12-02-2016, 04:25 PM
ABSTRACT
Manufacturers of refrigerants and refrigeration and air conditioning equipment, governmental agencies, and environmental groups continue working together toward the goal of reduced environmental impact via reduced emissions and improved energy efficiency. Examples of progress are presented for several sectors of refrigeration and air conditioning, followed by projections for further significant reductions.
Working fluid selection for the myriad of refrigeration and air conditioning applications is based on three factors: safety (toxicity and flammability), environmental impact (stratospheric ozone and climate change), and performance (cooling and heating with required capacity, energy efficiency, reliability, and cost effectiveness). Although this paper will emphasize environmental impact for fluid selection, all of the factors must be evaluated to determine the most appropriate fluid for each application.
INTRODUCTION
Hydrofluorocarbon (HFC) working fluids have been mainly chosen to replace chlorofluorocarbons (CFCs) in refrigeration and air conditioning due to high merits in safety, performance, and no effect on ozone depletion. HFC compounds generally have lower global warming potential values than CFCs, but these values are higher than for fluids such as ammonia, hydrocarbons, and carbon dioxide. To minimize the impact of HFCs on climate change, it is important for industry to continue improving stewardship-inuse practices. This includes selection of HFCs for applications with high societal value, and cradle-tograve management of emissions during HFC production, transportation, use, equipment servicing, and final recovery. Refrigeration and air conditioning equipment is being designed and operated for reduced HFC emissions, and with improved energy efficiency for reduced carbon dioxide emissions.