# Peltier Water Cooling Block for Chilling Substrate



## hydrophyte (Jun 5, 2009)

*Peltier Water Cooling Block for Chilling Substrate*

I have an idea in mind and maybe others will have some thoughts on this. I might also ask around on an overclocking site for more suggestions.

I hope to be able to chill the substrate of a terrarium enclosure to grow some special plants. My current idea is to use a Peltier with the chilling face attached to a water cooling block (like the one shown below) that is in turn connected to a length of rubber hose buried as coils in the substrate and with a small pump recirculating the chilled water as a closed loop.










There is a chiller assembly manufactured like this for use with small aquariums (http://img.dxcdn.com/productimages/sku_173562_3.jpg), but if I build it myself I can save about a hundred dollars. 

Does anybody have opinions about this? I hope to chill the substrate by 10-15F to about 60F. I hope that by just chilling the substrate, rather than the whole enclosure, I will get a greater drop in temperature with a smaller Peltier drawing less power. Are there any special concerns to have in mind for plumbing a closed loop with pump? I wonder about cavitation and other potential problems. Is there a best kind of small and reliable pump to use for this kind of thing?

Thanks for considering this!




.


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## hydrophyte (Jun 5, 2009)

I pasted the wrong link for that unit on Marine Depot. Here is the right one...

Chill Solutions CSXC-1 Thermoelectric Aquarium Chiller


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## MasterOogway (Mar 22, 2011)

I'd be interested to know how this works, if/when you get it up and running. I unsuccessfully tried to keep some _Peripatus_ species a while back, I just couldn't keep them cool enough in my house. If this works though, I'd be willing to try it again, cus those are some damned interesting inverts. Let us know! I'm sure the folks over at overclock.net (my other home away from home) would have some insights. A helpful link if you haven't been there yet http://www.overclock.net/f/62/peltiers-tec


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## zerelli (Sep 14, 2009)

I think it sounds like a reasonable plan. I wonder though, if you raise the false bottom just a bit and keep a "sump" under your substrate and then chill that water, I think you might get better cooling overall.


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## abIngenui (Oct 14, 2015)

Is there any reason you wanna use a peltier over, say, a mini fridge compressor? Peltiers are ridiculously inefficient (10-15%) and compressors can be upwards of 55%. So the small amount of heat the peltiers pulls from the tank will turn into about 10x the small amount, which you'll have to dissipate with a large heatsink and fan. 

A peltier would definitely work, I think, as the rate of thermal conduction through the glass into the soil should be slow enough for the peltier to handle. 

If you need something quiet, then obviously the peltier is the way to go, but if you want efficiency then compressors would be better.

Also, what are you trying to grow, if I may ask? I am curious


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## hydrophyte (Jun 5, 2009)

TarantulaGuy said:


> I'd be interested to know how this works, if/when you get it up and running. I unsuccessfully tried to keep some _Peripatus_ species a while back, I just couldn't keep them cool enough in my house. If this works though, I'd be willing to try it again, cus those are some damned interesting inverts. Let us know! I'm sure the folks over at overclock.net (my other home away from home) would have some insights. A helpful link if you haven't been there yet Peltiers / TEC


You should post pictures if get them again! Have you considered setting them up in a wine chiller? I will ask around on one of the overclock sites before I start to buy parts or build anything.



zerelli said:


> I think it sounds like a reasonable plan. I wonder though, if you raise the false bottom just a bit and keep a "sump" under your substrate and then chill that water, I think you might get better cooling overall.


I had wondered about that. Heat transfer would certainly be more efficient with that water circulating through. But a certain amount of crud always gets into the false bottom area, so it would also require a canister filter and/or regular cleaning, whereas a closed loop would stay clean. If I chill water under the false bottom I could also insulate the bottom of the enclosure so that it is drawing more heat from the substrate above. This water reservoir would need to be at least a couple of inches deep to insure that the intake and return would stay submerged. 



abIngenui said:


> Is there any reason you wanna use a peltier over, say, a mini fridge compressor? Peltiers are ridiculously inefficient (10-15%) and compressors can be upwards of 55%. So the small amount of heat the peltiers pulls from the tank will turn into about 10x the small amount, which you'll have to dissipate with a large heatsink and fan.
> 
> A peltier would definitely work, I think, as the rate of thermal conduction through the glass into the soil should be slow enough for the peltier to handle.
> 
> ...


