This paper presents full-scale measurements and simulation results of the thermal performance of a ventilated concrete slab (VCS) with active cooling using cool outdoor air. A methodology for the charge control and sizing of building-integrated thermal energy storage (BITES) systems that can be used for active slab cooling is developed. This VCS, which has a floor area of 30 m² (323 ft²) and a storage volume of about 5 m3 (177 ft³), is located in a near net-zero energy solar house. It serves as an active-charge/passive-discharge thermal mass, as well as the basement slab - it is a BITES system. An on-site test under summer nighttime outdoor condition was performed and the dynamic temperature distribution of the slab was monitored. The measured data is used for the validation of a thermal model under cooling operation. The validated thermal model is then used to predict the thermal performance of the slab under different operating conditions. The simulation results show that under typical operating conditions, roughly 6.3 kWh (21.5 MBTU) of heat (1.26 kWh per m³ of concrete (4.3 MBTU/ m3)) can be extracted by the flowing air from the VCS in 6 hours. A 3-parameter (temperature and velocity of inlet air, and cooling duration) correlation is developed to approximate the thermal energy storage under different operating conditions. Similar correlation can be developed and used for design and control of such systems. The methodology for design and charge control presented in this paper is applicable to other types of BITES systems in different types of buildings.