Current best practice [and perhaps state regulations for public schools] require commissioning the controls. And RFQ's, RFP's, sealed bids, etc. The project requirements are discontinuous with a homeowner thermostat replacement in the same way that database cluster requirements are discontinuous with a Comcast residential gateway.
That seems orthogonal to centralization? Sure, an HVAC tech should regularly inspect each site, and should be on call for any issues. That doesn't require split-second coordination of mechanical operation among separate sites. We're talking about heating some schools, not operating a nuclear enrichment facility.
Neither is there anything about the "commissioning" process that mandates that control systems may only be replaced when mechanicals are also replaced. That would be ridiculous. Please note that I am not quibbling about the $2M cost. I merely observe that TFA discusses the control system only.
Commissioning etc. are orthogonal to the system configuration, and we should just agree to agree that a centralized control point is not necessarily necessary. OTOH IMPO, the control system requirements should be specified by a HVAC PE.