The noise was one concern that I had for a mini compressor. That Chill Solutions chiller is also nice and compact. I might be using this for enclosures with 12" X 24" or similar small footprints and a compressor would be overkill for something like that. 

This is for growing terrestrial woodland mosses. I have seen that many of them grow best with temps in the 50s and 60s and they just stop growing when it gets warmer than 70F. So it can be challenging to maintain them in a regular indoor environment.


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## zerelli (Sep 14, 2009)

hydrophyte said:


> You should post pictures if get them again! Have you considered setting them up in a wine chiller? I will ask around on one of the overclock sites before I start to buy parts or build anything.
> 
> 
> 
> ...


I have heard of people using a mini-fridge and just looping water line through it.


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## Encyclia (Aug 23, 2013)

TarantulaGuy said:


> I'd be interested to know how this works, if/when you get it up and running. I unsuccessfully tried to keep some _Peripatus_ species a while back, I just couldn't keep them cool enough in my house. If this works though, I'd be willing to try it again, cus those are some damned interesting inverts. Let us know! I'm sure the folks over at overclock.net (my other home away from home) would have some insights. A helpful link if you haven't been there yet Peltiers / TEC


I had to look up what Peripatus were. Those are some fierce creepy beasts. What do they eat? What is their behavior like? Very interesting.

Mark


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## MasterOogway (Mar 22, 2011)

Encyclia said:


> I had to look up what Peripatus were. Those are some fierce creepy beasts. What do they eat? What is their behavior like? Very interesting.
> 
> Mark


I'll try not to steal your thread here hydrophyte  They were super cool, they eat small invertebrates, fruit flies, very very small crickets, small isos; they spit out this sticky glue to entrap the prey item, then run up and bite them, inject a venom/digestive enzyme cocktail, and then suck out the insides. They're a really old genus of animals, been around for hundreds of millions of years. They just need cooler temperatures then I was able to provide and they all died from being too warm, which made me sad inside. I'll try them again sometime, now that I have a better idea of how truly small they are, and how cool they need it. Some pics of the ones I had:


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## Encyclia (Aug 23, 2013)

That's super cool. Thanks for the info! Sorry about the hijack ;-)

Mark


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## hydrophyte (Jun 5, 2009)

This might be a good pump + reservoir combination for a closed loop chilling system. This kind of thing is more affordable than other pump options that I saw.

https://www.youtube.com/watch?v=DkmkGBdDiCk


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## Draikan (Oct 23, 2015)

I've only just started in this hobby. However, I'm an electrical engineer and I use Peltiers frequently at work.

Cooling is always tricky, so much easier to put heat in than to take it out. You basically have three options:
1) Evaporative cooling - think swamp cooler. This process isn't too powerful, is hard to control, and affects your air humidity a lot.
2) Traditional Refrigeration Loop - Like your refrigerator. This can be a pretty efficient process that is readily controlled. It's effective and refined. Unfortunately it's expensive, tiny systems even more so. If you had to go this route, and it could be a good option especially for a bigger tank, you'd probably want to look at hacking up a mini fridge or buying a reef aquarium chiller.
3) Peltiers - Initially this looks like the most hobbyist friendly option. You definitely can put together a very effective system that would work beautifully for cooling a viv. However, peltiers are COMPLICATED. Sizing the peltiers and all of their supporting equipment is not trivial. To get a decently powerful system you almost always need at least two separate fluid loops. This quickly turns into a complicated thermo/fluids/electrical problem.

I hope I wasn't too discouraging there. You definitely can do this with a peltier cooling setup. It would be really cool to see a method for keeping cooler vivs established. If you are comfortable doing general DIY things and take the time to set this up carefully, I'm sure you could make it work really well! I'd be happy to help explain calculations and show how to size things and explain how different heat exchanger/pumps/etc. will work together if you need it!

I want to make one more note about efficiency. Most Peltiers are pretty misused in a typical hobby application, this can easily result in 10-20% efficiency or less (which is awful). When applied carefully they have no problem performing into the 20-50% range. This application is actually particularly well suited to achieving decent efficiency because it only attempts to drop the temperature a few degrees from ambient (I'm just ballparking a 10-20 degree drop from ambient here).

Let me know if there is anything I can do to help with this!


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## hydrophyte (Jun 5, 2009)

Draikan said:


> I've only just started in this hobby. However, I'm an electrical engineer and I use Peltiers frequently at work.
> 
> Cooling is always tricky, so much easier to put heat in than to take it out. You basically have three options:
> 1) Evaporative cooling - think swamp cooler. This process isn't too powerful, is hard to control, and affects your air humidity a lot.
> ...


