We tend to over integrate systems. In particular, we over-integrate building systems in high performance buildings. Because they all use similar signals, and have similar digital processing, the highest standard seems to be to integrate many systems as if they were a single system.
Each system should drive its own, and only its own, internal processes. Each system has a mission, a service it must perform for the enterprise that owns or inhabits the building. That mission drives the technologies chosen to compose the system.
The mission and the technologies drive the internal processes of each system. Because these processes are hard to do, and harder to do well, practitioners tend to think they are the most important part. Actually, no one cares, or should care, about the processes except from the inside.
Users and beneficiaries care only about the results of that process, what we call the service, and the requirements of that process, whether we call them inputs or call them costs.
The best way to integrate systems into a performant building is to ignore the processes, and to integrate the systems. The inputs must have clean interfaces so we can orchestrate the service provision. We must catalogue and understand the costs in resources and in waste. Thereafter, we should ignore the processes internal to each system during integration.
In business processes, bookkeeping is critical to any business. Accountants devise the processes for bookkeeping to make sure they accurately reflect the needs of the organization and that they produce accurate descriptions of business performance. Finance has to assume that the bookkeeping was done well, that the financial statements were well designed, and uses them to support higher level processes within the enterprise. Finance suffers if it focuses back on the Point of Sale.
Chris Martin, my friend who started his career in the Back Island microgrid, has recently examined the “energy financials” of systems in many research buildings. At UNC, we have central provision of steam and chilled water. Each building pulls its heating and cooling from the central distribution loops. It is an unfortunate truth that every building consumes heat in the form of steam, even in summer, and every building consumes cooling, in the form of chilled water, even in winter.
We have skilled staff who examine the energy-using systems in these buildings, and work hard to optimize them. This work is imbued with the deep processes of each system, and with the logic of the processes. Chris recently embarked on a different approach.
Chris began examining the “Energy Financials” of each building. As we work to break down silos between business processes, we are seeing for the first time, time sequenced data on energy use by each of the systems. In this analysis, the processes are hidden. All we have is the requirements and output from each system. The removes clutter and lets one see higher order interactions.
What Chris recognized is that the Chilled Water and the Steam consumption lay nicely on top of each other. For some months of the year, they could cancel each other out. During winter or summer, one fits entirely inside the other. This insight replaces fiendishly clever interactions with a simple one.
Chris is proposing a simple heat pump, or chiller, if you will, connecting the two systems. It will pump heat from whichever system is dominant for the season to the other one. It may enable some buildings to leave the steam distribution entirely. Payback on the small investment looks like it will range from 1.3 to 1.5 years, with a positive cash flow thereafter.
This is the advantage of hiding the processes, and looking only at the services and costs. The complexity of the problems you or someone else has already worked goes away. The opportunity for new solutions can be seen in the newer simplified set of facts. Chris Martin is demonstrating the advantage of approaching performance and efficiency of embedded building systems from the perspective of service oriented architecture.
Cool.