Commercial Architecture October 2017 - 46

PROJECT

hvac
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, 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.

Clockwise from left. The 13-story brick building that houses Ronald McDonald House New York 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.
Comfort for families away from home was one of the key considerations for the retrofit.
Two, high-efficiency Laars NeoTherm boilers supply backup heat and cooling to the structure, providing guestroom comfort.

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

ration plants in New York State ranging from 75 kW to 10

"Making the changes necessary to convert to a CHP

critical, even more so than in a conventional heating ap-

mW, and Integrated has flawlessly maintained our facility

system would have yielded a seven or eight-year pay-

plication," said Don Rathe, president of Rathe Associ-

for years. Ike was a Navy submariner. To say he's meticu-

back," said Cafer. "But the charity wanted to make huge

ates, Farmingdale, NY, the manufacturer's representative

lous is an understatement."

strides toward sustainability, occupant comfort, and cost

firm whose professionals helped to specify components

At every step, Farrell was intimately involved with the

avoidance, so the decision was made to remove nearly all

for the hydronic system and supplied the boilers. "In ad-

renovation. His understanding of the building and its ex-

old mechanical components and start with a clean slate.

dition to carrying the heating and snowmelt loads, the

isting systems proved to be invaluable.

This only pushed the retrofit's simple payback out three

cooling system would also go down if the boilers failed to

more years, which is very impressive."

run. "Given the physical state of some of the children at

IF BEFORE HOW

Beyer and Cafer will attest to the growing adoption of

RMH, the role of the boilers becomes essential to their

In 2011, long before any plans for a retrofit were drawn

CHP technology in the Big Apple; up nearly 400% in the

health and year-round comfort conditioning," added

up, Energy Concepts began a feasibility study to deter-

past decade. Cafer explained that Hurricane Sandy

Rathe. "This was a key reason for specification of the

mine if a CHP plant would be right for Ronald McDon-

stirred great interest in co-gen. While much of the grid

NeoTherms, systems we've found to be extremely reli-

ald House New York or if an in-kind equipment replace-

was down, several buildings they personally worked in

able."

ment offered better value.

continued operation as usual, courtesy of well-designed

"All applications are different, based on energy-use

CHP systems.

Integrated HVAC Systems and Services also replaced
the building's existing domestic-hot-water equipment

trends and the physical structures themselves," explained

"Co-gen has always made sense," he said, "but with

with two 85-gal. instantaneous, indirect-fired water heat-

Cafer, who spends several days each week at the firm's

cheap natural gas, costly power, and an overtaxed electric

ers. A new building-automation system simplifies the

Brooklyn office. "We took a holistic approach; energy

grid in NYC, it makes more sense now than ever."

otherwise complex systems, and a snowmelt zone outside

models were developed based on past use and projected

now keeps guests safe and eliminates costly winter side-

costs." The study was funded in part by the New York

HARDWARE

walk maintenance. Lighting throughout the structure

State Energy Research and Development Authority

Integrated HVAC Systems and Services installed a nat-

was updated with LED fixtures, a joint project between

(NYSERDA), Albany.

ural gas-fired IntelliGen, Bethpage, NY, CHP unit on

Integrated and Innovative Energy Solutions Group-New

After two years of research and data collection, it was

the roof of the 13-story building. The pre-packaged unit

York, Hauppauge, NY (IESG-NY), and also partially

determined that on-site cogeneration equipment would

combines a roughly 600-HP, 12-cylinder reciprocating

funded by NYSERDA.

provide the heating, cooling, and domestic hot water

engine with a 250-KW generator to produce power for

The two-phase project was formidable, but everyone

(DHW) loads while supplying 95% of the building's

the building. Heat from the engine-as much as 1.5-mil-

involved had realistic timeline expectations when work

power needs.

lion Btu under full load-is rejected into a large plate-and-

began in December 2013.

COMMERCI A L A RCHI T EC T URE

OCTOBER 2017

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