Yes I certainly would be interested to hear any advice that you might have to offer, although I wonder if it might not be more cost-effective to just use a small reef chiller in combination with a reservoir + pump for the closed loop. With all of the parts it will probably take a few hundred dollars to put together an effective Peltier system, right? Those radiator assemblies for the hot side alone are sixty seventy dollars at the cheapest. What do you think?

Do reef chillers have minimum operating temps? Could I chill the water down to as cold as 45F? If I could drop temps by that much for a few months of winter vernalization I could expand the kinds of plants to grow in these temperate terrariums.


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## Ed (Sep 19, 2004)

I've worked with enclosures that has subsurface cooling elements. One of the real big concerns your going to have is what the maximal temperate differences are going to be inside vs outside the enclosure. If the difference is too great for the chiller you choose then its not going to work well and you'll end up having to tear it down. The second is dispersion of the heat from the chilling unit. If the chiller heat sink is going to be in something like a cabinent aquarium stand then you will run into heat issues (to the point that it may not work at all) that even larger chillers may not be able to manage. 

Also keep in mind that many pumps use the water that passes through the pump to cool the pump and this is going to add to your heat load. 

Ideally your going to want to vent the heat away from the enclosure preferably into a large area to prevent the local heat build-ups. 

some comments 

Ed


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## hydrophyte (Jun 5, 2009)

Ed said:


> I've worked with enclosures that has subsurface cooling elements. One of the real big concerns your going to have is what the maximal temperate differences are going to be inside vs outside the enclosure. If the difference is too great for the chiller you choose then its not going to work well and you'll end up having to tear it down. The second is dispersion of the heat from the chilling unit. If the chiller heat sink is going to be in something like a cabinent aquarium stand then you will run into heat issues (to the point that it may not work at all) that even larger chillers may not be able to manage.
> 
> Also keep in mind that many pumps use the water that passes through the pump to cool the pump and this is going to add to your heat load.
> 
> ...


What kind of pipe or hose did you use for the heat exchange in the substrate? I plan to use PVC pipe. I know that plastic is less than ideal for heat exchange, but I hope it will work OK if I use tee and elbow fittings to split it into several sections running the length of the enclosure so that friction will be reduced and the water will have more time to linger in the pipe. 

Yes I am aware that reef chillers generally should not be enclosed in the cabinet. That Chill Solutions Peltier is supposed to be hung on the wall next to the setup, not in the cabinet.

For now I am pondering these options for two different general situations:

Smaller enclosure (12" X 24" or comparable footprint) substrate chilled with Peltier by about 10F below ambient temp
Larger enclosure (18" X 48" or comparable footprint) substrate chilled 10-25F below ambient temp with reef aquarium chiller
I hope that both of these might be feasible. A reef chiller on a small setup would be overkill.

A large setup chilled to 25F below ambient temperature would probably need to be built with an acrylic tank to avoid lots of water condensation problems.

I hope that a reef chiller will work with a closed loop setup. They are generally supposed to recirculate the aquarium water with tens of gallons or more of volume, but with a sump/reservoir and the water in the pipes this system will only have two or three gallons.


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## Draikan (Oct 23, 2015)

This will depend heavily on what you want to do. Just dropping your tank temp by a few degrees on warmer days is easy. Building a truly climate controlled enclosure that can reach 45 degrees while your home is warm will be hard, but DEFINITELY possible. I'll talk through how I would go about designing to maintain a significant temperature drop. The same process can be applied with less rigor for lesser effect. I should be clear that I'm partly brainstorming here, there are a ton of different ways to do this, as there are with any diy project. Just because I recommend one thing doesn't mean something else couldn't work. All of this will also have to reconciled with the requirements of the species you wish to keep, often this will mean some compromise. Again I don't want to discourage, but you are right to estimate a few hundred dollars for the system, it make take some fiddling and adjustment too.

This first step is the enclosure. If you want to maintain a temperature lower than ambient in the enclosure, you'll need to limit the amount of heat being absorbed from ambient. Tanks with thin glass will be the hardest, acrylic is a lot better, plywood is the best. Great stuff on the background is also a pretty good insulator. It will also be very helpful to mostly seal the tank and rely on internal circulation, you can't afford to have much warm air entering the tank. The heat created by the lights will also have to be VERY carefully controlled. This is tricky because when the tank is colder than ambient, blowing air across the lights is also blowing warm air across the top of the tank, heating it up. Fortunately, you don't need temps as low during the "day" when the lights are on, so that helps a bit. Carefully vented LEDs are probably the best choice here.

