How an Oahu resort saved $90,000 in hot-water energy
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To see how far commercial water heating has come over the past generation, just look at the two sides of the boiler room at Oahu’s Turtle Bay Resort.
On one side sits the resort’s gargantuan previous system, waiting to be removed. Two large low-pressure boilers about the size of 1,000-gallon tanks, with support equipment including feed pumps and softeners, stand next to two 900-gallon hot-water storage tanks with steam-injection bundles.
On the other side in a large, open area sits the future: two small boxes with digital control panels, which supply the same amount of hot water.
The upgrade is part of a resort-wide transformation undertaken by its new owner, BRE Hotels & Resorts, which acquired the hotel in 2017. The upgrades included a renovation to open up the lobby with massive windows that showcase 180-degree ocean views and a sunken lobby bar called Off the Lip, which overlooks an infinity-edge lagoon and breaking ocean waves. The renovations are ongoing in guest rooms, meeting rooms, and the spa.
But as stunning as those upgrades are, it’s the behind-the-scenes renovations of systems like the water heating, drains, insulation, and plumbing that make facilities director Manny Crawford most excited. “We finally got rid of everything from 1972,” he says. “Now it’s a 2021 upgrade. As a department, that’s probably one of our favorite things that happened through the renovation.”
Upgrading to tankless
Size wasn’t the only problem with the resort’s 40-year-old boilers. While Crawford’s team kept them in top condition, they simply weren’t as efficient as modern systems and required a lot of maintenance and hands-on monitoring. If occupancy was high, the system might struggle to meet the hot-water demand, and the facilities staff would have to manually adjust the valves to get more hot water into the tank or increase the fire rate.
“We always had a 900-gallon tank that we constantly had to warm up to get it delivered, especially if it was going to be used a lot,” Crawford says. “So that was killing us with [how much propane it used] because we always had to constantly reheat that water in that tank.”
Working with a local rep for the replacement project, the resort selected two 1.5-million-Btu on-demand propane water heaters from Intellihot — essentially a heavy-duty alternative to increasingly popular tankless water heater rack systems. The project’s installer, Tony Castaldi of Pacific Boiler in Kailua, Hawaii, sees the technology as a better, more-efficient alternative to boilers in this type of application.
“I’m always for reliability, especially with the hotels,” Castaldi says. “Getting parts on an island can be difficult, especially when they’re one-of-a-kind parts. Intellihot has modular tankless heaters inside the cabinet. Essentially, you pop it out, pop in a new one, and away we go. So it’s really easy to stock those modular heaters as replacements.”
Compared with the old system’s hand-adjusted valves, the Intellihot units also vastly simplify the system controls. “It’s just so dumb simple,” Crawford says. “It’s just pushing the buttons now. If you want to increase the temperature, you go to the plus sign.” The units are monitored by both the manufacturer and Pacific Boiler, sending a fault code that indicates whether urgent service is needed.
Getting rid of the old storage tanks will not only open up about 75 percent of the space in the boiler room but will also provide significant energy savings by heating water only when it’s needed. “We’re looking at a three-year ROI on getting it paid back,” Crawford says. “We’re looking at hopefully $83,000 to $91,000 savings in a year.” Using less propane also plays an important role in the resort’s environmental messaging, alongside its efforts to minimize waste with recycling and reusable or biodegradable products.
Although Crawford’s team evaluated electric alternatives, the systems would have cost twice as much without offering significant energy cost savings. It’s a scenario that’s quite common on the island, Castaldi says, especially given how efficient gas water heaters have become in the past decade.
Crawford was also comfortable maintaining propane storage at the resort. In addition to fueling Turtle Bay’s old boiler system, propane is used for fire pits on the porches around the pool deck and for almost all of the commercial cooking equipment in the resort’s kitchens.
With 450 rooms, a pool area with five bodies of water, and a relatively remote location on the northern tip of Oahu (on the opposite side from Honolulu), the Turtle Bay Resort is a common staycation destination for local Hawaiians looking to escape the crowds. On-site propane ensures that even without access to the island’s synthetic natural gas system, the resort can still utilize the most efficient and affordable water-heating systems to modernize the resort for decades to come.