Question about corrosion
 

Are phase change units susceptible to galvanic corrosion in the same way that water cooling loops are, for example, if a silver evaporator was used with a copper condenser, or is the presence of water required.

8-ball

Wouldn't that depend on the electrical conductivity of the coolant?

I'd say: "probably".

I guess it would.

Mind you, I guess it's less important with phase change.

With watercooling, we have reached a point where moving from copper to silver can gain a few valuable degrees, but with phase change, gaining a couple of degrees, when you're already running well below ambient are less important.

Copper should suffice.

8-ball

Not a big problem...all compressor casings are steel and the discharge lines also are somtimes steel. The only time you see the steel rust is when it is exposed to water as in outdoor conditions.....even if rust is present on the exterior you never see any corosion inside.

Corrosion is a big problem but only for improperly charged systems. And, it isn't galvanic corrosion, it's straight rust and acid etching. If water vapour gets in, it can cause chemical reactions that create bad things such as hydrofloric acid (not that water in and of itself isn't bad for steel and the motor wiring in the compressor). That's the paranoid answer.

The real answer is, "No". Use a vacuum pump to get all the water out, use clean refrigerant, and it should be just fine. If you start using things like ammonia (for an adsorption system, for example), things can be more exciting. But, if you are doing things like that, I'd assume that you know to use stainless steel tubing for corrosion resistance and high pressure strength.