Temperature and average turbulent airflow distributions in the 3D model of a living-room with solar radiation modelling are considered using ANSYS CFX software. The distributions and heat balance are calculated according to the solar radiation source through the window and the pressure difference between openings in opposite walls. The airflow velocities and indoor temperature, including its gradients, are also analysed as parameters of thermal comfort conditions. It is shown that the solar radiation source has an essential influence on the heat balance of the room and on comfort conditions.