The boiler system at Columbia Teachers’ College in New York City had been in need of an upgrade for a while, but the cost of new boilers created a challenge confronted by many facilities with tight budgets and aging boiler rooms. Faced with a system that had numerous problems, administrators had to find a solution they could afford. Would their limited budget scuttle their plans to improve the boiler system?
In the Spring 2021 issue of Today’s Boiler, David Bohn, president and CEO, Prefered Utilities Manufacturing Corp., spotlighted the energy-saving “linkageless” control system that was implemented at Yeshiva University in New York City, resulting in big savings through both energy rebates and overall reduced energy consumption. Now, we’re taking a look at a similar university application, but this time we’ll be focusing on the wide-ranging benefits of retrofitting.
Like Yeshiva University, Columbia Teacher’s College was dealing with an aging boiler system with numerous performance issues. The price of purchasing and installing new boilers remained an insurmountable challenge, and even installing new burners might involve a steeper price tag. In New York City, a new burner requires a permit, and pulling a permit requires a full inspection of the entire boiler room. This could trigger other unexpected and expensive upgrades to be required at the same time. The challenge: improve the system and make it safer and more energy efficient for a price that made sense.
The answer was a retrofit solution for their existing boilers that did not require a permit with the goal of improving performance enough so the college could earn rebates from its energy company. The operations team at the college decided the best solution would be a linkageless control system that would allow them to incorporate a variable frequency drive (VFD) and O2 trim, so they partnered with East Coast Mechanical, an experienced New York City-based mechanical contractor, to install the Burnermate Universal Control with a VFD for the forced draft fan, a solution that exceeded expectations in both price and functionality.
A VFD gives a pump or fan motor that usually runs at full speed the ability to modulate down to a lower speed. This reduction in speed drastically cuts down energy consumption.
A VFD was also installed to control the motors in the feedwater pumps. Like most boilers, this is a closed-loop system that produces steam, which condenses and then returns to the boiler in the form of water for reuse. The college was experiencing a number of problems with this feedwater system not handling load demands and causing waste and inefficiency, and this new VFD was selected to get the system back where it needed to be.
Similar to the solution-based strategy at Yeshiva University, this installation was designed to be linkageless. The old system only had the capability to control a single actuator, so one motor was attached to “links” between the different valves. As linkages wear out, the valves will not be controlled accurately. In the new control system, every single valve or air damper is independently controlled with its own actuator. This means boilers can be tuned with much more precision.
“This system provides a wide variety of benefits,” said Bohn. “The Burnermate Universal control provides both higher efficiency and improved monitoring and communication. Fuel savings come from parallel positioning of combustion control with provisions for oxygen trim and draft control, and electricity use is cut thanks to the ability to control a variable-speed drive for the forced draft fan.”
Though not specified on this job, the service provider won this project with its equipment, based on performance and ability to help Columbia get rebates from its energy company for energy savings and improvements.
But that’s not all that Columbia Teachers’ College was able to do in this installation. Administrators also took this opportunity to install a cloud-based monitoring system for maintenance, drastically improving staff’s control and ability to take preventive measures. The boiler room is, of course, not manned around the clock. In the past, if a problem, like a heating system failure, happened during off-hours, facility managers would not know about it unless it was reported — and, often, by the time the problem was reported, it had been an issue for hours. With cloud-based monitoring, administrators are able to select the personnel who will be alerted if a failure or other problem occurs, and those individuals will be notified instantly by text or email. The user-friendly system is easily configurable, allowing operators to prioritize the severity of problems that will trigger alerts. This kind of automated monitoring means their maintenance staff can often solve a problem before anyone even knows it has occurred.
In the end, the service provider completed a range of upgrades for the college as part of the retrofit. They installed a new plant master, feedwater center, cloud-based remote monitoring system, O2 trim (to monitor and self-correct emissions), and an e-link draft damper. The retrofits were completed for three boilers. It was a major improvement in boiler operations that fit the school’s budgetary requirements.
Thanks in large part to the energy savings created, the college earned a generous rebate. The energy provider offered a rebate program, proving they were improving their operations for maximum efficiency. Thanks to this retrofit project, the school now had the proof. The rebate they earned covered 70% of the total cost of the project.