On the campus of a major university, heat and hot-water steam-load demands can vary greatly in a short span of time. That certainly is the case on the 350-acre campus of the University of Arkansas in Fayetteville, Ark.
“Being in Northwest Arkansas, we have weather and temperatures that can vary widely,” Scott Turley, the university’s director of utility operations and maintenance, explained. “Also, being a university campus, we have high morning warm-up loads when students are getting up for class and taking showers, but that drops off pretty quickly throughout the day.”
To meet varying load demands, the university relied on aging large central-stationed boilers, but, as Turley said, that was “not the most efficient approach.”
To handle the on-demand steam requirements of the many buildings on its campus, the university installed six Miura LX-300 natural-gas-fired steam boilers.
“Miura’s modular, rapid-start, step-fired boilers ... can match our load profile much more closely,” Turley said. “... On-demand steam is a great asset for us. To be able to spool the boiler up very quickly and then take it back down offline when the load dies down is really helpful. Another advantage of the Miura boilers is that if by chance we lose a boiler for some reason, we only lose a sixth of our production capacity. If you lose a large packaged boiler, you can lose it all.”
Additionally, Turley said, “Through our performance contract with Johnson Controls, who installed the system, we added a centrifugal heat pump. Part of the heating on campus is now being done by this heat pump, and since the Miura boilers have the ability to start up very quickly and get up to load fast, they are a great complement to that technology.”
With the installation of the six boilers, the university not only has upgraded its physical plant with the advantages of on-demand steam and reduced its environmental footprint, it has saved money. Preliminary measurement and verification of project savings conducted by Johnson Controls reveals the university has saved approximately $280,000 since the boilers were installed.
Contributing to the energy-saving, green performance of the boilers is Miura’s use of precision computer technology. Each Miura boiler is equipped with a BL Micro Controller boiler control system that measures multiple individual monitoring points and provides operational status on pressure, temperature, and other factors on an easy-to-read digital display. A self-diagnostic feature can identify issues, while the Miura Online Maintenance feature that comes standard with every Miura boiler provides remote monitoring and control via the Internet. The system also can interface with Miura’s Colormetry system, which monitors water quality to prevent the buildup of scale inside of a boiler. (Users can opt to use Miura’s BOILERMATE water-treatment chemicals, the main ingredient of which is silicate, an environmentally friendly corrosion inhibitor.)