In this book, the thermal and airflow processes of stratified air distribution (STRAD) systems are experimentally and numerically illustrated. The applications of STRAD systems with separate locations of return and exhaust grilles in three different spaces, namely office space with low ceiling level (lower than 3 m), high space with middle ceiling height (5 m) and large space with very high ceiling level (8 m), were numerically investigated with regard to both thermal comfort and energy saving. Several crucial design parameters for STRAD systems were studied, including the locations of diffusers, the occupied zone cooling load that will be used to determine the required supply air flow rate, and the cooling coil load that will be used to determine the equipment size, and significant results were obtained. Based on the findings in this book, special considerations are also suggested to consultant engineers when designing a STRAD system.