I know this could seem to be an insane idea, but together with some friends we're talking on building a big brewing system, where big could be a batch size among 250 and 300 US gallons.
[my build experience]
Reading and browsing here around I was able to build from scratch my HERMS system, with three 26 US gallons kettles and I'm quite happy with the results . Not fully completed, actually I'm using it in an hybrid way, manual/motorized. Well enough to obtain good batches. It will be powered by the brewtroller, already in charge to manage the relays.
First of all I think that a 4 kettle should be better, with a small kettle devoted only to the HERMS reciclyng coil (with an electric heater inside, regulated by a PID). But is HERMS a right way to go with that batch volume? Or should it be better with a RIMS tube? For sure I'd have to scale up the hoses, valves and pumps to at least 1" (currently 1/2" in my build). Or there is out there in pro builds a better approach to follow? I know an easy way could be to buy an used system, but more than half of the fun would be to build it together from the scratch. This will be OUR system!
Any hints or suggestion?