The Impact of Refrigerants on the Efficiency of Automotive Air-Conditioning System

Abstract

Over 95% of new cars in the EU have air conditioning which significantly contributes the global warming by emitted flue gases, and of refrigerants with a high global warming potential (GWP). The paper analyzes automotive conditioning systems in terms of energy efficiency. Currently, in these systems the most popular refrigerants are R134a (GWP = 1430) and R1234yf (GWP = 4). There are some controversies related to the impact of R1234yf on human health, especially during road collision and depletion of the system. The tendency in automotive air-conditioning systems is to shift from refrigerants that were safe for man but not to the environment, on ones that are pro-ecological but can be dangerous to human health and life. The article also presents an overview of the most popular synthetic refrigerants used in automotive air conditioning over several decades in Europa, like R12, R134a, and currently used in the new systems—R1234yf. Due to the environmental impact of refrigerants, the EU imposes tougher requirements for these substances. European Commission Directive 2006/40/EC provides that from January 1, 2017, only refrigerants with GWP lower than 150 may be used in air-conditioning system of new cars. This requirement is now met by synthetic refrigerant R1234yf and natural one R744 (carbon dioxide). The environmentally friendly (GWP = 1) and not posing a threat to humans, R744 seems to be a future-proof alternative to refrigerant R134a.