Environmental impact of possible replacements for R22.

This paper presents a comparative analysis of a number of potential replacement refrigerant for R22 used for different refrigeration plants and heating pumps from an environmental impact perspective (the TEWI coefficient). In order to assess environmental impact of these potential substituents, the following refrigerants have been considered: a) substitutes currently used in existing systems: R134a, R290, R600a, R152a, R507, R407C, R404A, R410A; b) new substitutes, recommended for new systems: R417A; R422A; R424A; R427A, R428A. The paper covers a comparative analysis of three types of refrigeration plants which operate with different refrigerants from a factor TEWI perspective, as follows: 1. air conditioning-split unit, with a cooling capacity of 10,55 kW (tin = 25°C, tambiant = 35°C); 2. air cooled chiller, with a cooling capacity of 11.3 kW (tchilled water in/out = 7°/12°C, tamb = 35°C); 3. air cooled refrigeration system using direct or indirect evaporation for cold storage (medium temperature space tint = 0°C and low temperature space tint = -20°C, tambiant = 35°C), cooling capacity 11.3 kW.