John,
You can save a LOT of money by doing a geothermal ground loop chiller. It's about the same upfront cost as a good chiller (a little cheaper actually), but operating cost are reduced exponentially.
It's fairly simple...you will need:
1/4" -1/2" "flexible coiled" copper pipe. Comes in boxes in 25', 50' and 100' coils (diameter will depend on how large your system is).
PVC pipe
copper sweat -
PVC couplings
a chiller barrel (aquatic-eco has some nice thermostatically controlled ones)
Lots of aluminum shavings
Dry concrete mix
a large auger to drill a hole (8" - 12")
PM me if you are interested in doing this, and I'll explain it better on the phone...but here's the short and sweet of it:
Drill a hole deeper than the frost line (below the water table if it's not to deep)
Loosen up the coiled copper some so there is some space in the coil, connect
PVC to it so that the coil is at the bottom of the hole and the
PVC is running to the chiller barrel in the GH.
With the coil in the bottom of the hole, dump in a couple of garbage bags of aluminum shavings in the hole, followed by the dry concrete. The aluminum/concrete mix increases the ability of the fluid in the coil to "get cooled"
Back fill the hole.
Inside the GH, you will connect the
PVC coming from the hole to the refrigerant lines of the chiller barrel, and the system to the barrel.
when the system calls for cooling, fluid will cycle through the chiller barrel, picking up heat and transferring it to the ground through the coil/aluminum/concrete heat sink.
You are creating a "closed loop" system, so you should use glycerin or some other non freezing fluid in the cooling loop so that it doesn't need drained and flushed every winter.
The aluminum/blue combo has proven to be a huge money saver in operating costs...in both summer and winter
