# Water temperature regulation

Hi all,

Hope you’re well!

I wish to monitor and regulate the temperature of a fixed volume tank of water that has a submersed pump within that is pumping water through a tube in a closed flow circuit.

The temperature would need to be kept at a steady 37 degrees c with a heating / cooling function if it gets lower or above. There would ideally also be some sort of manual override/ user display

I have a very very limited understanding of electronics and I would appreciate if anyone can point me in the right direction on how to do this.

I have searched and searched but I’m having no luck in figuring this out. I would really appreciate any pointers anyone could give!

If you don’t want to learn how to code, a fish tank heater will do just fine… and they are not very expensive (you might end up spending more for a custom solution that won’t look as integrated nor safe - high current and water don’t mix well).

Even if they pointed for you, you will not be able to understand what is written. Please correct the problem so you can get on with the project. If you are high school age or beyond, take some college electronics courses.
Paul

The amount of energy you need depends on the volume of water and the rate at which heat energy enters or leaves the water.

so your heater would need to be milliwatts (if a tiny insulated volume) - or megawatts if its a lake.

Also you would at least need to know about PID control

Yes …

How much water?
How accurate do you want to control it ?
What is the project doing - what does the controlled water do ?

I’m ok with coding, not proficient in it but I know enough to get whatever I need done! It wouldn’t cool the water though would it?

My apologies. I should have phrased this differently. What I meant by this was that I am by no means proficient in electronics, but I can understand circuit diagrams and build circuits etc with some guidance. I have tinkered with arduino before with basic projects but I am unable to find a solution to this particular problem through my own initiative.

In terms of specific volume, I’m not entirely sure just yet. The tank itself will be approx 20 x 30 x 20 cm with enough water to submerge the pump.

Accuracy within 1 degree

The project has no function per se it’s more of a demonstration of water flow through the pipe. It’s not actually going to be doing anything at all apart from circulating the water from the tank through the pump and through the pipe back into the tank.

Appreciate all your responses guys, I shall look into the PID controller John and see what I can come up with!

Would it be feasible for a cooling element for this? I can find plenty of things that show heating but not much really for cooling

Cooling might not be needed unless there is some heat source near your project. Switching on and off the heater should be sufficient to keep within 1 degree C.
No PID needed...

Heating and the cooling of the water can be done with heat exchangers and turning on the functions of the cooling or heating aspects of the heat exchangers.

How much water is the OP wanting to maintain temperature regulation of, what is to hot, and what is to cold?

What distances will the water be traveling through the heating and cooling pipes?

How fast do you want to temperature changes to manifest through what area of distance?

PID can be tricky, especially if you're trying to control heating and cooling in a single system. I suggest that you start the project with something simpler.

As far as I understand, the pump itself will generate heat which would heat up the water if it was left on for long enough

Pumping energy should be negligible, but it is a heat source indeed. What are the local conditions? If the surroundings go above 37 you might need cooling depending on heat loss via vaporization of water...

Let’s say approximately 10L of water; anything above 38 is too hot and anything below 35 is too cold

Everything will be contained within the tank with the tube above the tank to demonstrate the water flow. I’m not sure of the exact distance. I will get back to you once I have that all finalised.

Am I correct in understanding I will need two separate flow systems one for heated water and one for cold water? Is there no way this can be done with a single flow circuit?

Ideally within ten or so minutes or less? As fast as is simply possible

Could you please elaborate on ‘something simpler’?

What has temperature to do with "demonstrating water flow"?

Please explain. Even with a transparent tube, how will you know the water is moving? Will you have bubbles in it or what?
Paul

I'd start with turning the heater on if it's too cold and turn it off before it gets too hot. I wouldn't bother with cooling until you demonstrate to yourself that you need it.

Absolutely nothing; it is representative and only for modelling purposes

I am looking at 3D printing the tube with a certain refractive index, but I understand your point and I had not considered that at all