Comparison of energy use and cost in different indirect cooling systems

A case study has been performed comparing 11 different cases of indirect cooling systems in supermarkets. The influence of the selection of cooling-coil / heat exchanger design, display cabinets, type of secondary refrigerant, types of valves, types of pumps and type of system design has been investigated. The cases have been selected to be representative for a large number of supermarkets in Sweden. However, some of the cases are only hypothetical and do no not exist in reality so far. The results show that savings of both energy and money can be significant, by the selection of efficient components and system design. An iterative procedure, for finding the optimal operating point (liquid inlet temperature and liquid flow rate) is suggested. This procedure has been evaluated with good results