Experimental investigations of heat transfer in thermo active building systems in combination with suspended ceilings

Thermo Active Building Systems (TABS), described as radiant heating or cooling systems with pipes embedded in the building structure, represent a sustainable alternative to replace conventional systems by using source temperatures close to room temperatures. The use of suspended ceiling in office buildings to cover acoustic requirements hinders the use of TABS. To measure the reduction of the heat capacity, several experiments are performed in a room equipped with TABS in the upper deck and mixing ventilation. The heat transfer is measured for different suspended ceiling covering percentages, occupancy scenarios and ventilation rates. The gained results indicate that the heat capacity coefficient of the ceiling surface is reduced by around 30% when the suspended ceiling covering is 70% of the total ceiling area, and 45% when the covering area is up to 87%. The results also demonstrate that the ventilation rate has a high influence on the convective heat capacity. When the ventilation rate is increased from 1.7 h^-1 to 2.9 h^-1, the heat transfer coefficient increases up to 16% for the same occupancy and suspended ceiling layout.