Reduction of potential greenhouse gas emissions of room air-conditioner refrigerants: a life cycle carbon footprint analysis

Abstract

Fluorinated gases (F-gases) are considered to be greenhouse gases (GHG) and are widely used as room air conditioner (RAC) refrigerants. This study was initiated to determine the potential to reduce the GHG emission of the RAC refrigerants by calculating their life cycle carbon footprints (CFPs). The life cycle of a refrigerant includes the processes of production, filling of RACs, service, disposal, and energy consumption. The refrigerant functional unit was assumed to produce 1 kW of cooling capacity. The assumed calculation conditions included an RAC service life of 10 years and a unit usage use of 2 h per day, 100 days per year. Specifically, the GHG emission reduction potential of refrigerants was further analyzed based on 15%, 30% and 50% refrigerant recycle rates scenarios.RAC refrigerants were divided into three types: high global warming potential (GWP), middle GWP and low GWP. Analysis of the results indicated that the life cycle CFPs of high GWP refrigerants were larger than those of the middle and low GWP refrigerants. Service and disposal processes contributed most to RAC refrigerants' life cycle CFPs.There are two ways to reduce the GHG emission of RAC refrigerants. One approach is to avoid direct GHG emissions during the disposal process. When the refrigerant recycle rate was improved from 5% to 15%, 30%, and 50%, the reduction of GHG emission of the refrigerants increased by 5%, 12%, and 20%, respectively. The second method is to substitute middle and low GWP refrigerants for high GWP refrigerants. This method can lead to a GHG emission reduction of at least 45.57%.