Abstract
Utilization of naturally occurring and ecologically safe substances as working fluids in heat pump systems represent an environmental friendly and long-term solution to the HFCs. The most important natural working fluids include ammonia, hydrocarbons and carbon dioxide. Ammonia heat pumps represent an energy efficient alternative for heating and cooling of non-residential buildings as well as for district heating and cooling systems. This paper discusses the main characteristics of ammonia heat pump systems for heating and cooling of non-residential buildings including thermodynamic cycle analysis, recommended system design and dimensioning, component selection and system performance. The impact of the heat distribution system on system performance is also discussed. A number of large-capacity ammonia heat pump systems in Norway are presented including installations in office buildings, hospitals and district heating and cooling systems