In this study, the investigation of indoor airflow in a sub-scale ventilated room is conducted using two approaches: experimental measurements and numerical simulations. The study concerns the prediction of comfort properties in a sub-scale room. Particular interest is concentrated on the three types of ceiling diffusers namely; square, round and swirl (vortex) diffusers. Basic parameters included air temperature, relative humidity, and air velocity are measured and/or predicated at different inlet conditions to obtain thermal comfort indices such as mean age of air, ventilation...