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Peltier cooling

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RobM

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Hi,
I want to make a peltier cooling device, but really have no clue how to do the wiring.

I want to use 4 of these peliter plates: https://www.electro-tech-online.com/custompdfs/2010/06/TEC1-12706.pdf
Attach them to a computer fan and heatsink and run everything off a mains power supply. I know this will require a transformer which is fine.
Can anyone help me avoid setting fire to my house and give me any info that might help me to do this?

Thank you!
 
4 of them? That's 25 amps of current, you'd need to use an entire extra ATX supply, and with four in series the wiring is the least of your concerns, you'll have to deal with condensation on the cold side, and the ohmic heating alone may prevent four from being used like that. Why are you trying to implement such an absurd cooling scheme? Good machines run cool from sane design and low power usage not massive cooling.
 
As cool and simple as peltier cooling seems, there are inefficiency issues and other complications including the fact that you have to remove the heat from the hot side to keep it from overheating. You have to "cool the cooler" in a sense.

If for some reason you really do need the cooling, phase change or water cooling will probably work better.
 
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You will need a very large heat sink as well. You will have the heat being drawn off of what ever you are cooling plus the near 25 amps at 14 volts to contend with as well. You could be looking at over 400 - 450 watts of heat that needs to be dissipated some how.
 
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What is heating up the water to the point of being concerned with having to need to cool it?
 
It might just be temperature control for the water in the tank.

Didn't somebody a while back doing the same thing say that just blowing a fan across the surface of the water to increase evaporation worked quite well? And I think someone else also added that if you can circulate the water in the tank, the fan will work even better.
 
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What is heating up the water to the point of being concerned with having to need to cool it?
Peltier effect -> one side transfers heat to the other side. One side goes cold, the other hot, if you can move the heat away from the hot side, you can cool things down.

Didn't somebody a while back doing the same thing say that just blowing a fan across the surface of the water to increase evaporation worked quite well?
You only get a minimal decrease on the ambient temperature using evaporation with fans.
 
Peltier effect -> one side transfers heat to the other side. One side goes cold, the other hot, if you can move the heat away from the hot side, you can cool things down.

Perhaps you misunderstood TCM's question..

IIUC, I'll rephrase:
What outside influence is causing the aquarium water to be heated above the acceptable level and if possible can that outside influence be removed or reduced?

Another question:
What temperature do you intend to keep the aquarium at, and how far from ideal do the levels swing either way from outside influences?
 
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Perhaps you misunderstood TCM's question..

IIUC, I'll rephrase:
What outside influence is causing the aquarium water to be heated above the acceptable level and if possible can that outside influence be removed or reduced?

Another question:
What temperature do you intend to keep the aquarium at, and how far from ideal do the levels swing either way from outside influences?

Sorry please excuse me. The summer heat is causing the water to go above an acceptable level, that unfortunately cannot be removed. I do have an air conditioning unit, but I cant have it on 24/7.

The water goes up to at least 24, if I didn't use other cooling methods I think it would go up higher. Ideally I would like it below 21 (although keeping it constant at 21 would be on the limit of OK).
 
You did not say if this was a salt or fresh water. I am assuming fresh. The smaller the tank the more likely it is that you will get into trouble.

As dknguyen suggested getting a small table fan and blowing it over the top of the water will generate an evaporative cooling effect. It may only be a couple of degree but it is better then nothing. You could even build a trickle tower and force air up through water trickling through media. That would both cool and oxygenate the water.

To make that work you will need to take the cover off. By now I hope you have turned off any tank lights.

If you have fish that like to jump I suggest making some sort of surround that will let you blow the air and ensure that leaping fish end up back in the water. Maybe window screen.

Any decent filtration system will provide sufficient water movement.

If you are not aware of it the main danger of too warm water is that its ability to hold oxygen goes down quite fast. This means that as the temperature goes up the fish load that your tank will support goes down like a rock.

If you have any question I would be glad to try to answer them.
 
Why not air condition the room the aquarium is in, considering the price of room sized AC's and the price and design problems of making such a high powered peltier system it'd be cheaper and quicker to implement.
 
I want to create something for cooling aquarium water. What would you suggest I use then?

OK, sort of been there and done that. There was a time when my gun shop business was a part of a bait shop. Among the things sold was minnows from a large tank. I had nothing to do with the design but minnows need cool water and summer room temperatures of 75 to 80 degrees F. made for very unhappy minnows.