I cannot stress enough how important it is to insulate the tank. A glass tank will absorb heat roughly 5 times faster than an acrylic tank of identical dimensions. This means you need a chilling solution 5 TIMES more powerful. This makes small tanks with thin glass difficult to cool. However, this can be addressed by greatstuff and foam panels pretty effectively. wrapping the bottom of the tank would help a bit, but wouldn't be very attractive. As you said condensation can be a problem too, If the tank is cold it will be cooling the air around it, creating condensation on the glass. This is largely dependent on the humidity in your home, it may not be too large a problem. Luckily this is something we can calculate.

Once you know how the tank is insulated, you can figure out how much heat will need to be pumped out of the tank to maintain it's temperature. Now you can start to design the heat exchange system for the inside of the tank. This is the system that takes the very cold water from the chiller, and uses it to cool the substrate or air. For cooling the substrate there appear to be two choices. You can lay pipe in the substrate. This is attractive because it keeps the cold water separate from the tank water. However, as you said, plastic pipe isn't very conductive, this will block heat transfer and really make your cooling system struggle. I urge you not to underestimate this effect as it could easily prevent the system from generating any useful amount of cooling. Metal pipe will be far more effective here, but corrosion resistance will be an important consideration. The other option is to cool the water in the false bottom, either directly or by laying cooling pipe in the false bottom. I think this would be more effective, though you face the same issue of plastic/metal. The water in the false bottom should help distribute the cooling and buffer the temperature, both of these effects are valuable. Making this system effective at removing heat means you can use a weaker cooler.

You may also want to consider a way to cool the air in the tank. Probably this would be pretty easy to combine with the internal air circulation system. A water block like was shown earlier, combined with a finned heatsink in an air duct should be very effective. For best effect I would use both air and substrate cooling in the same tank, though this definitely requires a bit of experimentation, and I'm not familiar with exactly what your plants require.

Now that you have a well insulated tank with air and substrate heat exchangers built in, it's time to provide coolant (probably just water) to the heat exchangers. This is where we decide to use peltiers or a real chiller, depending on budget /availability/power requirements. I'll be honest, I've never used a reef chiller. It's possible that they don't operate down into the 45 degree range, and if you want to cool the tank to 45, the coolant will need to be even colder. So we will need to find out of the available chillers are even suited to this application.

The other option of course is a peltier cooler. The setup generally uses another seperate fluid loop and radiator to remove heat from the warm side of the peltier. The cold side is of course mounted to a heat exchanger that circulates the coolant being used in the tank. There are a few important things to understand here. When you apply power to the peltier electrically, all of that power is converted to heat and has to be removed from the hot side of the peltier. All of the heat the peltier pumps out of the cold side is ALSO present at the hot side and has to be removed. If the heat isn't removed effectively the peltier hot side will heat up. The peltier is effectively fighting against it's own heat that the hot side fluid loop is struggling to dissipate. This is why hobbyists generally see awful efficiency from peltiers, they don't adequately cool the hot side of the peltier. This is the hardest part of building a good peltier fluid system, but it can be done with hobbyist grade parts if you are careful! Once the heat has been removed from the peltier hotside into the fluid, it can easily be dissipated by a computer radiator.

Hope that wasn't too much info. I think I'll make some diagrams to better explain some of this and post them here. If you need help finding parts or doing some of the math I'm happy to help!


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## Draikan (Oct 23, 2015)

Could you tell us a little more about the plants/animals that might be kept in a system like this? I'm curious 

Do they need cool substrate or is the air temperature important too? Is it ok if the air is a bit warmer than the substrate? Is a temperature rise during the day acceptable? How much light do they need? Humidity?

How cool is the room the tank is typically in? Keeping the room cooler makes it way easier to reach the desired temperatures. If the room is going to be 80 while you try to hit 45 that could be nearly impossible.


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## Ed (Sep 19, 2004)

hydrophyte said:


> What kind of pipe or hose did you use for the heat exchange in the substrate? I plan to use PVC pipe.


There were two different variations. In the first case (for banana slugs) a pvc box was placed under the substrate and in the others pvc tubing was used. 

