cutting and pasting a long response I don't wish to retype, but I think this could answer a lot of yur questions about why a big chiller might make sense for you, and how to install it:
I have pretty limited experience with different brands of chiller. Basically only I've played with two approaches; a little chiller for every pot so to speak, and the big 2 Ton Chillking 'window mount' unit I got from a fellow farmer who was fed up with trying to make it work for him. This chiller draws 8.5amps at 240v, and it cools everything I've got while running less than half the time.
The way I made the system work is a bit involved, so bear with me;
Two things you gotta avoid at all costs; one is running dry cuz that'll kill your pump, and the other is loss of flow through a running chiller, cuz it will freeze and destroy itself. I got a 55 gallon drum reservoir, and placed my 1/2 hp Flotec pump underneath it so it would ALWAYS be primed. Side note; I had to buy nylon reinforced hose to run from res. to pump inlet, because the thing develops so much suction it was sucking weaker hoses flat- and killing flow. This also caused the pump to cavitate, which if allowed to continue will destroy the impellor.
The main 1" outlet from the pump goes to a splitter/reducer, then 3/4" lines go on to a couple custom manifolds I kitbashed from Pex brand 6 way copper manifold body and a half dozen 1/2" valves. I used a shitload of hose clamps and tubing to assemble all this. These become the 'inlet' manifolds, or the cold side.
From the inflow manifolds (one in each main room), I run 1/2" lines to 8" Ice Boxes with 8" maxfans blowing through them and hung from the ceiling. These fans are run by the environmental controller, and cool sealed growroom air very effectively. More 1/2" lines go to 15' copper coils in my RDWC (recirculating deep water culture) system, it's much like a UC. Water constantly flows over these coils and around the system, keeping roots nice n cool. I even built a circuit for a cooling coil that my aerocloner sits on, to help pull heat from its waterpump.
On the return side, I used more of the same 6 way manifolds and valves, so all the circuits go back to one of these manifolds. This are the 'outflow' manifolds, or the warm side. The valves are on both the inflow and outflow manifolds, so I can isolate any circuit I want and remove it for cleaning, replacing gear, moving stuff around, etc, without ever needing to shut the system itself down. I have a few extra spots on the manifolds to add more circuits to later, again, without needing to shut the pump and chiller down.
Return water flows from the manifolds through 3/4" lines directly to the 55 gallon reservoir. They do NOT get 'collected' with outflow from other manifolds, to keep return pressure lower than inflow pressure.
So where's the chiller fit in, you ask? On the faceplate of the flotec pump, there are a couple of nuts that you can screw fittings into. One of these feeds a 1/2" line that runs directly to the chiller and its return line also drops into the 55 gallon reservoir. This way the chiller always sees water directly from the pump so water starvation or slow flow issues are minimized.
The water running through the chiller system never interacts directly with water anywhere else. This allows you to run propylene glycol in 50% solution to improve performance even further, if you so desire. Do NOT run ethylene glycol because it's toxic and any leak into a hydro system would be disastrous. If you want to go this extra step (I didn't), I still recommend you run straight water until your whole system has been running for a few days- this will allow you to find and fix the inevitable leaks. The hardest leak to find is the one connecting your cooling coils in the hydro system- unless you lift the coil out of the water and inspect it, the only way you'll know it's leaking is when your system mysteriously overflows! Yeah, made that mistake too, lol.
Results? Shockingly good! Seriously. I don't have an issue with AC drying out my rooms, or having to constantly chase after the maintenance needs of a half dozen smaller cooling units. I run my water at about 60 degrees, this is just high enough to eliminate sweating on the manifolds and hoses or water spraying out of the Ice Boxes. For condensation/ dehumidification functions, water needs to be colder than this, Hydro Innovations runs inlet water for their air handlers at 45. Because of this, I chose to run a separate dehumidifier. 60 degrees also happens to be perfect for cooling an RDWC system, because I want that water to stay at 62-64. This way, I don't need to run any thermal switch on the cooling coils for them, it's constant flow.
Efficiency is also very good, as chillers, cooling dense water, tend to be about twice as efficient as AC. This goes double if your climate is arid and/or high altitude- AC needs mass in the air for it to work properly and if it's not there efficiency goes to hell fast- and in any case the cool won't carry further than the front of the unit. By contrast, cold water will cool anywhere you can run tubing to, even 50 or 100 feet away if necessary.
Okay, so it's a pain to set up. There is additional up front cost for hoses, manifolds, fittings, valves, pump, res., etc. You'll start making that investment back the minute you turn it on, and eventually the savings will pay for the whole thing by comparison to using AC. On the bright side, if you're running hydro, you're already used to dealing with circulating water, right?
If all this sounds like I'm a walking advertisement for water cooling, well, all I can say is that it proved that it's a better solution and thus made me a believer. Hell, I'm even gonna rig up another Icebox and Maxfan in my living room and use it to keep my tushie cool all summer!
