Generally, doorways are the part of a cold storage rooms where maximum energy gains and losses occur. The main purpose of this research is to achieve a more efficient energy control for these areas. To do this, a comprehensive study of a climate separation system with highly efficient air curtains has been conducted. Not only the energy consumption has been analyzed but also the carbon dioxide emissions to the atmosphere, as well as the cost effectiveness of different alternatives. The results of the study, from the viewpoint of energy performance and amortization period, show that using high efficiency air curtains as a climate separation is a cleaner and cheaper solution than other commonly used systems. It reduces heat gains and losses through the door of the storage room by 80% compared with a physical separation solution. The simplicity of the installation makes these systems feasible not only in new buildings, but also in buildings under construction or refurbishment. (C) 2014 Elsevier B.V. All rights reserved.