As propane prices climbed across Hawaii, a beachfront resort sought a more efficient way to meet its domestic hot water demands without increasing electrical infrastructure or sacrificing redundancy.

Working through an Energy Savings Performance Contract (ESPC), the resort partnered with an energy services provider to upgrade both its domestic hot water and chiller systems. The goal was to reduce propane dependence while maintaining reliable hot water service for 350 guest rooms, laundry operations and a high-volume commercial kitchen.

The challenge was delivering that capacity while integrating with existing infrastructure, including storage tanks and electrical service.

Reducing Fuel Dependence Without Major Infrastructure Changes

The resort needed a system capable of handling large-scale domestic hot water loads across two separate buildings while avoiding the cost of upgrading electrical service.

That meant finding a solution that could maximize efficiency, work with the existing storage system and provide reliable backup during peak loads or maintenance periods.

Lync developed a hybrid system built around an Aegis water-source heat pump water heater, a new 300-gallon Lync storage tank, the reuse of the resort’s existing storage tank, and three AERCO Innovation high-efficiency gas-fired water heaters for backup.

The system was engineered to support hot water demand across 350 guest rooms, five commercial washing machines and a large commercial kitchen.

Heat Pump System Tied Into Existing Chiller Loop

A key part of the design was integrating the Aegis heat pump with the resort’s existing chiller water loop, which operates between 50°F and 55°F.

This setup allowed the heat pump to generate domestic hot water while simultaneously removing heat from the chiller loop, effectively adding cooling capacity back into the hotel’s HVAC system.

Two recirculation loops—one operating at 120°F and another at 140°F—were incorporated to meet varying hot water requirements across the property.

By leveraging both heating and cooling loads, the system achieved a combined coefficient of performance (COP) of 6.4.

Built-In Redundancy for Continuous Hot Water

To maintain uninterrupted service, the hybrid plant used three AERCO Innovation gas-fired water heaters tied into the resort’s existing propane connections.

These units automatically provide full backup whenever the heat pump is offline or additional hot water capacity is needed.

The approach gave the resort lower operating costs and system redundancy while avoiding the higher first cost of building a larger all-heat-pump plant.

Reliable Performance With No Service Callbacks

Since startup, the hybrid system has operated as the resort’s primary domestic hot water source, delivering stable performance while reducing propane consumption.

Josh Jackson, Sales Engineer for Lync’s representative in Hawaii, noted, “It is extremely rare for all HVAC and plumbing equipment not to have a callback in 1.5 years of operation, but since startup, there have been none.”

The completed project delivered an upgraded domestic hot water and chiller system with no upfront capital cost to the resort through the ESPC model. In addition to long-term energy savings, the hybrid configuration improved cooling system efficiency by offloading the condenser water loop while maintaining full domestic hot water redundancy.

To learn more, visit Lync at www.lyncbywatts.com, and visit Aerco at www.aerco.com.