apparently.

DSC_0041 by randallsimpson, on Flickr

Here is what the LEDs are doing to the U. humboldtii leaves, they were solid green before adding them.

DSC_0042 by randallsimpson, on Flickr

And for the first time I can see some green in the U. quelchii pot! So its growing, pretty fast compaired to the other ones considering how small it was. For those wondering it a net pot with some tree fern fibers sitting inside a taller pot sitting in a solo cup!

DSC_0044 by randallsimpson, on Flickr

Overall I think the U. quelchii is doing better in here the others are still about the same.
  • #15
Everything is still growing along fine, nothing special to justify the extra work to lower the temperatures. The chiller is working better than I would have thought.

Here is a another example of why I'm such a fan of these moonlight LED kits using daylight LEDs. Bout 5-6W of power for the entire setup lighting.

DSC_0160 by randallsimpson, on Flickr
  • #16
About 3 months later and its still working just fine. None of the CPs in there are doing better at 60 degrees than there "control" plants around 70-72. Due to this lack of growth I'm raising the temps up to 63 for the next few months.

A few pics from the cleaning this morning.
U. quelchii - It is really hard to tell from the photos but there is more green in there now. Still the 70-72 plants are growing faster.

DSC_0601 by randallsimpson, on Flickr

U. campbelliana - Added a bit back

DSC_0600 by randallsimpson, on Flickr

Dendrobium cuthbertsonii - Both of these are doing fine, a big part of setting this up was to grow this plant.

DSC_0602 by randallsimpson, on Flickr

H. heterodoxa - Doing nothing...nothing...the "control" plant at 70-72 is putting out new pitchers while the old ones die off all along staying the same size overall, this one is just doing nothing. Maybe its on vacation... Only reason the photo is in here is to showcase what the LEDs do to the pitches directly below the LED.

DSC_0603 by randallsimpson, on Flickr

H. pulchella - This one has put on some bulk

DSC_0604 by randallsimpson, on Flickr

The rest are doing nothing special for 3 months of time.