The single-stage ERS using pure refrigerant as a working media can be used for air-conditioning with
the COP on a level of 0.25-0.45 at tgen=85°C, tcond=35°C, teva=12°C. The two-stage ERS can be used to
generate cold at negative temperature (-15°C) provided that the cold generation rate is 1 to 10-15
comparably to air-conditioning mode at +12°C. In that case maximum achievable integral COP will be
0.25-0.3