DIY chiller

The past couple of days have been real hot here and ive been panicking watching my tanks thermometer go up and up [smiley=shocked2.gif]

So far ive managed to keep the temp under control by floating bottles of ice in there but i would love a water chiller only the cheapest one i could find are around 3 to 5 hundred and im a poor student

At my work (camping store/repair shop) we have thermo-electric eskies and more importantly the spare parts for them....For those of you who dont know how a Thermo Electric Cooler (TEC) works theres basically two plates with semi-conductor between them, you run current through it and one side gets really hot the other really cold, you attatch big ole heat sinks to each side having the cold one inside the esky and the hot on the outside with a fan to cool it...

My plan was to have the cold heat sink in the water and the hot above the water line with a small computer fan to cool it. The whole thing should run off 12 volts.

I am aware that you cant have metal in a tank or it will corrode producing nasties that will kill fish. However if the heat sink was alluminium and all other corrosive metal parts sealed in silicone or sumthing would it be okay??

Has some thing like this been done before? Becuase right now i feel soo smart [smiley=smart.gif]

Any feed back or ideas would be much appreciated

 

i wouldnt put any metal in the tank Yinski sorry...

What i would do though is run a flexible tubing on your cold heat sink and with a small pump run water through the tubing. You dont have that problem in Sydney but here in canada as an inexpensive pool heater we use black flex tubing and run it on the roof of our houses or our sheds.. twearl it around the more we can and run the pool water in it... the heat from the sun and the roof top heats the water and then returns in the pool, you can barelly put your hand under the return water its so hot. So i would give it a try.. fill up that cold heat sink with as much tubing as you can, use a low flow pump so the water has time to get cold and you should be getting cold water coming out...

Anyways just an idea... not sure if you got me but if you didnt let me know and ill try to explain it better or make a drawing.

Marc.

 

The IceProbe by Cool Works is a TEC based chiller. While the company rates it for tanks up to 55 gallons, from what I have been told it is in effective on tanks larger then 20 gallons. Which is to be expected as it contains only a single 55 watt Peltier.

There are some problems with TEC based cooling systems that need to be adressed. Firstly, moving the heat away from the hot side of the device. While generally a heat sink is applied, this is often not effective and the whole device heats up. Some of our lab equipment is cooled via TECs and none employe heat sinks. Instead they use a water jacket and a radiator mounted far away from the device.

The second issue is powering the device. While it is true that they opperate on 12 volts, each cell draws between 5 and 6 amps. To achieve maximium cooling it is better to apply multiple cells. Which in turn increases the power consumption. Your average 12 volt power supply is not able to produce enough current to opperate these devices. Go look at what you have around your house, you will find most of them rated for less then 1500 mA.

Sorry to rain on your parade. But for what you would spend developing an effective TEC based chiller, you could by a small AC unit and modify it. I have seen small 500 btu units avalible in the states for less then 100$.

 

Yinski,

Have a look at this, it's a Peltier device drink cooler http://oatleyelectronics.com/peltier.html

I have one of these at home which has never been used ( too lazy ) so if you want it I can send it over to you

John

 

Thanks a ton JohnO for the offer but i've already got the TEC from my work for a couple of bucks, its actually the spare part from a product similar to the one you linked to.

Well i've been thinking about the corrosion issue all day...'maybe i should coat it with something'...'what should i coat it with'...'maybe if i constructed the entire thing out of a non-reactive precious metal like platinum'

Crazyness aside the only remotely viable option besides m_lacom99's idea of the tubing that ive been able to come up with is coating with the submerged heat sink with glass as it is completely non-reactive and can be melted with a LPG blow torch.
This would be a similar idea as aquarium heaters employ to keep the metal elements seperate from the water.

Of course i could do all of this and find out that it is completely ineffective for some of the reasons stated by jay; particularly the whole unit heating up as a result of not dissapating the heat from the hot side well enough as this has been a major problem in my past experiences with TECs.

But i love to do this type of thing and it usually does blow up in my face a few times before it works : like taking a shock from the main pin of my 25 thousand volt generator i made

Will post any thing i can come up with here. Thanks alot for the feedback though

 

Wouldn't running high volume fans (not computer fans) over the surface of your tanks water a better alternative for cooling? I have a 6" 220V fan (I guess you'd have 110v in the US).

This would;

1. Agitate tank surface area therefore incite gas exchange.
2. Increase evaporation of water thereby cooling the tank. In my setup it lowers the temp by 1-2 degrees farehnheit.
3. Increase required rate and volume of kalwasser top-off making calcium supplementation more aggressive (increasing ppm being fed to tank).

IME...

 

I have thought of using fans for cooling via evaporation however this would increase the the regularity of water changes would it not?

Me = Lazy [smiley=sleeping.gif]

Also all this would entail is a couple of fans sitting there blowing away........Wheres the challenge ;D

 

Keeping your reef thriving is the (expensive!) challenge. Heck if you are lazy and can afford to buy all the gadgets why not? Go on dude .... life's ok...