I would venture this tank had maybe 50 US gallons (maybe more). Cooling was done by using a drinking fountain chiller. Literally the guts of an old drinking fountain ran and ran as a chiller. The sides and bottom of the tank were insulated with an open top and aerator.

I will never forget the summer evening the power failed and I was the one who opened the door in the morning. The stench had me throw up things I never knew I ever ate. Yeah, minnows need cold water and a few thousand dead minnows let you know their presence real quick.

What you want is a small chiller. Forget peltier cooling. Find an old drinking fountain and gut it. :)

Ron
 
After rereading the thread I see you have rejected the fan idea.

If you are going to try to come up with any sort of chiller it will help to insulate the tank on as many sides as possible. You may be able to use a coil to exchange heat between the tank and a cube refrigerator. Check this page

If you have any pumps in the water switch them out for a hang on the back or a canister filter. For the most part all the energy used by a submerged pump ends up in the water.
 
cooler

I think I would try one first. You might be able to run one off the pc power supply you get the fan out of. In any case they don't like a lot of ripple. Put the biggest heatsink you can find on the hot side and a small heatsink in the water and see what effect you get. I don't know how big the tank is but you may be surprised. I used a couple about that size for a little air conditioner that blew on the back of your neck in the golf cart. Worked ok but was hard on the batteries.
 
Can't you run cold water from the tap through the tank via a pipe and exchange the heat via this simple heat-exchanger. Water is ony 15 cents per 1,000 litres.
 
Hi, Firstly I have done a LOT of research into aquarium cooling methods and have chosen this one for a reason.
The top is already off and the water has good movement on the surface. The surface area is on the small side, which I would largely blame the high temperatures on, my other tanks in the same room are much lower temperature (but have a larger surface area).
As mentioned I cant run the Air conditioning 24/7.

What I was hoping to do was create a similar device as: IceProbe Aquarium/Water Chiller by Coolworks

*Note this device doesn't seem to be available in the UK.

I already have the peltier plates shown in my first post, I dont really understand why it takes so much to run them. I can get them to work using a 9v battery, but they overheat (which I assume is because they are not getting the correct power).

The tap method mentioned is not practical as there is no tap on the floor the tanks are kept on.

*Note I am in the UK, mains electricity is 240v etc.
 
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my other tanks in the same room are much lower temperature (but have a larger surface area).

Could you use a heat exchanger between the problem tank and the other tanks?

All cooling devices can only pump heat from one place to another. All the electrical energy that you put into an air conditioning system, plus all the heat that it takes from the room, ends up in the outside part.

Also, most cooling devices are more efficient if the temperature difference is less. Often that is down to reducing the temperature of the hot part, by big heat sinks and huge fans. For example, a 5 kW aircon system will have nearly 1 square metre of radiator, with a big fan.

The same applies to Peltier cells, but they are less efficient, so more heat has to be got rid of. The aquarium cooler you linked to has a heatsink and fan on the hot side. If you have the modules on their own they will overheat very quickly at any power. You need a big heat sink and fan to keep them cold. They will pump about 50 W with the hot side at 25 deg C and the cold side 10 degrees colder. However, the input power is 80 - 90 W so you have to get rid of 130 - 140 W. If you let the hot side get up to 50 deg C, that increases the differential to the cold side to 35 deg C, and only 35 W of heat is pumped, and the input power increases slightly, so the same amount of power needs to be removed. That is obviously much easier if the hot side is 50 deg C, but you get less cooling.

Something like this Aqua Chill - Iceberg POU Water Cooler specifications cools 11.5 litres per hour while using 75 W. Now 11.5 L takes about 11.5 * 1000 * 4.2 * 20 = 966000 J to cool by 20 deg C. (The 20 deg C change is an estimate on my part). That is 270 W of cooling, while using 73 W. I think that shows why Peltier cell aren't used so much.

You still haven't said why that tank is hotter than the others. Is the pump a submerged one? If so, a radiator on the pump outlet to cool the water from that could be very effective.
 
Could you use a heat exchanger between the problem tank and the other tanks?

You still haven't said why that tank is hotter than the others. Is the pump a submerged one? If so, a radiator on the pump outlet to cool the water from that could be very effective.
No that wouldn't really be practical and I don't want to increase the temperature of the other tanks.

All my tanks have submerged pumps, the heat difference is caused by the difference in volume and surface area.
 
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