RACA Journal August 2020 | Page 49

Technical BITZER REFRIGERANT REPORT: PART 1 By Bitzer Stratospheric ozone depletion as well as atmospheric greenhouse effect due to refrigerant emissions have led to drastic changes in the refrigeration and air conditioning technology since the beginning of the 1990s. This is especially true for the area of commercial refrigeration and air conditioning systems with their wide range of applications. REFRIGERANT DEVELOPMENT AND LEGAL SITUATION In former years, the main refrigerants used for these systems were ozone depleting types, namely R12, R22 and R502; for special applications R114, R12B1, R13B1, R13 and R503 were used. The use of these substances is no longer allowed in industrialised countries, but the use of R22 has been extended through transitional periods. The so-called ‘Kigali Amendment’ was adopted in 2016 under the Montreal Protocol, in which a step-by-step reduction of HFCs (‘HFC phase-down’) was agreed upon, effective from 2019. The following report deals with potential measures of a short- to medium-term change towards technologies with reduced environmental impact in medium and large size commercial refrigeration and air conditioning systems. Furthermore, the experiences so far and the resulting consequences for plant technology are discussed. SUBSTITUTES FOR R22 IN AIR CONDITIONING AND HEAT PUMPS As the HCFC refrigerant R22 (ODP = 0.05) is accepted only as a transitional solution, a number of chlorine-free (ODP = 0) alternatives have been developed and tested extensively. They are being used for a large range of applications. Experience shows, however, that none of these substitutes can replace the refrigerant R22 in all respects. Amongst others there are differences in the volumetric refrigerating capacity, restrictions in possible applications, special requirements in system design and considerably differing pressure levels. According to the specific operating conditions, various alternatives may be considered. Apart www.hvacronline.co.za RACA Journal I August 2020 47