by Steven Horowitz, Optimum Energy
When you’re looking at ways to reduce your carbon footprint, options that usually come to mind include more efficient lighting systems, clean-vehicle fleets, and reducing waste and recycling.
However, there’s a big opportunity that is often overlooked or given a low priority: optimizing HVAC systems.
Chiller plants, boilers, and air handling units consume an enormous amount of energy. A small savings in chiller plant energy consumption alone may make a pretty good dent in your campus’s carbon footprint. It also saves energy costs and water. Campuses we’ve worked with typically see savings of 20 to 50 percent—that ROI adds up pretty quickly. And you’ll be certain your heating and cooling equipment is running at top efficiency. An added plus: the work often also helps with LEED certification.
Sounds good, doesn’t it? I know it sounds like a far bigger undertaking than installing new thermostats. Concerns among campus facilities operators include effects on critical environmental systems (such as labs) and adding unnecessary complexity to operations. Software-based HVAC optimization can be seamless, however. Because the solution essentially plugs into the building’s management system, there’s no down time and no disruption to operations, even for large and sensitive facilities. And because systems are automated, plants are actually less complex to manage.
Benefits accrue with both new and existing systems. If your HVAC system is slated for upgrading, that’s a great time to implement a software-based optimization solution. Your replacement systems not only will incorporate more efficient processes, they’ll also be able to use an optimization solution that continuously monitors the system and adjusts equipment operations to keep mechanical systems performing efficiently over time—no more performance drift. Plus, you now have all kinds of new data as well as accurate tracking of energy use and carbon savings.
Existing systems can typically be made much more efficient, and are excellent targets for optimization, even if they’re relatively new. For example, the University of Maryland Institute for Bioscience and Biotechnology Research (IBBR) optimized a five-year-old system in a building with inflexible climate requirements, converting to an all-variable flow plant and then adding an optimization and control layer. Depending on the time of year, the plant now runs 27 to 37 percent more efficiently.
Almost no human intervention is needed. An advanced optimization solution learns as it goes and adjusts systems automatically on the fly, so energy savings and efficient operations are not dependent on manual adjustments. To cite the IBBR example, our software collects a tremendous amount of data about the plant equipment, such as water flow, electrical power consumption, and load conditions. It then automatically changes pump and fan speeds, chilled water temperature set point, equipment staging and other operational changes to maximize efficiency. The software incorporates internal and external data to optimize HVAC operations, including weather, special environmental needs and hours of operation.
Disparate systems and many facilities? No problem. An optimization solution can bridge facilities, systems and teams, providing a holistic view of the larger efficiency picture. It unites large campuses because facilities staff at different plants now can all see the same data and know what is going on at all facilities.
Baylor University illustrates a common challenge: a system of mixed equipment. Its chiller plant comprises eight chillers of different sizes and ages, but our algorithms dynamically adjust valve positions so that the system is balanced under any combination of chillers and flow. The plant saved 5.26 million pounds of CO2 and 3.55 million kilowatt-hours within the first year of optimization.
Big campus? Start small. With a scalable, modular optimization solution that integrates with all building types and automation systems, you can start with one facility, and then scale across campus. At the University Texas Austin, one of the biggest campuses in the U.S., we optimized one of three chillers on a common loop, and then optimized the others. The project, which began with optimization of a brand-new 15,000-ton plant, is saving 21 million kWh per year.
There are advantages that go beyond energy savings too, such as improved operations and greater insight of systems data. But the fact is, HVAC systems can account for as much as half of the average building’s energy consumption. And in total, U.S. campuses spend about $14 billion a year on energy. With so much budget—and carbon—at stake, colleges and universities have nothing to lose by exploring HVAC optimization.