February 2011


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Toby Considine

EMAIL INTERVIEW - Toby Considine & Ken Sinclair

Toby Considine, TC9 Inc
The New Daedalus
Contributing Editor

At a recent oBIX meeting, we discussed higher levels of abstraction in interacting with building systems. We discussed services in terms of enterprise interactions, and agile development and hiding complexity. Now that WS-Calendar is nearly done, we have the opportunity to coordinate building services with enterprise activities. We can imagine a WS-Calendar server in the home thermostat, able to interact with personal schedules stored on the Blackberry, iPhone, and Android. We can imagine it informed by the energy market signals, and the school calendar, and the little league (See Elm City, http://blog.jonudell.net/elmcity-project-faq/, and supercharge it with services and energy prices). We decided it did not belong in the core oBIX services, but we wanted to see it done.

After the ASHRAE meetings, and during the AHR conference, some of us are meeting (11:30, Tuesday, February 1, Room 107) to discuss building system metadata. The goal is to define interfaces to support quick fast integrations of building systems into the wider world.

The Building System Interface

Space is what the building systems support, space is what the tenants recognize, space is where building systems deliver service. To interact with those services, we need building services interfaces (BSI).

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Sinclair:  Toby, what is the Building System Interface?

Considine:  In my smart grid work, I began describing each end node as a microgrid. A microgrid is a self-contained entity responsible for managing its own energy use, generation, storage, conversion, and as a last resort, market operations. This model eliminates direct grid control of buildings. Maximum grid incentives, all delivered to a single energy services interface (ESI), the locus of market bidding for the building.

The ESI is the external face of the participants in smart energy. The ESI facilitates the communications among the entities that produce and distribute electricity and the entities that manage the consumption of electricity. An ESI may be in front of one system or several, one building or several, or even in front of a microgrid. In keeping with service oriented architecture (SOA) principles, there is no direct interaction across the ESI.

Today, an ESI is most often on the outside of a building system. The leaders in commercial energy management, companies like Target, put the business between the ESI and the building systems. Target evaluates energy use, and changes in energy use, as normal business decisions, and building systems respond to business operations. Target though, is unusually aware of its decision processes, has many nearly identical buildings, and has strict commissioning standards. For the rest of us to be like Target, we need a Building Systems Interface (BSI).

The BSI must expose several services. New systems will certainly incorporate the market-oriented interfaces of smart energy, for use inside the building microgrid. Other services will interact with the business, linking corporate calendars to building operations. Another will request and consume weather information; a data center should take advantage of a cold winter such as this to limit cooling loads.

Systems must tie their information to the space that the enterprise inhabits. It is not enough for points to self-describe themselves as an air handler—that air handler must describe itself in terms of the service it provides to a particular space. Space is what the building systems support, space is what the tenants recognize, space is where building systems deliver service. To interact with those services, we need building services interfaces (BSI).

There will be enterprise-based applications that link between the occupants and their activities and the BAS and its performance. These applications simplify and abstract business activities and schedules, using the common schedule communications developed for smart grids. They will be aware of the market conditions and deals made with the grid though the ESI. They will know whether the volatile energy of the renewables-based grid is scarce or abundant. They will understand the distributed energy resources of the building. They will report back to the enterprise how and where energy is being used right now.

It won’t be good enough for these applications to interact only with the major building systems, only with HVAC and Lights. These applications will want interfaces even to the live-load, or plug-load. Even the live load must be able to report its energy use, described in relation to space. Panel sub-metering and BIM-based circuit tracing (PLie – panel layout information exchange) put even the coffee pot and copier as part of the BIM model for energy use. Even home appliances must be participants.

These applications will talk to the BSIs for each system. They will not be based on single brands, or on proprietary technologies. They will not require deep integration with the systems they influence. These applications will be built in the gap between the ESI, the Enterprise, and the BSIs.

Sinclair:  Please explain BIM, Cloud Services, and Discovery.

