Hi
I've tried several systems with little long term success.
of course I'm in Florida so most of the year is way above desired temps.
They make refrigerated units for this purpose but seem to be expensive.You might visit some of the websites and see how it's done.At least you'll get some ideas on how far you want to pursue the idea.
Gary

Thanks Gary,
The terrarium would be in an air-conditioned house, but still the temp gets up to the low 80's indoors in summer. Add lights to that and it would go way up. I haven't seen anything on the internet anywhere about chilling or cooling terrariums. It probably wouldn't really feasable for me anyway, since I've got so much power consumption as it is. I'm not thrilled about adding a refrigeration unit to the total. I'll just have to stop fantasizing about growing Draculas and Lepanthes.

Hi Eukaryote -

I remember reading somewhere about a guy who picked up a cheap dorm refrigerator. He drilled two holes in the sides for aquarium tubing and inside had a very very large container that held cold water. He hooked up a pump so that the water circulated from the terrarium to the fridge and back.

I've always wanted to try this.

Some people who grow highland Nepenthes put frozen liter bottles into their terrariums at night to drop the temp, but it sounds like a lot of work.

Good Luck

WildBill

Wildbill
I've attempted that type of system on an aquarium and found that about 10 degrees max was the drop I would get.
I even ran the tubing through a freezer rather than a fridge.The system got so complicated as automatic circulation was required to prolong the cold exposure and when the temps got above 95 the drop was around 5 degrees.
I've also tried the chillers made specificly for that purpose.Again,there was a drop in temp but not enough to
justify the expense.
Of course with a terrarium the effectiveness would be even lower
The only practicle way to do this is with a refrigeration unit with internal air circulation.These units are not only expensive to buy but to operate also.
I once had a n oportunity to get a grocery store type refrigerator with glass doors.This would have to modified to higher temps.I do feel that it would have worked but the space would not have justified the expense.IMO.
In colder climes you might try a cool greenhouse with regular air conditioning during the summer.The savings realised from lower winter temps could be applied to summer cooling.??
Gary

That's what I was afraid of. I knew it had to be difficult, or more people would have these kinds of setups. I thought about setting up a grow-room with a window unit and artificial light, but that's a lot of electricity. I bet it would be really expensive to cool a greenhouse here during summer too. Well, thanks for the info. and suggestions. I guess I'll just have to wait until I move to the pacific northwest to have these kinds of plants.

Just thinking out loud here, but I wonder if you could build some sort of radiator system? set up a pump moving water from the bottom of the tank up through a small radiator (Motor Cycle radiator?). Have a 12V Fan blowing through it. You may not get the temperature much below room temperature, but you wouldn't be dealing with the 80's.

I have been spending a great deal of time thinking about this, and here is a thought. If you are dealing with a terrarium with a false bottom holding a resevoir of water, you could perhaps use this $100 aquarium chiller:

http://www.premiumaquatics.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=PA&Product_Code=IPWC-50&Category_Code=Minichill

It would cool the water down and thus transfer the cold to the terrarium. I have some thoughts on making this even more effective, but it is an idea that I am still developing, and I don't want to let the cat out of the bag until I've got it working and tested, to see if it is really effective. If you are interested, email me and I fill you in on my thoughts.

I'm not sure how large a terrarium you are talking about but I have made a small one (10 gal size) from a coleman portiable electronic cooler. This runs on a 12 volt adapter (included with mine) and keeps the unit avout15 to 20 or more degrees F. below room temps. I use 23 watt compact floresent lamps and my pleuro's are very happy. I know that replacement chiller systems for these type coolers are ava. Perhaps severial of these could be installed in a panel of the terrarium.

Have you checked in at the orchid forum? Folks there grow pleuros in terrariums successfully.
Diana

I'm glad to find this topic here. I have been trying to develope something like this but for a completely different application. I love plants and have run in to this problem in the past and now again with my other hobby (insects). I'm not sure if any of you are familiar with thermoelectric modules but I believe they are the answer to the prayers of many of us. This technology has been around for about 80 years or so and it's nothing new. They can either cool or heat. The same unit can do both by simply reversing the polarity of the electric current. They are inexpensive (about 10-15 dollars each) and supposedly easy to apply. I'm in the process of making something using these. The target temperature for my application (not plants) is 77 degrees. There is another little godsend available that I've also come across. I just purchased one of these. The Medusa HC-100. It's a temperature controller. You can buy a single unit (approx $140.00) to control a single device (either a cooling or heating device) or you can buy another model (approx 190.00) that can control both a heating and a cooling device. These units have thermostats and temperature probes. They are accurate to + or - 1 degree and have a two digit temperature readout. I'm not quite done with what I'm trying to do but if all goes well, I'll be happy to post here and you can bet I'll be making more for plants. I'll try to keep it simple for all of us when I do post.
Another thing that I've come across is info on all glass aquariums. These are quite simple to make yourself. Making them your self you can customize them and save quite a bit in overall price. I have links if anyone is interested. Please e-mail me and I'll send you what I have. Good luck to everyone.

