A charging control strategy for active building-integrated thermal energy storage systems using frequency domain modeling

• Charging control strategy for active building-integrated thermal energy storage (BITES) systems.
• Charging rates calculation with frequency domain models.
• Calculation procedures for active BITES systems with and without airflow to zone.
• A simplified model for active BITES systems with airflow to zone.

Primary space conditioning can be provided through active building-integrated thermal energy storage (BITES) systems, such as radiant space heating through concrete slabs. This approach can reduce peak space conditioning demand and energy costs while satisfying thermal comfort. However, thermal charging rates need to be predictively controlled due to the slow thermal response of BITES systems. This paper presents a charge control strategy using frequency domain models and room air temperature set-point profile as input. The models were previously verified with full-scale experiment data. The calculation procedures are demonstrated on active BITES systems with and without airflow to zone. Results show that the calculated charging rates satisfy the desired room air temperature set-point profiles. This control strategy is important for integrating the design and operation of active BITES systems because frequency domain models also provide important design information.