As can be seen, the developed air cycle system has the same energy consumption as the currently used R12
system. The new R134a system shows an improvement of roughly 20%. Comparing vapor compression systems with
air cycle systems other important aspects can be considered. An important advantage is that the maintenance work
for an air cycle system is less cost and time intensive than for other systems. Taking into account that currently
about 60% of the refrigerant annually charged into the atmosphere due to leakage and maintenance, the total
equivalent warming impact TEWI for the air cycle system is even better than for the modern R134a system (refer
also to Table 1).