In the first case there were problems with the temperature due to a combination of the external temperatures, the heat from the lights and the heat from a 1/3 hp chiller under the stand. After cutting the back out of the lights, increasing the back opening of the stand and adding vent fans for the lights and the stand, the chiller was able to reduce the temperatures as needed. This then ran into a second problem where the difference between the interior and exterior was so great that condensation formed on the exterior of the enclosure. 
In the second case with the tubing, the same measures had to be taken but it turned out that the flow through the tubing wasn't sufficient to cool the substrate anywhere but directly adjacent to the tubing. The reason for this is because each bend in the line reduces flow rate. If you want to delve into that further I'd suggest a copy of Martin Moe's Marine Aquarium Handbook: From Beginner to Breeder. 



hydrophyte said:


> Yes I am aware that reef chillers generally should not be enclosed in the cabinet. That Chill Solutions Peltier is supposed to be hung on the wall next to the setup, not in the cabinet.


Don't underestimate the impact even the local external temperature can have on the end temperature. A



hydrophyte said:


> A large setup chilled to 25F below ambient temperature would probably need to be built with an acrylic tank to avoid lots of water condensation problems.


The above enclosures were acrylic and that didn't prevent condensation. 



hydrophyte said:


> I hope that a reef chiller will work with a closed loop setup. They are generally supposed to recirculate the aquarium water with tens of gallons or more of volume, but with a sump/reservoir and the water in the pipes this system will only have two or three gallons.


They do work but you have to be aware that the external conditions can be a real issue. 

some comments 

Ed


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## cam1941 (Jan 16, 2014)

Here's one of the more innovative vivs I've come across that may help you with your design...

Cool vivarium - Orchid Forum by The Orchid Source


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## hydrophyte (Jun 5, 2009)

Draikan said:


> Could you tell us a little more about the plants/animals that might be kept in a system like this? I'm curious
> 
> Do they need cool substrate or is the air temperature important too? Is it ok if the air is a bit warmer than the substrate? Is a temperature rise during the day acceptable? How much light do they need? Humidity?
> 
> How cool is the room the tank is typically in? Keeping the room cooler makes it way easier to reach the desired temperatures. If the room is going to be 80 while you try to hit 45 that could be nearly impossible.


Thanks again for considering my questions. I'll go through your post above and try to respond with more detail.

I have two kinds of setups that could benefit from some kind of chiller system. I have been growing native North America mosses with some success in terrariums, but I have found that most grow best with temps in the 60s and often start to decline or grow less consistently at >70F. For these I can get good results if I can drop the substrate temperature by just 10-15F. 

I have also been trying out various other native forest plants in terrariums. I have found a selection of evergreen groundcover species that can adapt OK in terrariums, but I think I can expand this list for special terrarium plantings if I can find an effective way to seasonally chill down into the 50s for winter vernalization. 

Indoor temperatures for these settings will usually be in the low 70s. 





















Ed said:


> There were two different variations. In the first case (for banana slugs) a pvc box was placed under the substrate and in the others pvc tubing was used.
> 
> In the first case there were problems with the temperature due to a combination of the external temperatures, the heat from the lights and the heat from a 1/3 hp chiller under the stand. After cutting the back out of the lights, increasing the back opening of the stand and adding vent fans for the lights and the stand, the chiller was able to reduce the temperatures as needed. This then ran into a second problem where the difference between the interior and exterior was so great that condensation formed on the exterior of the enclosure.
> In the second case with the tubing, the same measures had to be taken but it turned out that the flow through the tubing wasn't sufficient to cool the substrate anywhere but directly adjacent to the tubing. The reason for this is because each bend in the line reduces flow rate. If you want to delve into that further I'd suggest a copy of Martin Moe's Marine Aquarium Handbook: From Beginner to Breeder.
> ...


Thanks also for these additional thoughts Ed.

I like to use pendant LED lighting for my setups. These impart very little extra heat. I kind of hate having light strips skating around on top of the enclosure when I try to access. 

I think I can plumb these things and avoid 90 degree bends, except for the tee unions that split the flow into several pipes running the lenght of the substrate bed, but here the volume inside the pipes will increase several times. So I hope the friction will be less of an issue. 

For setups chilled more than 15F below ambient temp I will need to use acrylic or plywood enclosures. Regular pink styro insulation can also work well with epoxy resin + fiberglass construction.


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## Ed (Sep 19, 2004)

Your lower external temperatures will help a lot with your goals. We had to try to keep those enclosures working when the external temperatures in the viewing area could reach +85F. 

