A study on optimum insulation thickness of cold storage walls in all climate zones of Jordan

Cooling of cold storage space in hot climates consumes significant amounts of energy, which can be conserved with the help of thermal insulators. The main goal of this study is to conduct a life-cycle cost (LCC) analysis over a period of 10 years in order to determine the optimum insulation thickness (OIT), energy saving, and pay-back period for minimizing installation and operational costs of cold storages in any given climate zone of Jordan. These climate zones were represented by four Jordanian cities, i.e., Amman, Mafraq, Ma'an, and Aqaba. In this analysis, three commercially available insulation materials were selected, namely Rockwool (RW), expended polystyrene (EPS) and polyurethane (PUR), for a wide range of cold storage temperatures (0, -5, -10, -15, -20, -25, and -30 degrees C). Electricity was considered as a source of energy. It was found that EPS has the best energy savings and shortest payback period compared to other insulation materials. Therefore, its use in cold storage exterior walls insulation, with OIT suggested in any climate zone of Jordan, is economically feasible. An insulation characteristic curve for EPS was prepared, which includes the OIT and cost saving over a wide range of cooling degree-day and coefficient of performance (COP) values.