DIY chiller

[RobM]

Hey,

Im planning on making a DIY chiller for a couple of my tanks and would like your help and advice.

My tanks currently have internal filters in them, but I know that these will not be powerful enough to transfer water between the tank and the chiller. So one option could be to add pumps to the tanks. One problem with this is that it will mean I am running an excessively large amount of equipment (2 filters, 2 pumps and a chilling unit). A second problem could be the amount of turbulence in the water caused by a filter and pump (my newts wont like that)

So second option. I could use external filters to move the water between the tank and chiller. I've never used external filters in an aquarium only ponds, so don't know really what to make of them. I am put off by the price of them in comparison to internal filters and seeing as I am DIY'ing the chiller to save money it could defeat the purpose of the project. What do you think of external filters?

Third/forth option. Instead of the aquarium water passing through the chiller, I could pass other water through the plumbing. I could potentially use one pump for this and pass the cool water through both aquarium tanks to give a cooling effect. This could be a simpler and cheaper method to set-up, however as the water is only being passed through, I believe the cooling effect on the tanks will be much less than passing the aquarium water itself. I could increase its effect by increasing the surface area of the water being passed through, but I don't think I could get it to cool as much as I could, using the aquarium water.

Any thoughts and ideas?
Thanks,

 

[CherryBlossom]

interesting.. I too am looking at D.I.Y chillers for my 2 tanks partial water changing is not helping to keep them cool... and neither is my icing method. But I am not very clued up on it all so I'm gonna keep an eye out on this thread and see what is said

 

[BikerHewett]

Hi, have you thought about using Peltier Thermoelectric Cooler devices? The plate freezes to icy cold in just a matter of minutes, or alternatively, reverse the polarity and heats it. Control the amount of current to control temp. Works on 12v supply.

Les

 

[Jennewt]

Peltier coolers are available and relatively inexpensive. But from what I've heard they only make a small temp difference, at best. Not effective on large tanks. If Rob's tanks are small, this might be a reasonable option.

Rob - will the chiller be an actual aquarium chiller, or a refrigerator? This could certainly make a difference in the plumbing. Do you want to keeping the plumbing for the two tanks separate? Are the tanks positioned one above the other, or on the same level?

I don't think the 3rd option will be effective - not enough contact. In my opinion, external canister filters are great, but they are generally too powerful for small tanks. It would help to know the size of the tanks.

 

[RobM]

Hi, have you thought about using Peltier Thermoelectric Cooler devices? The plate freezes to icy cold in just a matter of minutes, or alternatively, reverse the polarity and heats it. Control the amount of current to control temp. Works on 12v supply.

Les

Do you have an example of such a device that can be used? (and available in the UK)

Rob - will the chiller be an actual aquarium chiller, or a refrigerator? This could certainly make a difference in the plumbing. Do you want to keeping the plumbing for the two tanks separate? Are the tanks positioned one above the other, or on the same level?

I don't think the 3rd option will be effective - not enough contact. In my opinion, external canister filters are great, but they are generally too powerful for small tanks. It would help to know the size of the tanks.

The tanks are probably about 60 litres each.
I was thinking of using a electric cooler that CherryBlossom suggested in another thread. Campingaz Powerbox 28 Deluxe + Mains adapter Combo: Amazon.co.uk: Sports & Leisure

The tanks will be positioned one on top of the other (on shelves). I want to keep the filtration and water separate in both tanks, I do not want to mix their chemistry or risk disease spreading if one tank gets into problems.

 

[Mac Myers]

The internal filters will raise the temperature and make chilling harder (I own one). Thermoelectric cooling devices are, in my experience, pretty inefficient. May work for one 60 liter tank but I'd be interested to hear if you could pull it off with 120 liters.
One thing I have learned. Water stratification inside the chiller is an issue. An airstone can take care of it however.

 

[CherryBlossom]

£4.51 Free Ship 100W TEC Thermoelectric Cooler Peltier 12V - Wholesale £4.11

heres those coolers BikerHewett spoke of.

 

[RobM]

Thanks, I already have some peltier plates though. The problem is I am unsure how to safely use them with a heatsink and fan using mains electricity.

 

[SludgeMunkey]

Thanks, I already have some peltier plates though. The problem is I am unsure how to safely use them with a heatsink and fan using mains electricity.

You can't use peltiers off mains without a transformer. Peltiers use DC voltage ( most consumer grade being 12 to 30 VAC). Mains is AC 220 volts for most of the world, 110-125 VAC in North America.

As a professional electronics technician I must strongly advise against DIY electrical projects for use with aquaria by folks unfamiliar and properly trained with electricity. It only takes one milliamp to stop your heart...permanently...less to scramble your pets.

