oBIX is an effort to provide an enterprise interface to building control systems based on the internet standards used in e-Business. Building control systems are all the embedded semi-intelligent systems in a building, whether in HVAC, Elevators, Access Control, Fume Hoods, Fire Alarms, Occupancy monitoring, Power Distribution, Utility Metering, Emergency Generators. . .
US Green Building Council (USGBC) standards are often closely related to the underlying control systems, whether they are goals of efficient energy use, healthful environment, on-site energy production, and, of course, commissioning. The best known of these standards are the Leadership in Energy & Environmental Design Standards (LEEDS)
The controls industry today poses its own problems. It is routine that the control system from one vendor does not interoperate with that of another vendor. When they do communicate, it is through protocols known only within the industry such as BACNet or LON or Niagra, or worse, a format specific to a single brand; operating information is not readily available to the owner or to the tenant. When a savvy operator does get access to this information, that information is extremely detailed at the micro-level and therefore hard-to-understand.
A key challenge for LEEDS is ways to facilitate and routinize commissioning. An acknowledged problem is ongoing measurement and validation of these systems, as evidenced by the poor ongoing energy posture of some facilities constructed to be Platinum. ASHRAE (American Society of Heating, Refrigeration, and Air Conditioning Engineers) has a proposed standard (189P) which looks to address some of these issues by defining (among other things) what information should be available from control systems.
The path to oBIX has a several steps. The first is a standard web-services based specification for communicate to the control systems at the concrete level that they operate. This function, which I shorthand as WS-Controls, is complete and allows for point access to each function and sensor within a control system.
The next step is to build some abstractions for each domain, i.e., family of systems, to make this data more useful. Control work is such detailed work, and relies so much on attention to that detail, that it is hard for someone not very immersed in the engineering to be able to understand what is going on. Abstractions will combine host of points into air handling systems, while hiding such details as “the actuator that fires immediately before the heating coil switches on to close the damper”. Abstractions will also allow the curious to request information about room temperature or humidity without plunging into the morass that is building tagging standards.
One of the abstract services we hope to provide is analytic information of the sort measured during commissioning. Ideally, the abstraction of an in-place control system control system would be able to plug right back in to the data structures created for pre-construction building performance analysis with analytical information that either is or is not in conformance the performance goals as designed.
This enables, in concept, the self-commissioning building. (I know, I still want field verification – but maybe the cost-effective statistical verification becomes more reasonable if we have 100% self-commissioning.) This then opens up the possibility of continuously commissioning systems providing ongoing instantaneous performance validation. Such a capability would substantially extend the reach concept of LEEDS for existing facilities.