Let’s face it: For many HVAC design engineers, building controls are an afterthought. Largely because so few engineers have hands-on experience with modern control systems, the design community as a whole tends to think controls are a much simpler component of the HVAC system than they really are. This is reflected in the generally poor quality of typical control-sequence documents and the disjointed process that continues to be employed to implement them. The result is that control contractors usually are left to develop their own concept of a system’s operating intent in relative isolation from the designer and the operations staff.
It is the failure of this poorly directed and convoluted implementation process that so often leads to operators turning off optimization strategies because they are ineffective, unreliable, and/or unstable. And it leads to the all-too-frequent declaration that a building has failed to achieve performance goals because of “control problems.”
While it is unlikely that real change will be made soon to the disjointed process of designing, installing, commissioning, and turning over building controls, there is emerging in the industry a new strategy for making controls—and the buildings they operate—much more successful. This new strategy starts with the truism that building optimization is primarily a building operations function. The corollary that the greater the support for building operations, the more effective optimization will be. So, rather than trying to imbed the sophistication of optimization into the disconnected process of designing and implementing building controls, optimization is seen in this new strategy as fundamentally an operations function that is correctly applied after the mechanical systems and building controls are complete.
But how does one apply this emerging strategy? It starts with HVAC system designers placing their focus on mapping out the fundamental optimization strategies desired to achieve the performance goals of the system very early in the design process. Then, their design process is aimed at developing a mechanical/control system design that will provide the equipment configuration and points of control and monitoring necessary to achieve the desired optimization. As part of, but separate from, this design path, the building owner or manager works with one of the emerging operations support (OS) firms to develop an operations plan. This operations plan goes well beyond traditional design team thinking on the subject. This discussion includes the issues of building operation staffing, cost optimization through negotiation, or use of special utility rate schedules, and the development of precise performance and energy cost targets that the OS firm will stand behind with ongoing performance verification and reporting.
The OS firm then coordinates this discussion with the designers to ensure the final design documents are compatible with the operations strategy that has been developed. The OS firm also often participates or oversees the commissioning and turnover phases as the owner’s agent.
To provide the support required to achieve the performance targets (and to verify to the owner that the targets are being achieved) the OS firm employs what each calls their “expert” processes. Some include data-mining techniques that sort though operating data collected from the building control system and fine tune or adjust control set points in some fashion based on what has been learned from past operation. Others employ advanced interactive control strategies that are adjusted based on real-time system operation and/or artificial intelligence principles. All incorporate some form of remote monitoring and control along with fault detection, direct operator support, and management reporting regarding actual building performance. These are called “cloud” services since they provide at least a portion of their support over the Internet, and the higher level “expert” analyses are accomplished remotely.
Emerging operations support (OS) services may offer a viable path to achieving the level of efficiency and cost reduction most know are possible but are almost never achieved and maintained with the processes through which control systems and building operations procedures are implemented today. Engaging in such a new strategy allows HVAC system designers to concentrate on those critical design features with which they are most experienced and more likely to control through the convoluted building construction process. It also permits building owners and operators to develop more effective and less costly approaches to building operations while achieving far higher and more reliable levels of building performance. It’s an emerging vision for a much more efficient and effective future for commercial buildings. This is a development that should be supported and encouraged.
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Thomas Hartman, PE, is principal of The Hartman Co., Georgetown, TX. He can be reached at 254/793-0120, or by e-mail at email@example.com.