Use as little anti-freeze as possible.. It sucks at heat transfer.. Atleast Glycol based AF is..
Anyway... go on the back of the bottle.. it gives a chart.. I think it's like.. -20F 40% AF 60% water.. -60F .. etc
So if your water stays around 20F.. I would say start out with 10% AF and 90% water..
It doesn't matter if you have a bit of frost on the top of the water.. You just don't slush.. or ice in the water lines.. As long as you have a strongest enough pump though you shouldn't get ice in the lines no matter what.. as long as the water is flowing that is..
You aren't running these real great temps.. Don't get me wrong though.. You are cooling your compressor with that water too.. which just amazing that you are still get such low temps.. But let me tell you that the compressor NEEDS to get warm/hot.. Because it is compressing the freon from a liquid to a gas.. (or is it gas to liquid?)
Either way .. it needs to compress the freon.. The compression is energy used which comes off in the form of heat.. so that the freon can turn into gas from a liquid and go into the condensor to get cooled.. I suppose if you super chilled your compressor.. you in theory wouldn't even need a condensor.. cuz that's all the condensor does.. is remove the heat from the refrigerant because of the compressing process.
Oh, BTW.. Bowman is using a 1/4HP? (i think) compressor.. it's R22 which has a LOT lower boiling point then R-134A.. which is whats in your dehumidifer most likely.. same with my phase change setup.. Doesn't mean our systems can't be good too.. we just won't see -57F
Bowman, I am running this setup,
30Ft Evaporator.. divided up into 3 coils 10ft each.. in 3" PVC pipes that have water flowing through them at 1/2" connections with a 360GPH pump...
20Ft condensor.. Divided up into 2 coils 10ft each.. in 3" PVC pipes that have water flowing through them at 3/8" connections accept for on the last pipe the exit barb is 1/4" (to keep up back pressure so the tubes stay 100% full at all times) with a 120GPH pump.
Do you see any advantage to me water cooling my condensor..? What do you think about that setup? It's a 1/20HP compressor. R-134A.
Oh and do you think my 360GPH pump will be good enough to keep water pressure up in the evaporator tubes so the entire evaporator coil is covered in water? What do you think about that water chiller idea? Should I have the exit on the last evaporator pipe be 3/8" or something to keep up back pressure? I am running a 1/2" water block n all ..
Adios