Recent advances in ammonia LPR systems for freezer applications.

Recent advances have led to the development of low charge, high efficiency ammonia condensing units which allow the use of the low pressure receiver system in freezer applications. This paper looks at the role of aluminium coil evaporators and how they help to reduce system charge and increase system efficiency. The paper will also examine how this technology can be combined with air cooled condensers, automatic oil return and reverse cycle defrost to provide reliable and efficient ammonia condensing unit systems. It will be shown that these modular, packaged systems can be designed with a significantly lower ammonia charge and efficiency in excess of a central ammonia plant. The paper will conclude that air cooled ammonia condensing units can be combined with aluminium coil evaporators to provide a low charge, high efficiency refrigeration system for freezer applications.