Considine:  To be enterprise ready, the BSI must support Discovery. We must be able to discover building systems, virtual meters for plug-load, and appliances using WS-Device Discovery. Common system metadata, the same that describes a collection of points as an air handler, must be packaged into WS-Device Profiles. Each device must expose both a system profile and an energy use profile. These standard interfaces will be the new commissioning standard.

Because system metadata and profiles create business objects, this work creates the rational basis for policy-based security as applied to building systems. It is meaningless to ask if a system is secure unless you define what security means to you. Are you looking for a locked door, or are you looking for business enablement? (http://www.newdaedalus.com/articles/bouncer-or-prison-guard.html). System profiles bring building systems into normal security.

So what are the essential building services? There is energy management, accessible for low integration re-hosting in the clouds. There is performance contracting, also in the clouds. There is energy auditing, which only exists as a business based on near-zero integration costs (because the metadata is already in the BSI). Energy auditing? Well what if we call it a live LEED rating, or perhaps 3rd party verification of the performance of the performance contractors. BIFER (BI for emergency responders) may even come from these standard interfaces.

And, of course, WS-Calendar will inform the enterprise and consumer interactions. As energy grows more expensive, and its supply less predictable, doing the right things only at the right times becomes more valuable. The corporate calendar, the smart cell phone, and the school schedule will talk directly to buildings through standards-based service interactions.

Modern service interactions are based on composable interfaces and open specifications. Composable interfaces tend to be small, and to solve a single purpose. They free the developer and the system integrator to create novel interactions, and new value, quickly. We can see what some of them are already.

They will start with commissioning. COBie (Common Operations Building information exchange) defines a family of information models that can be handed over from a construction Building Information Model (BIM). These include a catalogue of building systems and the spaces they support. A newly proposed aspect of COBie is Panel Layout information exchange (PLie) which ties electrical circuits to the spaces they support. If we can solve the metadata problem, we open the door to a large competitive market place for software that engages customers in smart energy while improving the service delivered by smart buildings.

[an error occurred while processing this directive]Sinclair:  Explain the Metadata Problem for us.

Considine: Metadata refers to information about data. While control systems for buildings today can offer up an impressive amount of data, it takes far too much effort to figure out what it means. In a medium-sized commercial building, tens of thousands of points can take a month to unravel before useful integration with the businesses and lives of the people who occupy those buildings is possible. Throughout all the integrator must understand the technologies in use in that building. At the end, the integrator produces proprietary results himself.

Most of that integration effort is in deciphering what those information points mean. Is that point an internal point, useful only to the HVAC professional, or does it represent a room temperature, or oxygen level, of interest to the building occupants. Do these points describe one air handler or ten? Does one compressor support many air handlers? What space, which means what business services, does each system support? Today, only the trained professional can discern the answers to these questions, with the blueprints in one hand, and years of experience in the other. Through the BSIs, and through the BIM, they will be discernable by machine inspection.

We need a relatively few profiles to pull this off. Or maybe we just need some rules about profiles, and a place to create a repository. Too many profiles would just recreate the chaos we have now, in which metadata is all free-form tags.

There are several existing profiles for communicating with energy meters; we need to get to one. The profile model should be able to indicate what systems are behind it, by reference, to the discoverable catalogue of building systems and spaces. Whether you call it live load, or plug load, circuits and the space they support can be described in PLie. Everything, of course, should be tied down to the space or spaces it supports.

BIM standards contain standard descriptions for how a space is used. The links to space, offer potential keys into business directories and business schedules.

The place to start collecting this metadata is during commissioning. COBie (Common Operations Building information exchange) defines a family of information models that can be handed over from a construction Building Information Model (BIM). These include a catalogue of building systems and the spaces they support. As retro-commissioning starts to follow commissioning standards, we would begin to get the benefits of the BSI-enabling metadata in existing buildings.


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