I tried the following setup, and it was basically a waste of time. I used a mag 5 in my pump to run a 3/8 in line to my full size kitchen refrigerator. I drilled two holes in the back of the fridge and removed the bottom shelf. The 3/8 line was connected to about 4 coils of 3/8 line. When i bought these from home depot, i just left them as they came and connected them together using 3/8 quick fit connectors.
The coils were in a plastic container. Here is the part I tried that i thought might work, but didn't. The plastic container was filled with anti-freeze. I used a mag 1 (the little one) to push the anti-freeze over to the freezer side, through one coil, and then emptied back into the plastice resevoir.
RESULTS:
At times, the return water was a bit cooler. however, once the lights were on, the differential between the sump water was no more than a degree. What's worse, the refrigerator had trouble keeping things cool.
PARAMETERS: I have about a 275 gallon system. 95g dislplay with no MH, 39 gallon sump, 39 gallon resevoir, and the main display is 125g with 4 VHO's and 3 250 watt MH's. This is a lot of heat. Currently I use 2 1/4 hp chillers to keep it at 79degrees. At the time of my experiment with the fridge, i turned off one chiller.
Possible variations - I can think of a few that could obtain some different . FIrst, i used plastic line to run the anti-freeze. I think coppr would have been a better conduit. Also, i would have laced the copper return from the freezer around the 3/8 tank water coils.
Next, I was about 20 feet from the fridge. A closer run could have helped. Another variation would be the fridge - a stonger fridge might do better. I don't know if a deep freezer would work - but i suppose if the supply lines were not exposed to the air in the freezer, the anti freeze sump could be inside a cooler. Finally, a system with less water and less heat generation could make a difference.
CONCLUSION: Lots of variables, but unless your system is small, and the fridge is strong (and not loaded with too much or not opened too often), I cannot say this system would not work. I can say it did not work well for me.
