NORTH RIDGEVILLE, OHIO—As most school districts grow and replace their 40- or 50-year-old buildings, many are moving toward larger intermediate facilities, taking a load off their elementary schools. This inevitably alters the way school buildings are being built. The new, 258,000-sq.-ft., Grades 3-8, North Ridgeville intermediate school near Cleveland, for example, is following a fairly new trend in educational facility construction: the buildings are divided into distinct areas that actually function as independent schools, all under one big roof.
“This building acts as four facilities within one building envelope,” said Richard Dopatka, project manager for ICON Construction Solutions, LLC, the Construction Manager at Risk for the Project. “They all function independently, are divided by firewalls, and are served by separate mechanical rooms. This approach has security, logistical and teaching advantages that more school districts are utilizing.”
ICON was specifically created to provide Construction Management at Risk project delivery for Ohio public entities, with a specific focus on K-12 facilities like North Ridgeville’s new $54 million school.
Soon to accommodate more than 2,000 3rd through 8th graders, the North Ridgeville intermediate school project broke ground in July 2015, with completion set for this summer. Some of the challenges that came up were expected, while others came as a surprise.
“Coordinating with the other trades on a project this size is always a big consideration,” said Mike Clark, project manager, MW Mielke, Medina, Ohio, the subcontractor performing the HVAC and plumbing portion of the job.
“Late in the design phase, we learned that the amount of above-ceiling space available to us was roughly half of what we expected. That threw us a curveball. We ended up having about 2-ft. of overhead space to work with, but still managed to keep most of the ceiling heights at 10-10½-ft.”
Mielke’s work on the North Ridgeville project began in early 2016 as the building shell came together. A 12-man crew was onsite for the duration of the project, supplemented at times with more manpower as needed.
The need to pack power, fire suppression, plumbing, communication lines and ductwork into the limited space required installers and engineers to go back to the drawing board. J.M. Verostko Inc., an MEP firm out of Youngstown, Ohio, designed the plumbing and mechanical systems for the new school. Their assistance accommodating design changes throughout the project was critical.
Changing the size and shape of ductwork was necessary to make all the components fit in the tightened overhead space. Fortunately, the design of both the HVAC and plumbing systems proved flexible enough to allow the alteration without major changes in equipment or the allotted time schedule.
The challenge of fitting the HVAC and plumbing components into a smaller space was aided by the fact that J.M. Versotko and MW Mielke took a compartmentalized approach to equipment installation. Rather than a single, large mechanical space, their approach was to have seven mechanical rooms, all serving different portions of the school.
“We’ve really grown to like the numerous mechanical and plumbing system approach, and it’s almost a necessity on a building this size,” said Clark. “Because of the building’s proportions, the sheer size of equipment, piping, ductwork, etc., would have simply been prohibitive. They systems act independently of one another, just as the respective portions of the building do.”
The school — and the systems that serve it — was designed as four different areas, each with a specific task. Locker rooms, gymnasiums, classrooms, administrative offices, laboratories, kitchens and cafeterias all have very different loads and ventilation needs. Within the building, these are all arranged in a sensible fashion in regard to both student traffic and mechanical system design.
On the plumbing side, a localized approach to supplying domestic hot water was used. There are four mechanical rooms that feature DHW equipment, which that share a space with larger HVAC components. At each of these locations throughout the building’s floorplan, two Bradford White eFSeries commercial water heaters were installed.
Because of proximity to the locker rooms, the mechanical rooms that serve areas One and Three each have two, 300 MBH water heaters, while the mechanical rooms that serve areas Two and Four are have a pair of 199 MBH tanks. All eight of the units have a 100-gallon capacity. The commercial water heaters offer thermal efficiencies between 92 and 99 percent, courtesy of a three-pass heat exchanger, along with an excellent recovery rate.
To maintain immediate availability of hot water at all fixtures, Mielke plumbers installed dedicated hot water recirculation lines, along with Taco pumps and Symmons mixing valves.
Aided by Trane controls for the entire HVAC systems, cooling capacity is provided via two, 300-ton Trane chillers on the roof. Three condensing boilers — two 6,000 MBH and a single, 2,000 MBH unit — are used to supply hot water for the building’s hydronic system.
Rooftop air handlers are used in conjunction with VAV boxes and fan coil units to provide individual room conditioning. The air handlers also feature an ERV wheel for cost-effective ventilation.
The mechanical systems will provide efficient operation for years to come, and are installed in a manner that is conducive to simple service work.