In today’s difficult economic climate, when financial savings are critical to every healthcare institution, facility managers demand even more from energy systems while looking to spend less. One way to achieve significant energy savings without making a substantial capital investment is through energy monitoring and chiller plant optimization.
The greatest energy savings available can be generated from a facility’s existing chiller plant operation, where even small tweaks can result in significant improvements. Today’s web-based monitoring systems can be an effective tool for the analysis of large chiller plants and district cooling systems. Built on open standards, they offer networked solutions that collect and format data in real time and defined timeframe increments, monitor operations and equipment errors and deliver oversight via web-based alerts and alarms. Based on the information generated, engineers are able to track performance and remedy any malfunction in order to optimize energy efficiencies.
The monitoring process starts with an initial analysis of chiller plant operations. In most cases, industrial measurement devices are installed and existing equipment tested for accuracy. The data from the various systems is pulled together in one platform and routed to an automation system, then pushed to the web every five minutes via ftp; most automation systems that are web-based have the ability to do this very easily. Once the accurate data collection is completed, an evaluation is done to understand how all the chiller components are working and determine the most efficient method of operating the plant.
By analyzing chiller operations, the monitoring engineers are able to establish a matrix that selects the most efficient and cost-effective chiller configuration as a facility’s cooling load increases. Optimization steps might include redoing the sequencing of cooling towers, balancing the amount of energy consumed by different pieces of equipment and allowing chilled water to be generated at the best efficiency and lowest cost. Other cost-saving measures can be implemented by calibrating temperature sensors and the building automation system, eliminating inefficiencies in heat exchanger performance, lowering condenser temperatures and ensuring that flow through the plant and chillers meets the design tonnages recommended by the equipment manufacturers.
Once the initial reconfigurations have been achieved, the web interface enables continuous remote monitoring of a plant to ensure optimum operation is maintained. Monthly reports are submitted to the operating team to show actual savings from the enhanced operating strategies and to suggest additional system improvements.
Monitoring-based commissioning
With new hospital facilities, generating ongoing energy savings can be achieved through a comprehensive monitoring-based commissioning, or MBCx, process to ensure all building systems remain “in tune.” It is common knowledge that buildings rarely perform as intended. That’s why MBCx is beginning to emerge as an important new approach to keep buildings operating at maximum energy efficiency. Complementing other energy savings strategies, it refers to the “soft” process of verifying performance and design intent and correcting deficiencies through a continuous web-based monitoring program.
MBCx incorporates three components:
> Permanent energy information systems and diagnostic tools at the whole-building and sub-system level
> Retro-commissioning based on the data this generates
> Ongoing commissioning that ensures efficient building operations and measurement-based savings
Traditional commissioning is a process designed to ensure all building systems perform interactively according to the design intent and the facility’s operational needs. It involves the participation of an owner’s representative, architect and engineer of record, as well as independent third-party commissioning specialist. The commissioning specialist works with the entire project team to verify that design, construction and startup of all equipment results in a facility that is achieving the owner’s stated project requirements upon initial occupancy.
Here’s where monitoring-based commissioning takes over. Even the most technologically sophisticated facilities will experience equipment variables that result in diminished energy efficiency. The reasons why buildings typically do not perform as planned might include poor control of chilled water distribution to air handlers, badly sequenced chiller operation or poor VAV zone control. The ability to verify performance and design intent on a regular basis, and immediately correct inefficiencies, presents an effective way of keeping a building’s long-term energy use on track. This is especially significant in a campus setting, where utilities are system-critical and different buildings run on multiple power sources with chiller plants that need to be integrated effectively.
Taking holistic view of energy performance
This was the case with a recent program of continuous energy oversight for the chiller, boiler and cogeneration plants at the Newark, New Jersey campus of Rutgers Biomedical and Health Sciences, which has resulted in $1,155,000 in savings in its first two years of operation. The RBHS facility is a district energy plant that provides utilities to six buildings at RBHS, including University Hospital of Newark, comprising a total of 2.2 million square feet of research, academic and healthcare facilities.
The plant and outlying buildings had been retrofitted with new energy-efficient equipment to provide the energy plants with the equipment and redundancy needed to help assure reliability for the next 10 years. As part of the capital improvement project, a central plant monitoring system at the facility was designed and implemented by utiliVisor. The system monitors 824 data points, including all operations equipment at the plants. A program of continuous energy oversight was implemented for the 20,700 ton chilled water plant, 291,000-pounds-per-hour boiler plant and 10.5 megawatt cogeneration system, along with all ancillary equipment.
The monitoring program involved continuously commissioning energy plant operations to maximize the payback of the retrofit to the university. The effort took a holistic view of energy performance, analyzing the operation of each piece of equipment required to generate and distribute chilled water, high-temperature hot water and electric power to the campus.
The web-based, networked energy oversight system works in real time to collect and format data from the new chiller plant components. The data is used to compare actual chiller plant operations against design-efficiency benchmarks and identify equipment errors, communicating alerts by email to energy plant operators and facility managers. Steps to improve performance are recommended and the cost savings are calculated. The chiller plant monitoring and analysis tools are also available to plant operations and facility management staff over a secure website, which is accessible from any location using a desktop PC or mobile device.
The utiliVisor engineers are responsible for analyzing real-time energy data from the facility and recommending the most efficient operating strategy at all-load conditions as the conditions change. The data analysis enables the equipment to be fully optimized on an ongoing basis, resulting in substantial energy and cost savings.
A recent study prepared for the California Energy Commission by Lawrence Berkeley National Laboratory stated: “On a portfolio basis we find MBCx to be a highly cost-effective means of obtaining significant portfolio/program-level energy savings across a variety of building types. MBCx helped identify a very wide range of deficiencies. Anecdotal evidence shows the value of monitoring in identifying savings opportunities that would not otherwise have been identified.”
Remote energy monitoring offers a cost-effective means for healthcare organizations to realize greater energy efficiencies and lower operating costs over the lifecycle of a building. Monitoring offers an important risk-management strategy that leads to verifiable and durable energy-demand reductions.
