Economic comparison of TABS, PCM ceiling panels and all-air systems for cooling offices

High temperature cooling systems have several benefits, such as their ability to create a comfortable indoor environment in an energy-efficient way. Among these systems, those with high thermal mass such as Phase Change Materials (PCM) in integrated components and Thermally Active Building Systems (TABS) are of particular interest, but it is widely believed that these systems are more expensive than traditional all-air systems.
This study investigated the economic performance of TABS, PCM ceiling panels and an all-air system. An open-plan office was used as a case study. The effects of different cooling loads on the economic performance of each system was studied. The global cost and the payback period of each system was compared, following prEN 15459-1 [1].
TABS was the cheapest option, having global costs that were 15%, 5%, 20%, 15% and 2% lower than the allair system for 24, 18, 12, 6 and 3 occupants, respectively. The costs estimated for PCM ceiling scenarios were higher than for the all-air system, but they represent a valid alternative in situations where TABS are not applicable (e.g., renovation projects), especially for high cooling loads, as PCM ceiling panels were only marginally more expensive than the all-air system under high cooling loads.