I was thinking the deposition rate would be high enough that the flow of tap water would suffice. The more important goal would seem to be getting the water to

I was thinking the deposition rate would be high enough that the flow of tap water would suffice. The more important goal would seem to be getting the water to a steady colder temperature so that it freezes consistently soon after it comes out. It would be nice to be able to augment the feed with snow too. Maybe an open tank, a circulation loop to the printing head, variable valve for the tap water inlet, and then perhaps a waterfall-based heat sink and/or a boiler loop depending if the whole setup still needs to lose or gain heat. I've also got to wonder if dribbling water would be the best type of print head, as opposed to say a pressurized nozzle that would make more of a fanned out spray.