Dynamic Thermal Behaviour of Two Newly Developed PCM Cooling Ceiling Prototypes
Abstract
In this work, two prototypes of PCM cooling ceilings were investigated regarding their dynamic thermal behavior. Both prototypes address the improvement of thermal contact between PCM, cooling fluid and the ceiling surface, but each with other priorities. The main difference between the two PCM cooling ceilings is the positioning of the PCM layer. In one cooling ceiling construction, macroencapsulated PCM is put on top of the water pipes of a conventional cooling ceiling panel. In the second ceiling construction the PCM containers are between the ceiling panel and the water pipes which are directly connected to the backside of the PCM containers. To characterize the thermal performance of both prototypes, temperatures and heat flows for the three occurring operation modes ‘passive cooling’, ‘active cooling/regeneration’ and ‘active heating’ were recorded. The measurements were performed using a novel measurement setup that enables dynamic thermal measurements on single building elements like wall elements or cooling ceiling panels. The results reveal the advantages and disadvantages of both ceiling constructions, one being a good compromise between passive and active operation modes, and the other emphasizing the passive cooling mode by reducing the thermal resistance between ceiling surface and PCM. Meanwhile, both ceiling types are integrated in the recently constructed Energy Efficiency Center and undergo a long term monitoring.
Keywords
Phase change material (pcm), Cooling ceiling, Passive cooling, Latent heat storage