Case study of a desiccant evaporative cooling system in a Danish office building: System modeling from long-term monitoring data

With global warming, the demand for cooling energy is expected to increase, even in moderate-climate regions. In heating-dominated countries equipped with a district heating network (DHN), the usage of the DHN in summer is reduced and low-grade energy in the form of heat is widely available. Denmark has implemented a pilot project to harness low-grade energy from its local DHN to provide cooling to buildings using evaporative cooling technologies. The pilot project building is an office building equipped with a desiccant evaporative cooling system (DECS). The latter has been monitored to allow a direct and accurate assessment of the energy performance of such HVAC systems. In the present paper, a model of the DECS installation has been developed. Based on long-term monitoring, the ability of the model to predict the behaviour of the system components and to simulate the system control strategy has been studied. Despite the limitations due to the monitoring setup and the simplifying assumptions of the numerical model, it was established that the model fairly predicts real DECS behaviour, regarding supply air conditions, energy and water consumption and system operation.