I'll be honest...i do not have much experience at all with water chillers. And water cooled conditioning. I know mini splits like the back of my hand though. The whole concept behind cold water for grow rooms kinda turned me off before i even gave it a chance. Stuck in my ways i guess. If anyone out there can enlighten me....feel free.
Me. Water is an ideal heat transfer fluid because it's very dense, can't be heated with compression, and it's basically free.
Running all the water lines is a chore- once- but the advantages make it well worthwhile. You can use one chiller to cool multiple systems, even several spaces. If you run two bloomrooms on a flip schedule, the unit will cool them both automatically, saving the need to buy additional capacity.
If you like RDWC, you need water chilling to keep the roots cool. The same water cooling system can supply a cooling coil wherever you need one.
Water cooled air handlers combine room air cooling with dehumidification in one unit that isn't constantly fighting with itself. This saves a shocking amount of power compared to the standard practice of running a compressor based dehumidification unit against an AC unit! And, it delivers more fresh condensate water every day than I can use!
If the homeowner or facility designer chooses a heat pump, then the savings opportunities multiply; all that rejected 'waste' heat can now be recycled for building heat, warming heat in growrooms, domestic hot water heating... I'm even going to try to heat my hot tub!
To recap, water based HVAC isn't for temporary installations, but it saves money by moving heat efficiently from places it's unwanted to places it's welcome. The larger the scale, the better it works and frankly, the less practical other approaches become.