Here's where I stand, I've custom built a PC with a water cooling system and I want to take it a step further by actively dropping the water temp below ambient for 24/7 operation with the ability of chilling the water (water/glycol or alcohol/glycol) below 0c. I love DIY projects and this is more for fun than practicality, my system currently stays under 50c during full load which is well within limits (70c is the CPU's limit). I already have a compressor from a 22 cubic ft deep freeze running r-22 and a condenser from a GE HotPoint. I'm currently working on the evaporator coils, I'm using two double helix coils made of 1/4" OD ACR copper tubing in two separate reservoirs. For the expansion valve, I'm wanting to use a thermostatic expansion valve. This is one area I need help with is choosing the expansion valve to use and the size of the orifice. I also need help in figuring out how much oil and refrigerant (R-134a, unless there's a better replacement for R-22) and what pressure the system should run at.

I've done some research online and on forum boards but can't find much on specifics, I understand the general operation of phase change systems, how they are put together, and copper brazing. I just need a little help hammering out the specifics. Any links to existing threads that could help on this or other forums would be welcome and any suggestions/criticism (be gentle, I'm a noob, lol) are also welcome.

Thanks in adavance.