Building Automation: Big System On Campus
In fact, at college or on other multi-university campuses, you find quite a few distinct challenges. Some of these challenges include: How many contractors/manufacturers are appropriate? With more than one manufacturer, how is interoperability handled? Who installs/manages inter-building communications? What level of design standardization is needed? How do we support all this stuff? How do we deal with legacy systems?
How Many Suppliers/Manufacturers?Our first answer to this question is that one is too many and two is not enough. Seriously, there is no easy or correct answer to this question (and arguably the real question is, How do we get the best service and pricing?).
In an ideal world, one contractor/manufacturer would be the best approach given the issues of training, standardization, and ease of maintenance. However, purchasing rules may require that multiple contractors bid on each project, and the sheer volume of work may require the services of multiple contractors, anyway. Therefore, multiple BAS contractors and manufacturers are generally a given in a campus environment.
There are alternatives to this free-for-all, including a master agreement with a single manufacturer, using a manufacturer that allows multiple contractor representation within the region, or the use of open protocols and a unified user interface. Nevertheless, the challenge is in achieving BAS installation and operator-interface consistency so that facility operations can be optimized.
Interoperability Between Multiple ManufacturersDue to the above, many campuses find themselves with an installation composed of multiple systems. Fortunately, each building on a campus often has a single manufacturer’s system, so this challenge may be simplified to the choice between a single vs. multiple central operator interfaces. However, multiple interfaces make campus-wide optimization, data mining, and energy and operational analysis difficult, which is less than ideal. Therefore, a unified operator interface using open protocols becomes an approach worth investigating. However, the state of interoperability has not yet matured sufficiently to make this a trivial solution. Nevertheless, a properly applied open protocol solution with a uniform interface for operations, reporting, and analysis represents an option worth pursuing.
Inter-Building CommunicationsEthernet/IP communications has become the standard for upper-level BAS communications. The campus-wide (WAN) communications needs of a BAS can be simplified and less costly if the campus IT infrastructure is used. However, this usually requires inter-departmental coordination/approvals in areas such as communications security and maintenance, and it also includes system adds/moves/changes. One alternative approach is for the BAS WAN fiber to be installed and maintained by the IT department but dedicated for use by the BAS.
More subtle issues regarding the BAS WAN may become more obvious when an open protocol such as BACnet® is utilized. These include the proper management of network segments, broadcasts, and device/object naming and numbering. Such issues clearly require a campus-wide set of standards.