Nestled on the shores of Waikiki, Hawaii, a tranquil, elegant sanctuary has welcomed guests for more than a century. Halekulani – which means “house befitting heaven” – is just that: a place where every need is anticipated and gracious hospitality abounds

Hospitality & Tourism

Waikiki, Hawaii

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It was only fitting that, when management at the 453-room luxury hotel decided to upgrade its mechanical room, they turned to Rinnai. "The two older boilers the hotel depended on for hot water were sometimes unreliable,” said Randy Hiraki, president of Commercial Plumbing, an employee-owned contractor with deep roots in Hawaii and across the Pacific. “We were confident that Rinnai had the systems, expertise and application engineering capabilities to help us implement a premiere system for a premiere hotel.” Hiraki and Commercial Plumbing gave Rinnai’s team the green light to build a system that would deliver the kind of plentiful, uninterrupted hot water guests at Halekulani expect.


"It was our dream to introduce the Halekulani engineering team to tankless, redundancy and BMS compatibility,” said Bo Vosika, the Hawaii rep for Zurier Company, a leading manufacturer’s representative for Rinnai. “I was tasked to ensure endless hot water,” said Vosika, “and to make sure the water is extra hot, since most of the clientele desire that.” The application engineering team at Rinnai were then consulted to size the system for maximum redundancy and performance in accordance to the fixture count, budget and overarching project goal of abundant hot water.

Commerical Tankless Water Heater

The Highest Standard of Reliability

  • 97% Thermal Efficiency
  • Integrated temperature control up to 185° F
  • Up to 24 water heaters can connect as one hot water system
  • Up to 12 water heaters can common vent with either 6" PP or PVC/CPVC
  • Space saving indoor or outdoor units in natural gas or propane
  • Units can be ordered on pre-assembled wall-hanging or free-standing rack systems CU199i


Halekulani needed the new system to serve not just one, but two hot water demands: a domestic system that supplies their guests’ hot water with redundancy and an in-house laundry system. The finished 6.4-million-BTU system features 20 Rinnai CU199IN commercial condensing tankless water heaters for domestic demand and 12 CU199IN units for the laundry system. The domestic system also uses a 1380-gallon storage tank, while the laundry system features an 800-gallon tank. Application engineers at Rinnai provided design guidance throughout, to ensure the plumbing system was in accordance with the drawing, and the storage tanks and recovery pumps operated optimally for maximized recovery and consistent temperature delivery.

All 32 Rinnai tankless units are tied into six UL-listed Rinnai BMS Gateways, each supporting up to six heaters. The gateways plug into the hotel’s BACnet system, which provides a common communication protocol allowing building equipment and devices to communicate across systems.

Now maintenance engineers and personnel at Halekulani can readily view and control virtually every aspect of system function – from turning tankless units on or off and adjusting water temperature to monitoring flow rates and operation hours – all from their computers, phones or the Rinnai handheld touchscreen located near the tankless units that interfaces with the building management system.

“It was fun to be on a team with so many brilliant people who put this system together,” said Zurier’s Vosika. “The management at Halekulani, along with Randy Hiraki, took the concept and created a real-world application that is literally a masterpiece, both mechanically and aesthetically. There’s no doubt Halekulani will reap the benefits in operational efficiency and guest satisfaction.”

For more information on commercial water heating solutions, maintenance services and a free sizing consultation by Rinnai Applications Engineers, call 866-383-0707 or visit

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