Heat recovery from refrigeration systems in supermarkets
has been typically done by elevating the condensing pressure
to a level where the coolant fluid of the condensers has the
required supply temperature to the heating system
(Cecchinato et al., 2010), this method is known as fixing the
head pressure. This is being mostly used with systems
running with HFCs where the condensers reject the heat to
a coolant loop with a dry cooler, the indirect heat rejection is
mainly applied to minimize the refrigerant charge.
The environmentally friendly natural refrigerants are seen
to be a long-term solution in refrigeration applications especially
in supermarkets. Supermarket refrigeration systems
working with natural refrigerants provide new possibilities for
heat recovery. Cecchinato et al. (2012) analyzed several
combinations of refrigeration and heat recovery solutions and
compared their energy use to a conventional system. Some of
the natural based solutions showed higher energy efficiency
compared to the conventional one.