Dont buy a chiller ... use a heat exchenger

[RuGlu6]

With temperatures are as high as 30C today my tank temp jumped from 24C up to 26.5C.
So i thought its a good time to put my DIY heat exchanger to use again.

All it is , is a plastic tubing line from Home Depot "T-ed" of off cold water RODI supply tap water inside plastic tubing line going from the "T" to my reef tank sump. Then its coiled up in a small coil (about 25 feet of tubing) that plastic tubing coil is submerged it in the sump water. The plastic tubing line then continues from the sump coil back to under the sink and to the drain.


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heat exchanger coil, i have another "vessel" inside the sump then water overflows down to the sump.


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flow control valve. Sorry, the picture is sideways. You can also see yellow line going back to the "P-Trap" drain.

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I am using RODI "waste" water line to discharge heat exchanger water to the sink drain. If you dont have RODI you can go straight to the "P-Trap"

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So the cooling is achieved by heat being transferred from sump warmer water to colder water inside the heat exchanger coil.

Tap water is about 12C tank water is 26C (now down to 24) This trick works and there is enough heat transfer with that temp. difference to keep 65 Gal + 20 gal sump at constant 24C.
I even have to have a heater on and to slow down the water flow inside heat exchanger plastic tubing coil down to the steady slow drip to prevent from cooling too much.

If you have a large tank, double or triple the coil size or get Stainless Steel coil to get enough cooling capacity.

Not sure about prices today but few years ago Home Depot was selling plastic tubing in 25 feet increments for about $6. The whole project cost was less then $60.
This obviously will depend on how close your tank is to the sink.
When its really hot outside the line going from the cold water tap will sweat a little.

It took 25 min for me to type this, and my my tank temp went down from 26.5C to 25.5C.
This DIY heat exchanger works !

Pros:
cheep to make (providing you tank is close to the sink)
Easy to operate and with any heater in the sump it is somewhat automated and protected from over-cooling.
Way more cost efficient than buying a chiller
No electricity involved when house power is out it will still work.

Cons:
Wasting water.
Slight condensation on the tubing
Tripping hazard if tubing running across the room (mine is going along the walls, hot glued to the floor moldings so not an issue)
Will not work if you tank is far away from the sink.

Hope some one will benefit from this