February 2025 CT

Embracing Central Plant CO2 Heat Pumps: A Sustainable Solution for

Community Association Buildings By Ben Rosenzweig, PE and Casey Sky Noon, CoolSys Energy Design, LLC

I n recent years, sustainability and energy efficiency have become top priorities for community association buildings, especially as they seek to reduce their environ mental impact and lower operating costs. A transformative technology that is gaining traction is the use of central plant heat pumps, specifically leveraging low global warming potential (GWP) refrigerants like CO2 (R744), to replace traditional chillers and boilers. This innovative solution offers numerous benefits, from energy efficiency and maintenance savings to significant reductions in carbon emissions. Understanding Central Plant CO2 Heat Pumps At the core of this solution is the CO2 (carbon dioxide) heat pump, a versatile, all-electric system that can be used for both heating and cooling purposes. Unlike traditional chillers and boilers, which often rely on natural gas or other fossil fuels, CO2 heat pumps are powered entirely by elec tricity. They work by transferring heat between the building and the outside environment, using CO2 as a refrigerant

and can be both air- or water-cooled. This method is not only energy-efficient but also environmentally friendly, as CO2 is a naturally occurring substance with a GWP of just one (1). In central plant applications, multiple heat pumps are often deployed to form a robust, centralized system that serves an entire building or community, providing heating and cooling simultaneously. The heat pump system can be integrated into the building’s existing infrastructure, replac ing both the chiller system for cooling needs and the boiler system for heating. This dual-purpose functionality makes CO2 heat pumps a versatile and space-saving option for community associations looking to upgrade their HVAC systems. Why CO2 Heat Pumps Are a Game Changer One of the most significant advantages of CO2 heat pumps is their superior energy efficiency compared to tra ditional systems. Traditional chillers and boilers typically rely

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