I highly suggest the caudata culture articles on cooling as there are many excellent methods for all skill levels and budgets featured there.

Also a few moments with the forum search function will provide a wealth of info on this topic.

 

[RobM]

You can't use peltiers off mains without a transformer. Peltiers use DC voltage ( most consumer grade being 12 to 30 VAC). Mains is AC 220 volts for most of the world, 110-125 VAC in North America.

As a professional electronics technician I must strongly advise against DIY electrical projects for use with aquaria by folks unfamiliar and properly trained with electricity. It only takes one milliamp to stop your heart...permanently...less to scramble your pets.

I highly suggest the caudata culture articles on cooling as there are many excellent methods for all skill levels and budgets featured there.

Also a few moments with the forum search function will provide a wealth of info on this topic.

Yep, thank you, that is why I planned to use a cooler box and pump water through it.

 

[Mac Myers]

As a professional electronics technician I must strongly advise against DIY electrical projects for use with aquaria by folks unfamiliar and properly trained with electricity. It only takes one milliamp to stop your heart...permanently...less to scramble your pets.

Heh... I was actually wondering if you could just wire this bad boy up to a DC supply and hang it in the tank. Just kidding (sort of... I'm pretty dumb). Electricity and I have a rivalry that dates back to my toddler days when I stuck a piece of metal in a wall socket and goes right up to last weekend when an outboard motor spark plug lit me up.
I'll leave those things alone.

 

[BikerHewett]

Although I agree about electricity and water I don't think there is an issue here. First the votage supplied to the cooler and fan needs to be no more than 12v dc and second there is no need for the plate(s) to be in contact with the water. My thoughts were that the plate could be bonded to the glass on the outside. Also if really worried about water and electricity use a RCD on the mains converter. After all we all know that you should disconect the mains before putting our hands in a tank with mains powered filters / heaters but how many do.

 

[SludgeMunkey]

Although I agree about electricity and water I don't think there is an issue here. First the votage supplied to the cooler and fan needs to be no more than 12v dc and second there is no need for the plate(s) to be in contact with the water. My thoughts were that the plate could be bonded to the glass on the outside. Also if really worried about water and electricity use a RCD on the mains converter. After all we all know that you should disconect the mains before putting our hands in a tank with mains powered filters / heaters but how many do.

I agree with you, however the safety issue here is current. While there is a low voltage draw on a peltier, they draw a high current.
As stated before, it only takes a fraction of an amp to kill.

Another issue with peltiers is heat bleed off. The intense heat generated on the hot aside of the plate must be dealt with. Ultimately you need a chiller for the chilled for the chiller which is counter productive.

 

[BikerHewett]

I do not believe that 12v would be able to provide enough potential to overcome body resistance to drive a sufficient current to cause harm. However my main point is that they will not be in contact with water (Glass is a good insulator) and if located on the rear of tank would be out of harms way. Yes they would need to be cooled but that is true of any cooler. Lets not forget the icebox that Rob M is thinking of using uses a Peltier system powered from a 12v car battery plus external mains transformer. All I am saying is why pump water from a tank to effectively another tank and then back again when you can cool it at source.

 

[SludgeMunkey]

Trust me when I tell you it is dangerous to the untrained. Even a 12 volt car battery will knock you. As I stated previously, the voltage is not the issue. The amperage(current) is. A car battery may only be 12 volts but they can dump 30 amps or more depending on the type of battery.

115-220 vac at 1 amp (standard mains) can and will kill just a sure as 12 vdc at 1 amp will.

 

[BikerHewett]

A 12v car battery can supply in excess of 200 Amps. 12v just does not have the potential to drive a current of significant magnitude througe a human body even if the person is wet. Please google "electric shock" and look at the Wikipedia article. Gi
ven a body resistance when wet of 1000 ohms aand a voltage of 12v dc only 12mA will flow. Where you get a fatal current of 1ma dc from I don't know unless you are talking about a direct conection to the heart. As pointed out in the article a dc current of between 300 mA to 500 mA is required to cause a fatal shock. Many people have received an electric shock from a car ignition and yes the voltage is much much more than 12 v but due to source impedance, body resistance and duration you do not see car mechanics being killed. At work I had to attend a course on working at height - their definition of working at height is any height above 6" (150 mm) - above this height a risk assesment is required. Why can't we give people credit for common sense. By your logic how is the chiller any safer? Why should a device connected on the outside of the tank come into contact with the tank water? What about mains powered lights that fit across the top of a fish tank (I have one) where I could very easy touch both a live 240 v ac supply and tank water at the same time if changing the tube / light bulb. Lets also not forget that you also need a path to earth for a current to flow.