Control of Thermally Activated Building System Considering Zone Load Characteristics

Abstract

The objectives of this study were to investigate the thermally activated building system (TABS) mechanism for appropriate use of the system and to apply the proper concept of TABS for each zone by using different TABS control strategies. In order to examine the TABS mechanism, dynamic simulation with EnergyPlus was used to model the office building with TABS, because the radiant heat exchange characteristics of the TABS according to the time variable was critical. The typical control concept of TABS, self-regulation, was applied in the simulation by setting the supply water temperature as room setpoint temperature. As a result, the advantage of self-regulation can be amplified by utilizing the entire thermal mass of the TABS, which can be executed by customizing to target a specific type of load. Since the large area of the office building may comprise different loads in different zones, the TABS control according to the different zone loads were proposed. By separating the control strategy from zone to zone, the proposed control strategy improved the thermal comfort by 5%, reduced peak heating load by 10%, reduced cooling load by 36%, and decrease the total energy consumption by 13%. This study demonstrated a possible improvement on self-regulation of TABS with separate zone controls.