Lync by Watts' Aegis W CO2 water-source heat pump water heater, at AHR Expo 2024
Lync by Watts' Aegis W CO2 water-source heat pump water heater, at AHR Expo 2024

Sales of CO2 Heat Pump Water Heaters Are ‘Doubling’ Yearly in North America, Says Lync by Watts

Decarbonization of water heating is driving sales for multiple manufacturers.

Sales of CO2 (R744)-based commercial heat pump water heaters in North America are “doubling” every year – albeit from a small base – as a result of the movement to decarbonize water heating, said Jake Bucklin, Product Manager, Decarbonization Solutions for Texas-based manufacturer Lync, part of Watts Water Technologies.

Bucklin shared this observation at the AHR Expo 2024, where Lync was exhibiting its Aegis CO2 heat pump water heaters for commercial applications like apartment buildings, hotels, hospitals and dormitories. AHR Expo was held in Chicago January 22–24.

Several other manufacturers were also exhibiting CO2 heat pump water heaters at the event, including Intellihot, Mitsubishi Electric Trane HVAC US (METUS), Transom, ECO2 Systems, Mayekawa and Budzar. “We have more competitors, but we’re all seeing the same growth; we’re not fighting over market share,” he said.

The heat pumps are replacing natural-gas boilers, which are being banned in some locations, noted Bucklin. In addition, building owners are receiving incentives to offset the higher cost of the heat pumps compared to natural-gas boilers. The heat pumps “use less energy so there’s an ROI,” he added.

Bucklin said that CO2 heat pumps “compete well” with heat pumps that use f-gases like R134a or R513A. “We offer hot water in ambient temperatures down to −4°F [−20°C], while those only go down to 35°F [1.7°C],” he said.

The Lync brand and its Aegis heat pumps were launched by Watts in April 2021. Last year the company said its CO2 units were in use across the U.S., with multiple installations in California, Florida, New York and Tennessee. While they can be deployed in most locations, Lync offers an electric storage tank to supplement heating when outside temperatures drop below −4°F.

The CO2 heat pump water heaters are not designed for space heating because of the high “delta T” or temperature differential required. “They can make up to 180°F [82°C] water, but they can’t take back 160°F [71°C] water to the heat pump; it’s got to be 86°F [30°C] or below,” Bucklin said. The system uses a secondary heat exchanger to ensure that the return water is at that temperature.

The Aegis heat pumps come in two models, A (air source) and W (water source). The heating capacity of the A unit ranges from 210MBH to 494MBH (17.5TR/61.5kW to 41.2TR/144.9kW), with a COP from 3.8 to 3.5. The W unit, which uses source water temperatures as low as 18°F (−8°C), offers capacities of 199MBH to 477MBH (16.6TR/58.4kW to 39.8TR/140kW) and COPs from 3.7 to 3.5. They both have a cool-recovery option that provides simultaneous production of cold water along with hot water, further increasing COP.

Other CO2 heat pumps

Other exhibitors of commercial domestic-hot-water CO2 heat pumps at AHR Expo 2024 included Japanese manufacturer Mayekawa and Canadian manufacturer Transom, both displaying units that were unveiled for the U.S. market at last year’s AHR Expo in Atlanta, Georgia, event. A spokesperson for Transom at the 2024 show said Transom plans to deliver units at the end of this year, following certification by Intertek.

Mitsubishi Electric Trane displayed a unit, the Heat2O, it launched in 2021. The heat pump cuts heating costs at least 70% compared to traditional water heaters, according to Dana Fischer, Director of Regulatory Strategy, Mitsubishi Electric US.

While relatively new in the U.S., CO2 hot water heat pumps have been extremely successful in Japan and other Asian markets, like South Korea, for many years.

Transom CO2 heat pump water heat, at AHR Expo 2024
Transom CO2 heat pump water heat, at AHR Expo 2024

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