NYC Hotel Water Need Meets Electrification Energy Code


To supply efficient domestic hot water for their 350 rooms and banquet facilities, while meeting NYC Energy Code when replacing older, less-efficient water heaters.


The Commercial Tank and Plate Storage Water Heaters provided by DHT, along with Taco ECM pumps and expansion tank more than satisfied both the hotel staff and guests with plenty of hot water for baths, showers, washing machines and hand-washing. The DHT STP Series Commercial indirect is designed to operate with low supply water temps such as from a condensing boiler or heat pump. The multiple HX design allows for heat recovery with condenser water systems to meet the New York City Energy Code. As the nation's largest water heating representative, we have a DHW solution for any application.

Products on the Job

(2) DHT 175-gallon STP Series - Tank and Plate Storage Water Heaters
Taco Viridian high-efficiency ECM pumps
Taco thermal expansion tank

DCAS Bronx Government Building


A 100-year-old building, with a hard to access roof and disjointed heating and cooling systems, causing comfort levels to be far too low and energy expenses far too high. In lock-step with New York’s march toward electrification (Local Law 97 / LL97), NYSERDA (New York State Energy & Research Development Authority) has set an ambitious goal to reduce the 2025 energy-use forecast by 185 trillion BTUs. DCAS has begun a systematic program of installing high efficiency heat pump systems in facilities that will yield the greatest savings.


Beyond hoisting an outdoor rooftop unit through a removed skylight in lieu of a crane, a variety of Fujitsu AIRSTAGE VRF and Halcyon mini-splits were used to replace the steam heating system. The largest room in the building, an expansive conference space, was previously served by a rooftop unit containing a DX coil and semi-hermetic compressor for cooling, and a gas-fired furnace. This did a poor job of responding to the fluctuating human load. “The conference room is now one of nine VRF zones in the building,” Laidlaw says. “We installed three, three-ton ceiling cassettes. We’ve witnessed much better temperature modulation in response to quickly changing loads.”

Other zones in the building are served by a variety of indoor units. Two eight-ton, high-static air handlers are used, one on the first floor and one on the second. Two five-ton vertical air handlers condition various offices. Wall-mount units are used in a storage area and a custodian’s office.

“Standby heat loss from the old steam boiler used to keep the basement hot,” Laidlaw says. “So we installed a three-ton ducted unit to keep the space above freezing.”

In total, eight condensing units and 11 indoor units were used for 46 tons of capacity. Once eight of the 11 VRF systems were running, work on the project was paused. From July through October of 2019, energy use data was collected. Electric and oil bills were compared to the same months of the previous year, showing a 34% savings.

“Because three units serving the first floor weren’t operational during the initial comparison period, we fully expect that the savings will be higher once collection of data includes the entire building—around 50%,” Donovan says. “All the units are now installed, we’re just waiting to connect power to the last few Airstage units.”

Products on the Job

(1) Fujitsu AOUA288RLBVG1 V-II Heat-Pump ODU
(1) Fujitsu ARUH36TLAV High static pressure duct IDU
(2) Fujitsu ARUH48TLAV High static pressure duct IDU
(2) Fujitsu ARUV48TLAV Vertical Air Handler IDU
(1) Fujitsu ARUH96TLAV High static pressure duct
(1) Fujitsu UTY-DTGYZ1 Touch panel controller(Internet access)
(5) Fujitsu UTY-RNRUZ2 Wired RC (Touch)
(3) Fujitsu AOU60RLAVM J-II Heat Pump
(2) Fujitsu ARUV60TLAV Vertical Air Handler
(1) Fujitsu ARUH60TLAV High static pressure duct
(1) Fujitsu AOUA120RLBV1 V-II Heat-Pump ODU
(2) Fujitsu ASUB24TLAV Wall Mount IDU
(3) Fujitsu AUUB36TLAV Ceiling Cassette IDU
(1) Fujitsu UTY-RNRUZ1 Wired Control

Longwood Central School District


For this new construction project the engineers intent was to maximize energy efficiency with improved occupant comfort and control and provide the district with equipment offering redundancy and ease of maintenance.


The original project design scope included two separate Array boilers and a radiant floor heating system throughout the facility, however through the VE process, both the radiant system as well as one of the boilers were omitted. The Riello AR1000’s modular boiler concept still offered the client the redundancy and simplicity of maintenance desired and the use of the DHT SP indirect unit with an A.O. Smith storage tank for domestic hot water functions ensure that the boiler remains in a condensing mode of operation even while in DHW production. A small chemical pot feeder was included for future service and chemical treatment to ensure the system maintains its high level of operation.

Products on the Job

Riello Array AR1000 Boiler
DHT SP Indirect Hot Water Heater
A.O. Smith TJV Domestic Hot Water Storage Tank
Taco FI Base Mounted Pump(s) w/ Taco SmartDrive VFD(s)
Taco 4900 Air-Separator
Taco CA Expansion Tank
Wessels Chemical Pot Fill Unit

USPS Facility Jersey City


Client was looking to replace old, inefficient boilers with high efficiency condensing boilers.


Wales Darby assessed the needs of the client and building and suggested the Riello RTC boilers packaged with Taco pumps and hydronic accessories, magnetic filter, and venting. This complete solution provided the customer with a higher performance system and lower utilities.

Products on the Job

(6) Riello RTC-8000 Boiler(s)
Taco FI, KV, 1900, and 1600 Pumps
VFDs, Hydronic Accessories, CA Expansion Tanks
Taco 4900 Air/Dirt Separator, Magnetic Filter
16” Venting

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