1. Introduction
The Montreal Protocol of the year 1987 underlined
the need of CFC and HCFC substitutes [1,2]. R22 is the
most widely employed HCFC working fluid in the
refrigerating and air conditioning plants. The only dropin
substitute for R22 is R407C, a zeotropic mixture of
R32/R125/R134a (23/25/52% in weight) with a temperature
glide of 5–6 K depending on the operating
conditions. Its use, however, is usually associated with a
reduction of the overall energetic performance of the
plant.
In order to balance, to some extent, the decrease in
performance of the plant, accurate design procedures
are needed. The relative sizing of each of the components
of the plant is crucial for cycle performance. For
this reason, the accurate prediction of heat transfer
characteristics in condensers and evaporators is
required. In this study R22 and R407C heat transfer
coefficients during condensation are evaluated by means
of an experimental vapour compression plant.
condensation are reported.