On-site co-generation provides the heating, cooling, and DHW loads while supplying 95% of the building’s power needs.
What began in 1974 as a McDonald’s Shamrock Shake-driven fundraiser to help families with sick children is today a network of 322 Ronald McDonald Houses in 57 countries. The first Ronald McDonald House (RMH), in Philadelphia, was meant to serve as a “home away from home” for families spending time in the city for cancer treatment.
More than 35 years later, that focus remains; each house is a comfortable safe haven in close proximity to pediatric medical care. The New York City location is the largest facility of its type in the world.
NYC’s Ronald McDonald House New York, located on Manhattan’s Upper East Side, is unique because it is near 19 cancer treatment and major medical centers. The 13-story brick building provides temporary housing to as many as 84 families and was built in 1989. Though living space within the 70,000-sq.-ft. structure is modern, the systems that served it were original until recently.
“The boiler and chillers were past their life cycle,” said Ike Beyer, owner of Integrated HVAC Systems and Services Inc., Islip, NY, the specialized, 30-person mechanical company that partnered with Rochester-based MEP engineering firm, Energy Concepts, for the design/build retrofit that materialized in 2014. Energy Concepts also has a NYC office. “As a non-profit organization, the project’s payback and sustainability were equally important as the initial cost.”
Beyer worked with Chris Cafer, associate and senior mechanical engineer at Energy Concepts to design and install new systems at RMH. Energy Concepts and Integrated have LEED and CSBA (Certified Sustainable Building Advisor) accredited professionals on staff, and were early adopters of CHP (combined heat and power) —or cogeneration— technology. Decades of experience would ultimately lead to a solution that surpassed facility managers’ expectations of comfort and sustainability.
“From the inception of this this project, the goal was to better serve children and families battling cancer,” said Mel Farrell, BSEE, chief engineer at RMH New York. “As such, we hand selected the team who would move it forward. Energy Concepts has designed over 80 cogeneration plants in New York State ranging from 75 kW to 10 mW, and Integrated has flawlessly maintained our facility for years. Ike was a Navy submariner. To say he’s meticulous is an understatement.”
At every step, Farrell was intimately involved with the renovation. His understanding of the building and its existing systems was invaluable.
If Before How
In 2011, long before any plans for a retrofit were drawn up, Energy Concepts began a feasibility study to determine if a CHP plant would be right for Ronald McDonald House New York or if an in-kind equipment replacement offered better value.
“All applications are different, based on energy-use trends and the physical structures themselves,” explained Cafer, who spends several days each week at the firm’s Brooklyn office. “We took a holistic approach; energy models were developed based on past use and projected costs.” The study was funded in part by the New York State Energy Research and Development Authority (NYSERDA), Albany.
After two years of research and data collection, it was determined that on-site cogeneration equipment would provide the heating, cooling, and domestic hot water (DHW) loads while supplying 95% of the building’s power needs.
“Making the changes necessary to convert to a CHP system would have yielded a seven or eight-year payback,” said Cafer. “But the charity wanted to make huge strides toward sustainability, occupant comfort, and cost avoidance, so the decision was made to remove nearly all old mechanical components and start with a clean slate. This only pushed the retrofit’s simple payback out three more years, which is very impressive.”
Beyer and Cafer will attest to the growing adoption of CHP technology in the Big Apple; up nearly 400% in the past decade. Cafer explained that Hurricane Sandy stirred great interest in co-gen. While much of the grid was down, several buildings they worked in continued operation as usual, courtesy of well-designed CHP systems.
“Co-gen has always made sense,” he said, “but with cheap natural gas, costly power, and an overtaxed electric grid in NYC, it makes more sense now than ever.”
Integrated HVAC Systems and Services installed a natural gas-fired IntelliGen, Bethpage, NY, CHP unit on the roof of the 13-story building. The pre-packaged unit combines a roughly 600-HP, 12-cylinder reciprocating engine with a 250-KW generator to produce power for the building. Heat from the engine—as much as 1.5- million Btu under full load—is rejected into a large plate-and-frame heat exchanger, isolating the CHP unit loop from the building’s various needs for heat.
Three loads draw from the heat exchanger: DHW production, the building’s two-pipe fan-coil units when in heating mode, and three new, 50-ton Yazaki (Canton, MI) absorption chillers on the 12th floor. “Absorption chillers are the nearest thing to a magic box,” said Cafer. “You put hot water in and get chilled water out.” The chiller’s unique lithium-bromide absorption technology lends itself perfectly to CHP applications.
