I was excited to see this topic pop up since it makes sense to reject the heat into the water instead of the engine
room. I don't want to turn this into a HVAC
class... but I am learning
To paraphrase, if you cool down the refrigerant too much, you drop the pressure coming out of the condenser, which can make the expansion valve less effective. No pressure drop, no expansion, no cooling...
So even though high SEER condensers are all bigger, it is possible to go too big, and in this case with water being the heat transfer medium, very easy to go too "big". ie too much cooling.
The TXV valve will control the expansion and superheat. Is there a simple way of automating the condenser cooling if you are using a watercooled condenser?
I'm thinking of something like a thermostatic mixing valve or a version of a TXV valve with the power head
coupled to the condenser outlet...