An experimental study of the active cooling performance of a novel radiant ceiling panel containing phase change material (PCM)

Phase change materials (PCMs) can increase a building’s thermal mass, reducing temperature fluctuations and peaks. However, without active discharge, the PCM’s heat removal capability depends on outdoor temperature fluctuations. The present experimental study investigated the operation and performance of a novel macro-encapsulated PCM panel (MEP) with embedded pipes as an active ceiling cooling component compared to commercially available radiant cooling technologies. The results show that if the PCM was fully discharged, the installed heat storage capacity was enough to shift the cooling demand to off-peak hours. The MEP’s specific cooling power during melting was between 5.3 and 27.7 W/m², with 11.3 W/m² on average over the active ceiling surface for a water supply temperature and flow rate of 20 °C and 140 kg/h, respectively. Under the same conditions, the MEP performance was close to that of the radiant ceiling panels, providing a thermal environment within Category II of EN16798 for 83% of the occupied time. This is significantly better than was achieved by actively cooled gypsum panels with micro-encapsulated PCM whose pipes were in contact with them but not embedded. With its high volumetric heat storage capacity, the MEP could represent a viable thermally active building component for building refurbishment.