A simple chiller model for hourly time step applications

For the use in Swiss standards on energy performance of cooled buildings, a chiller model for an hourly time step calculation was needed. Unlike the models found in a literature review, the model aimed at should be based only on the information available from standard performance rating, i.e. COP values for 4 rating conditions. To perform satisfactorily, the semi-physical/semiempirical model had to be refined, which requires the addition of one additional COP value as an input. This refined model shows accurate results for most chiller types that were available for testing. In this paper, the model and its development is explained, and its performance for a range of chiller types upon an application to an annual load profile of a real building is shown.