Hugo

Bugfreak, all of that sounds very interesting. Could you tell me some more about the thermoelectric modules and glass aquariums at bananasmangos@hotmail.com. thank you

Leafbrain, Thermo Electric modules are also known as TECs(thermo electric coolers), and are more properly known as Pelletier junctions or heat valves. They can effectively cool things down into the 32deg and under with the application of water.

Overclockers(people who speed their computers up past stock Mhz) use them to effectively keep temperatures down, smaller refrigerators(like that Coleman cooler) use them for effective heat transfer as do other pieces of equipment. As Leafbrain said, they are relatively cheap and if you can find a way to transfer the cooling to your terrarium, it could work.

Sam

Too bad a basement's not an option [at least I'm assuming you don't have one]. A number of orchid growers I know have great success with the cool loving orchids by growing in the basement where it stays markedly cooler year round than above ground. Be interested to hear how things turn out for ya.

Good luck and Happy growing!
: )

I've given up on the idea pretty much. I'm planning on sticking to intermediate/warm growing plants now. Even our basement gets warm in the summer, and with plant lights running, it would be too much. It's still something I would like to try in the future though.

I still think about this issue from time to time. Ever since this post came up last year. Unfortunately all my ideas tend to involve ductwork, fans, and making holes in outter walls...a bit drastic. But it's fun to think about anyway.

What about the simplest of all solutions? A dedicated room to grow them in tanks...and a small window AC unit on a timer? Seems like you could figure out how cold the room would have to be to get the tank down to a certain temp and then use the timers to keep the temp there for x amount of time. Or what about just putting the tank in front of an AC window unit? A small room could be closed off and the cold would build up quickly. Just a thought...

AArg! I had typed a whole response and then my 6 month old boy hit some key and erased the whole thing! here goes again. . .

I've been thinking about this a lot too, and I think that I would create a large false bottom and fill it with ice. that is, I would freeze water in milk jugs and put those in there, then fill the gaps with distilled water, and use that water to mist the terrarium. my theory is that the ice would cool the water a lot, and misting with such cold water would cool the terrarium nicely. You would have to be able to access the false bottom, to remove the milk jugs as they thawed and add new frozen ones while the old ones refroze. Does anyone else think this would work? I think it would be high-maintenance, but I wouldn't mind doing it, personally. the only other thing I can think of is an air-conditionned room, like Mr. B said, but I think my idea is cheaper. What say you?

Yep...I think that's a good idea. There would be some issues with trying to figure out the logistics of it and, like you said, high maintenance. But the theory is good. What about dry ice? Instead of using milk jugs (which would necessitate raising the floor of the viv too high, IMO)...just leave a slot where you can insert some pieces of dry ice. That would certainly cool the water down for the misters...too much maybe? Then there's the extra CO2 that the plants would like.

Well you can get those cute little 1 L milk jugs at convenience stores, and those would take up way less space than the 4 L (1 gallon) ones. Cheaper than getting dry ice though! but i bet the plants would like the CO2. . .

Lepanthes are my favorite type of orchid and I have been trying to grow them in Florida. I tryed several mini fridges and the motor burnt out on all 3 within a week! Finally, I found a hands down winner for growing cool growing orchids etc. I ordered a large thermoelectric cooler off ebay $27 and didn't have to pay shipping because the guy was in Orlando too, what a deal:) I took the top off the cooler. Next I broke the bottom out of an aquarium I had and set it on top of the cooler and glued it in place,sealing the gaps with wood panels. I have had ten different lepanthes species growing in there for two monthes, and they have all put out new growth, and all but two have flowered. For the really cool growers keep them toward the bottom which is always 48-58. The upper part is just a couple degrees lower than the room temp. Just thought I'd share what has worked for me.
-Michael

Hmmmmmm. . . I think I'll try that in the future! What brand is your cooler?

The cooler is coleman, and it is I think 40 gallon. I was lucky with the price as shipping would have been an additional $30. The thing really does work though, I am really surprised:)
-Michael

That's an interesting prospect. I wonder if you could set something like that on a timer to cool the plants down at night and then let the temps rebound a little during the day? I guess the lights will do that anyway to a point. So many interesting ideas...

If you don't mind the expense, get one of those florists display cases, where they keep the flowers in cool temps, I'm not sure if they hve small ones, I've been toying with the idea because I love Cymbidium orchids and they have to have cool nights to bloom... fat chance here in Guam. I grew them in California and I miss them!
Ana :)

Not the best pics...it has also been filled in quite abit since these were taken...but this is my tank that I grow my Dracs, cooler masdies, & pleuros in. No special cooling needed so far, but the A/C is on in the room pretty much 24/7...J

Would have helped if I posted the link, huh? J

Here is a link that might be useful: Link to gallery post