# My first build: peltier water cooler

#### FraterEx

Joined Aug 14, 2022
3
Hey all
I'm wanting to build a water cooler like the one in this video
However, I know absolutely nothing about electronics and have never done a project like this before. So I don't know if this will work as optimally as I hope and what kind of problems I might run into (hopefully none). Has anyone here built anything like this? Any advice?
My first task will be to gather the parts together that I need. I have an old water cooler in the garage I might take apart and see if there are any parts I can salvage

#### Dodgydave

Joined Jun 22, 2012
10,395
Peltiers are straight forward just two wires and supply the current required, these are used in caravan fridges. The main thing is a descent psu like an old atx from a PC

#### MrChips

Joined Oct 2, 2009
26,792
A thermoelectric cooler is a heat pump. It moves thermal energy from one side to the other side of the TEC. The efficiency of the TEC is a function of the temperature difference between the hot and cold side.
If the hot side gets too hot the TEC will be destroyed.

#### Irving

Joined Jan 30, 2016
2,991
Your first task is to say what you want to cool and why? What are the basic parameters: Heat flux (output) of source to be cooled (Watts), area to be cooled, temperature to achieve of heat source, ambient temperature, are a good starting point. Peltiers cant do magic, sometimes the energy you need to put in significantly exceeds the benefits you can achieve.

#### FraterEx

Joined Aug 14, 2022
3
This is for a project where I need a constant flow of cold water running through a lab condenser for a long period of time (using the tap is not an option). So I decided to just go simple. I popped off the support collar for the water jug to get to the reservoir and stuck a small fountain pump in there. Now I have a tube going from from the pump to the intake of the condenser and a tube leading from the outflow back into the reservoir. The only thing I think I need now is to make a lid using xps foam to cover the reservoir with holes for the power cord and tubing. That way the water in the reservoir is better insulated.
So I think I just solved the problem without having to build anything. But if anyone here thinks that I can make something more efficient, then I would love to hear about it. I'm happy to spend some cash and effort into building something if I can save money on my electrical bill in the long run.
Thanks!

#### bassbindevil

Joined Jan 23, 2014
505
A conventional refrigerator with a compressor will be more efficient and will be effective regardless of room temperature. I've paid as little as $7 for a used mini-fridge, but new they're only about$100. It pulled about 85 watts when running, compared with 48 watts for a Peltier camping cooler. The overall energy consumption would be far less, though, since the fridge only cycles periodically, and it also was able to maintain near-freezing temperatures even with room temperatures in the 30C range. The Peltier cooler will only manage about 20C of cooling with respect to ambient, and takes a long time to move enough heat to chill a 6-pack.

You could calculate the heat being collected by the condenser, by measuring the flow rate and temperature difference between incoming and outgoing water. Then you could determine if Peltier cooling is even feasible.

#### Irving

Joined Jan 30, 2016
2,991
This is for a project where I need a constant flow of cold water running through a lab condenser for a long period of time (using the tap is not an option). So I decided to just go simple. I popped off the support collar for the water jug to get to the reservoir and stuck a small fountain pump in there. Now I have a tube going from from the pump to the intake of the condenser and a tube leading from the outflow back into the reservoir. The only thing I think I need now is to make a lid using xps foam to cover the reservoir with holes for the power cord and tubing. That way the water in the reservoir is better insulated.
So I think I just solved the problem without having to build anything. But if anyone here thinks that I can make something more efficient, then I would love to hear about it. I'm happy to spend some cash and effort into building something if I can save money on my electrical bill in the long run.
Thanks!
I don't see how that works over "a long time". The water exits the condenser at a higher temperature than it enters. It passes to the reservoir which is a larger body of initially cooler water so the two mix and the water returning is cooled but the reservoir is warmed up slightly. The exact ratio depends on flow rate and reservoir volume, but over time the reservoir will warm up (especially if well insulated) unless the water jug has active cooling itself but there's nothing in your description to suggest that.

#### FraterEx

Joined Aug 14, 2022
3
I guess I should have been more clear. The water cooler dispenser is the kind that plugs in and refrigerates the water. So the water in the reservoir will always be kept cold. It's the efficiency I'm not so sure about. But if I understand Bassbindevil right, then that's nothing to worry about

#### Irving

Joined Jan 30, 2016
2,991
Ah, that makes more sense now. As long as the cooler 's ability to cool exceeds the condenser's ability to heat, all will be well.