What Are The Best Practices Of Building Systems Integration?
Today, it seems like almost every day job can be accomplished by clicking a mouse or wiping a finger. This simplicity has led to some expectations that the new building automation system (BAS) would be able to provide the same features. With adequate upfront thinking and preparation, the unparalleled flexibility and effect of the device functionality can be achieved through incorporation and interoperability. Projects must be structured to consider how different structures can operate together and what is possible to have the functionality that both the customer and the owner want. However the customer and the owner must first be made aware of the opportunities to obtain additional features at little or no additional expense.
The phases of a successful integration
There are guidelines for interoperability (such as BACnet) but there are minimal guiding standards for building incorporation of best practices. It is always left to the control contractor or system integrator to provide their off-the-shelf solution. In this article, we will refer to control contractors that integrate multiple systems as “system integrators” due to the added expectations of integration. Many system integrators and control contractors have their own devices or controllers for similar applications. A traditional control contractor is not generally concerned with whether integration is effective or not, in the case of a system integrator. This is where it is important to consider what framework is being offered and what drawbacks which exist.
Owner and user requirements: The first steps in a good integration project are to gain a clear understanding of the objectives and specifications of the owner and the design team, and to consult the owner and the design team about what is feasible. Almost all of the equipment today comes standard with a BACnet, Modbus or LonWorks interface. Some owners have clear opinions and specific standards of incorporation, while others have only general criteria.
Routing data: Coordination with the Information Technology (IT) network is one of the most critical components of integration today. Designers responsible for integration must understand the capabilities of IT systems and have a strong working relationship with IT design engineers to manage the delivery of data from the edge or the end of the enterprise value chain. It is almost unlikely for an integration-focused engineer to have an extensive knowledge of all applicable data sources and volumes. For example, the fiber optic cable itself has many parameters that must be defined for each application. The IT engineer would know best how to determine fiber parameters, such as type of glass/transmission, strand count, construction (e.g., armored loose tube), rank, connectors, and type of termination.
Coordination: Working with a mechanical, electrical and pipe engineer is another important design activity required to achieve an interoperable integrated building. As a result of this initiative, systems are described by developing instrumented flow diagrams for mechanical and pipe systems. The instrumented flow diagram is a schematic representation of the system, such as the hot-water or AHU heating system which includes equipment, general pipe configuration, control valves, control dampers, instrumentation and input/output points, enabling individuals to quickly understand the configuration of the system.
Points List: If instrumented flow diagrams are made, a list of points should be established as soon as possible. The Points List is a table that defines each input and output point, both hardwired and via a network/communication link. This document can include warning values, analog scaling (if known), point function, and in some cases, explanation notes. Most of the network/communication links between the computer and the controller involve tens or even hundreds of input/output points. Many of these dots are not needed for control and data analysis. The list of points includes only the points that the designer thinks are important. The list of points should be shared with the owner and the design team so that the desired points can be identified. Additional points can be given to ensure that any points found to be required during commissioning and start-up can be applied. Too often, this is not discussed during the design phase, and the system integrator must decide which points to bring forward. Many times, they’re just going to map all the points that’s available so nothing’s missing. This ensures that all the points the user actually wants will be included, but also adds a significant number of unnecessary points, potentially hundreds. This is compounded if it is done for a number of devices. Electrical meters and variable frequency drives (VFDs) are good examples of this. Both have a large number of points and parameters available, and there are usually large numbers within the building.
Sequences: Mechanical and pipe engineers develop control sequences for their systems to describe how each system operates. Sequences typically focus on the functionality of the operation. The design engineer must understand how all systems within the building are designed to operate, as well as how they interact with other systems, so that integration can be leveraged. Typically, sequences need to be extended with a focus on integration to include items such as data storage, reporting, fault detection and diagnosis, alarm, scheduling, metering, lighting control, load shedding, shade control and security.
Specifications: While developing integration specifications, the design engineer should ask and understand why the systems are being integrated. Once the intended purpose of integration has been understood, the design engineer must determine what can be achieved. Is the goal of reading and storing data for trending and analysis only? Or is the objective also to include the control of the equipment via a communication link? This scope must be clearly specified and forwarded to the system integrator, as well as to equipment providers or other system providers.
Life Safety Integration: Many control contractors offer the ability to supply UL 864 controllers to integrate smoke control systems into the building automation system, eliminating the need for both the fire alarm system and the BAS to control smoke control equipment. When integrating smoke control equipment, all components of the smoke control system must be UL 864-listed. Careful consideration should be given to this prior to proceeding. It is recommended that the owner and the design team conduct a pros and cons assessment and discuss this with the local authority having jurisdiction before proceeding with integration. Advantages include reducing costs, saving space by sharing equipment, and increasing flexibility. Disadvantages include lack of contractor and user familiarity, additional operational testing, and upgrades to the BAS that may require the reset of the smoke-control system.
Construction: Construction is the most critical final phase of integration. This begins with the selection of system integrators to bid on the job. Integration work is very dependent on the skills and training of the staff implementing the solutions. Choosing a contractor with a proven history is crucial. Reviewing submissions to ensure that the protocols and features specified are provided is equally important, including those for packaged equipment, such as AHUs, refrigerators and boilers. If the equipment appears on-site without proper communication and configuration, delays may result and features may not be implemented.