Sounds like a plan but again that book I suggested above goes into the best optimum ways to run plumbing for water circulation and can be had very inexpensively. 

Some comments 

Ed


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## hydrophyte (Jun 5, 2009)

I got one of these things slightly used and cheap...

Hydro Series™ H110i 280mm Extreme Performance Liquid CPU Cooler

The most important aspect of increasing the Peltier efficiency is taking the heat from the hot side. This radiator is supposed to work well. 

I got some more advice and I think I will abandon the idea of using water pipes buried in the substrate and instead just cool the air around a second radiator on the cool side and suspended inside the enclosure. I hope that if the enclosure just has a little bit of passive ventilation, cool air will sink down from the radiator to flow across the soil surface. As I mentioned earlier, I only need an approximate 10F drop in the area around right around the plants. 

I might try to put this together sometime pretty soon for my setup with the elk antler. The mosses are looking really good in there right now, but I suspect they will start to flounder when the basement shop starts to warm up again.


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## Draikan (Oct 23, 2015)

Were you able to continue working on your chilling setup? I'm interested to hear how it went!


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## hydrophyte (Jun 5, 2009)

Draikan said:


> Were you able to continue working on your chilling setup? I'm interested to hear how it went!


I haven't yet, but I still have the box of parts here. maybe I can get to it later this spring. 

Because of the potential for failure with a recirculating liquid heat exchange, I'm currently considering the idea of positioning an aluminum block attached to the cold side over one side of the enclosure on the inside. I was advised that this might cool the whole substrate surface by creating a downward current of cold air that will tend to flow outward and also stay inside the tank.


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## Draikan (Oct 23, 2015)

That makes sense. I could see that working, especially if you just need to chill close to the substrate.


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## hydrophyte (Jun 5, 2009)

Draikan said:


> That makes sense. I could see that working, especially if you just need to chill close to the substrate.


Yeah it might actually be more effective to cool the growing area with sinking chilled air, rather than trying to draw heat out of a mass of substrate. 

These native mosses are really neat when you can get them growing, but regular room temperature is a little too warm for them.


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## goof901 (Jan 9, 2012)

I made a peltier cooler to cool my viv (http://www.dendroboard.com/forum/parts-construction/82510-thermoelectric-cooler-cool-viv.html).
The biggest problem I ran into was that the heatsink for the cold side inside the viv generated a lot of condensation, sucking the humidity out of the air. That might be a problem if you're trying to grow mosses that require high humidity, especially if you plan on running the cooler 24/7. I can't say how much the humidity dropped (I never measured it) but I noticed that if I left the cooler on for a few hours, the leaf litter at the bottom would be quite dry by the end of it, even if it started completely soaked. 

Just something to consider.

I was cooling from about 80-85 to 72-75.


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## Ravage (Feb 5, 2016)

I have use liquid CPU cooling for 15 years, once I tried Peltier with a liquid block on the hot side, but the efficiency and complexity hardly made it worth it for the slight decrease in temps. That's: high density heat exchange over a tiny footprint, but still points to the difficulty: complex systems will either fail, or must be designed with redundant components further increasing complexity and reducing efficiency. (BTW if you want to super cool a CPU, use liquid nitrogen, it takes very little, it is complicated for each session, but in the end: few moving parts- High efficiency)
But back to the viv, as is becoming apparent from the multiple paths and suggestions- you will always fight an uphill battle trying to keep a small enclosure at a different temp than the large mass of the room itself. This is true for both cooling and heating. Heating a viv room is easier to do at the room scale than the vivarium scale. The same is true for cooling. Why not cool the room (Walmart sells cheap air conditioners)?
A basement would seem perfect for velvet worms, although most of us don't have basements. I live in Colorado at elevation where cool is easy most of the year.
But even making a refrigerated enclosure in which to place the viv would make for a more easily controlled system than creating temp. differentials inside an enclosure that then sits in a warm room.
Just a couple of ideas. In any case, good luck with your living fossils- they are super cool. Horror show eating habits though.


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## Ravage (Feb 5, 2016)

I found this video, which perhaps some of you folks have seen, but it demonstrates what I was postulating earlier. This Lady keeps her velvet worms in a critter keeper in a wine cooler. Not the best for display, but workable and controllable.





They just keep looking neater and neater, I'm think i'm going to go watch some more Peripatus vids.
Again, Best of Luck.


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