Materials:

 1 old water fountain (this one was 1/5 hp)
 3 12"X12" pieces of 1/4" acrylic (for 2 sides and the bottom)
 2 12"X11.5" pieces of 1/4" acrylic (for the other 2 sides)
 1 13"X13" piece of 1/4" acrylic (for the top)
 4 1"X12" pieces of 1/4" acrylic (for tubing holders)
 2 12.5"X1/2" pieces of 1/4" acrylic (for 2 sides of the top lip)
 2 12"X1/2" pieces of 1/4" acrylic (for 2 sides of the top lip)
 70 feet of 3/8" ID vinyl tubing
 1 small stirring pump
 2 3/8" barb to 1/2" MPT adaptor, plastic, can be either straight, or an elbow.
 1 sheet of 1/2" styrofoam house insulation
 8 small clamps (to hold lid on)
 silicon sealant
 duct tape
 1/8" thick X 1/4" wide weather stripping
 "Weld-on" types 16 and 3
 1 gallon non-toxic antifreeze

1. Remove all of the panels from the water fountain.

2. Remove all of the plumbing from the fountain. Be very careful to not bend or break any of the coolant lines. You will be left with the frame of the water fountain and all of its major components (compressor, fan, condensor coil, thermostat control and cold water reservoir).

3. Unattach the cold water reservoir from the frame.

4. Remove the panels and insulation from around the cold water reservoir. This will be the part that makes the chiller work. It took a couple of hours to remove enough of the insulation to satisfy me. Be careful not to break any of the coolant pipes when removing the insulation.

5. Construct the cold water bath that holds the naked cold water reservoir. It is a 1 foot cube, made from the acrylic pieces listed above and held together with the "Weld-on". Be sure to test for water leaks before moving on. I was able to fit all 70 feet of the vinyl tubing into this cube. The longer the contact time in the cold water bath, the more efficient the chiller will be.

6. Glue 4 acrylic tubing guides to the inside bottom of the cube to help in coiling the tube inside the bath. These guides will keep the tubing in a neat coil. The guides are 12" tall.

7. Wrap the cold water reservoir with one end of the vinyl tubing (do not cut the tubing). Start wrapping about 6 feet from one end, to leave enough tubing to reach to the pump outside the box. Make sure not to crimp or twist the tubing. I used zip ties to attach the tubing to the chiller in strategic places. This was a rather tedious process, battling the natural tendancy of the tubing to twist. I used this end of the tubing to connect to the pump.

8. (optional) It is possible to make a base for the chiller out of scrap plywood. Mount the water fountain frame on one end of the base. On the other end, mount the acrylic cold water bath, leaving enough room for insulation on the outside of the bath. Do not actually attach the chiller parts to the base until after the next step.

9. Once you have figured out the relative orientation of the compressor and the cold water bath, you will need to make provisions for all of the coolant and water feed lines. Cut holes near the top of the side where the water feed and return are. The inlet and outlet tubes will slip through these holes. I used a 1/2" drill bit since the tubing was 1/2" OD. Also, cut small notches at the top of the side closest to the compressor. The coolant lines, and power cord for the stirring pump will run through the notches.

Note: I have a stirring pump connected to the water outlet tube of the reservoir. This not only keeps the water moving inside the bath but also gets the cold water out of the reservoir and into the bath, making it more efficient.

10. Wrap the cold water bath in the insulation, using silicone sealant to attach the insulation to the acrylic. Duct tape works well to keep the corners together. Cut holes in the insulation for the various hoses. I only went with one layer of insulation, but more is better if it will still fit on the base.

11. Once you are done with the modifications to the cold water bath, mount both the compressor and cold water bath on the base. The compressor was mounted by a couple of strategically placed screws. The water bath could be glued to the base but it isn't necessary. I chose instead to simply create a small frame for the bath to sit in so it would not slide around. I glued four pieces of wood onto the base in a square that is the size of the bottomw of the bath. The bath is not fastened directly to the base, which turned out to be helpful when wrapping the remainder of the tubing. At this time the reservoir and stirring pump should be inside the cold water bath box. Be careful not to crimp or break any of the coolant lines.

12. The remaining tubing (from step 7) was wrapped around the guides inside the cold water bath box. I found it easier to stretch out the tubing as straight as you can get it in order to make it easier to untwist and retwist as necessary. It does not matter which direction you wrap the tubing, as long as you do not get any kinks in it. I would push the tube down between the guide and the side of the box. when you got around to all of the coolant pipes I found it easier to lift the bath out of the base and slip the tubing underneath the box, while twisting or untwisting as necessary. This was significantly easier than trying to thread the rest of the 50 feet of tubing through the bath box. I kept wrapping until I had about a foot left. I then stuck this end through the outlet hole in the side of the box.

13. After all of the coiling is done, apply silicone around the tubing in all of the holes and notches in the bath box. This will keep evaporation to a minimum. The waterline inside the box is below all of the holes and notches.

14. Run the weather stripping around the top of the box where the top will fit. Also cover the top with a sheet of the house insulation.

15. Fill up the bath box with the non-toxic antifreeze and water. I cut a window in the insulation on the front of the cold water bath in order to see what the water line is in the bath box.

16. Connect the chiller to the tank. How you connect the chiller to your specific tank will depend upon your setup. This is the way I have it: The chiller gets the water from the refugium, and the chilled water is returned to the refugium. The pump is in line between the outlet of the refugium and the inlet to the chiller. The outlet from the chiller is directly connected back into the refugium.