During the shoulder seasons, there’s potential for the CHP unit to produce more thermal energy than the facility needs. In the event there’s excess heat, there’s a dry cooler on the roof for heat rejection.
“Being that the absorption chillers are now the only source of cooled water, both the heating and cooling elements in the building are entirely dependent on a source of hot water,” explained Beyer. “During maintenance of the CHP unit, or in the unlikely event of failure, we needed complete redundancy in the form of condensing boilers. This is the case with almost every co-gen application.”
A pair of Laars, Rochester, NH, NeoTherm condensing boilers provide double redundancy. The larger, at 1.7 MMBtu, more than matches the output of the CHP unit. It alone is able to condition the building regardless of the season. The second, 1 MMBtu boiler is in place for further peace of mind. If the CHP unit is turned off for any reason, the boilers fire together, each modulating to roughly 50% to meet design load.
“The contribution of the boilers in this situation is critical, even more so than in a conventional heating application,” said Don Rathe, president of Rathe Associates, Farmingdale, NY, the manufacturer’s representative firm whose professionals helped to specify components for the hydronic system and supplied the boilers. “In addition to carrying the heating and snowmelt loads, the cooling system would also go down if the boilers failed to run.”
“Given the physical state of some of the children at RMH, the role of the boilers becomes essential to their health and year-round comfort conditioning,” added Rathe. “This was a key reason for specification of the NeoTherms, systems we’ve found to be extremely reliable.”
Integrated also replaced the building’s existing domestic-hot-water equipment with two 85-gal. instantaneous, indirect-fired water heaters. A new BAS simplifies the otherwise complex systems, and a snowmelt zone outside now keeps guests safe and eliminates costly winter sidewalk maintenance. Lighting throughout the structure was updated with LED fixtures, a joint project between Integrated and Innovative Energy Solutions Group–New York, Hauppauge, NY (IESG-NY), and also partially funded by NYSERDA.
The two-phase project was formidable, but everyone involved had realistic timeline expectations when work began in December 2013.
“Unfortunately, cancer doesn’t take a year off for building upgrades,” said Beyer. “Patients and families still needed a place to stay, and the need to maintain a clean, quiet building throughout the duration of the project rose above all else.”
With all rooms full, Beyer, Cafer, and Farrell faced the monumental task of renovating three systems without displacing occupants from a single room or letting comfort levels drop. Their second largest challenge, without a doubt, was working within the small, existing mechanical spaces.
“Because the project started in heating season, we began to demolish the old chillers on the 12th floor while the existing boilers in the basement remained online,” said Beyer. “Meanwhile, the CHP unit, new boilers, and chillers were all rigged to the roof at one time.”
Once the old chillers were removed, the CHP and absorption chillers were installed in time for cooling season, at which point the old boilers were broken down and hauled out. The downstairs boiler room then became a pump room, supplying almost all circulation for the entire structure. All heat exchangers and DHW production equipment are here as well.
“Farrell wanted the very best equipment money could buy; efficiency and dependability were his key concern,” explained Cafer. “Ike and I had to figure out how to make it all fit.” Given their small footprint, high efficiency, and Beyer’s familiarity with the NeoTherm line, the boiler selection process was brief.
“We’ve used Laars boilers for years now, even in conjunction with other CHP projects,” said Beyer. “I have yet to encounter an issue that hasn’t been resolved with a short phone call to the rep, Rathe Associates.
Control and comfort
Over the summer, 2,200 sq. ft. of sidewalks and approach in front of the main entrance were removed and re-poured, but not before PEX was tied down to provide a snowmelt solution. For this portion of the project, Rathe donated material, while Integrated donated manpower to ensure safe winter passage for all guests.
After walking over the clear sidewalk and into the building’s lobby, visitors can now interact with a screen that displays all the mechanical components and how they cooperate to meet the energy needs within the building. The display screen also shows energy use and production in real time, courtesy of a full BACnet control system made by Reliable Controls, Victoria, British Columbia. Among other things, the new controls were necessary to operate the final component of the retrofit, which is still in the planning phases and slated to begin later this year.
“We’re looking to replace the existing two-pipe fan coils with a four-pipe system,” explained Beyer. “It’s more than just an energy consideration; it offers precise control for optimal comfort. The kids staying here are going through chemo and radiation therapy. Some might feel hot while others are shivering. A four-pipe system will allow us to provide heat to one room and air conditioning to the next.”
“Every part of this project has come together perfectly,” said Farrell. “The new fan coils are the final element. This renovation means that for many years to come, the NYC facility is going to continue serving families in some of their darkest hours.”