Justin P. Kauffman

A reduced global warming potential replacement for HFC-134a in centrifugal chillers: XP10 measured performance and projected climate impact

The performance of XP10, a new refrigerant with a reduced global warming potential, in a centrifugal chiller designed for HFC-134a with a cooling capacity of 1969.44 kW (560 tons) was measured under full- and part-load conditions and compared to performance with HFC-134a. Measured chiller energy efficiencies with XP10 were comparable to those with HFC-134a. They resulted in 0.6% higher energy consumption for XP10 when integrated over a representative profile of partial loads as described by AHRI Standard 550/590 (AHRI 2003). Based on the measured chiller performance, XP10 could be considered a near drop-in replacement for HFC-134a in centrifugal chillers. It could replace HFC-134a in existing chillers or enable optimized new chiller designs without extensive equipment and no flammability code modifications. The total equivalent warming impact of a chiller with XP10 was estimated under representative scenarios and compared to total equivalent warming impact with HFC-134a. Use of XP10 could significantly reduce chiller global warming impact relative to HFC-134a, when chiller refrigerant losses are unavoidably high or when electricity is generated with low GHG emissions. XP10 has the potential to be a more environmentally sustainable future option for medium-pressure centrifugal chillers.