Paper No 123 – Evaluation of lower GWP alternatives to R410A in AC and HP applications – 14th IEA Heat Pump Conference, Chicago, USA
R410A is a refrigerant commonly used in air conditioning and heat pump applications that has become the target to be replaced by lower global warming potential (GWP) alternatives. R-454B with a GWP of 466 has been proposed as a lower GWP replacement for R-410A with similar performance and operating characteristics. Long-term refrigerant solutions are required to provide similar to improved efficiency with comparable capacity while having a GWP of less than 300. This threshold has been identified as an industrywide average in line with global climate commitments. This paper investigates alternative refrigerant options to replace R-410A including R-454B, as well as DR-4 and R-479A with a GWP of less than 300 and less than 150 respectively. Thermodynamic simulations followed by an investigation using a component system model of a 3-ton unitary heat pump are performed. Varying ambient temperatures in cooling operation as well as standard rating conditions for both heating and cooling operation for each candidate are considered, to compare refrigerant performance and to determine their viability as a replacement option. Drop-in performance and adjusted compressor speeds are used to compensate for the capacity penalty the lower GWP options experience to achieve relative COP and capacity within 5% of R-410A for investigated heating and cooling conditions.