Antiquated district mechanical system being replaced
What started as a simple swap-out of mechanical systems in two small dormitories in 2007 has turned into a multiphase, cross-campus crusade to change buildings from a 60-year-old central steam heat system to high-efficiency, single-structure hydronic equipment for The Williston Northampton School, a coeducational college-preparatory boarding and day school in Easthampton, Mass. When complete, seven of the largest buildings on the 115-acre campus will have new mechanical components or entirely new systems.
Led by Director of Physical Plant Jeff Tannatt, the school’s maintenance crew has done much of the work, including installation of controls, piping, and many system components. For boilers, massive heat exchangers, and other complex equipment, the school relies on Adams Plumbing and Heating of Adams, Mass.
In the Beginning
Quick boiler changes and the upgrading of water distribution to single-pipe Taco LoadMatch systems in two small dormitories in 2007 inspired the schoolwide transformation.
The first substantial renovation took place in 2008, when an old house was gutted to serve as the starting point for a 26,000-sq-ft dormitory. Two 20-ton geothermal systems heat and cool the building through a network of connected fan coils. The source of energy is the building's own backyard, where 15 boreholes, each 350-ft deep, serve as a year-round source for geoexchange.
Planning
The school's management team, along with Taco Eastern Commercial Regional Manager Jeff Pitcairn, developed a phased plan to update the HVAC systems. The goal: high efficiency and controllability.
"We settled on a phased plan for total divestment of the steam system for several reasons, but funding and the academic calendar played the biggest roles in the decision," Tannatt said. "The economy has impacted us more than we'd expected. Over the past few years, enrollment has dropped, so that’s been a large influence when it comes to project funding. And for installation work, only the summer months are suitable. We can't have off-limit areas, an inability to heat spaces, or heavy machinery moving around campus when there are 500 students here.
"The change in our budget led us to closely compare every component of the system," Tannatt continued. "We definitely didn'’t go cheap, but we really looked at the initial cost and payback analysis of every single part of the project."
Controls
In addition to supplying system components, including circulators, pumps, and large heat exchangers, Taco has provided all of the modular components and expertise for building energy management, monitoring, and comfort control with iWorx, its Web-based, light-commercial controls system.
"What makes iWorx different from other systems," Tom Polansky, technical service engineer for Taco, said, "is that you don't need special tools, software, or computers to do the installation or commissioning."
Once wired, programs are resident in the controller. Through the manipulation of control parameters on the local control interface, engineering time is eliminated, and installation costs drop significantly.
"Another thing that made iWorx attractive was the ability to control all the buildings from anywhere with an Internet connection," Tannatt said. "With the password, our maintenance staff can change the temperature, view fuel consumption, or set timers from any location on campus."
Phase One
During the first phase of the overhaul, several smaller buildings across campus received upgrades. Robert A. Ward Schoolhouse, which houses administration offices and classroom space, was one. The 150-year-old, 20,000-sq-ft brick building was heated by the steam plant. The old 6-in. steam lines running through the walls continuously overheated the lower level. Windows often were open all winter long. Now, the building is heated by hot water feeding a combination of fan-coil units and convectors. Downstairs are two gas-fired, 600-MBH boilers. Taco's LoadMatch system is used to deliver hot water to 42 zones in the building. The circulators are controlled by relays hooked to iWorx modules and thermostats.
"Careful data tracking made it possible for us to see an immediate reduction of energy costs for the buildings retrofitted in the first phase," Tannatt said.
The buildings completed during the first phase of the project averaged a 30-percent savings in energy consumption over previous years—this despite the fact the Northeast saw an unusually long and harsh winter last year.
Phase Two
The early summer of 2011 ushered in the second phase of the retrofit project. The central-steam-plant boilers were taken offline and removed from the 17,500-sq-ft Clapp Memorial Library. The new gas-fired, modulating condensing boiler is connected to an iWorx BLR1 boiler module.
"Until now, steam from the boilers has run through a steam-to-water, tube-and-shell converter, and hot water circulated through a perimeter loop of fin-tube baseboard, aided by fan-coil units throughout," Tannatt said. "This system remains, but the heat exchanger was replaced with a water-to-water unit."
Like the library, the 35,000-sq-ft Memorial Hall dormitory was updated with iWorx controls. The existing steam convectors are being converted to hot water. Each room will have a separate thermostat. Additionally, the building is getting a LoadMatch single-pipe system.
Phase Three
The plan for the summer of 2012 is to tackle Ford Hall. This is a 36,000-sq-ft building housing five faculty apartments and 59 student rooms. As in Memorial Hall, the rooms will be individually controlled with the iWorx system.
Also located in the building is the school’s main dining hall. It feeds up to 550 students and the staff of 250. The Children's Center is adjacent to the dining hall, providing child care for up to 48 children, infant through preschool. Heating and air conditioning for those portions of the building will be wired into the system as well.
"Long term, we hope to build additional geothermally heated and cooled dormitories," Tannatt said. "We are also installing natural-gas condensing boilers in our smaller program buildings and faculty houses. No matter what kind of HVAC equipment we end up installing in the future, the iWorx system will easily adapt to it.
"It's been a long road to energy efficiency already, but we see a very bright light at the end of the tunnel now," Tannatt concluded.
Information and photographs courtesy of Taco Inc.
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