A system for monitoring thermal comfort of a room. Sensor data concerning temperature, relative humidity, air speed and air flow may be collected from the room. The sensor data may provide thermal comfort level information about the room. The level information may be quantified in terms of a thermal comfort level index, such as a predicted mean vote, which can be used to identify one or more thermal comfort levels in the room with a numerical measure. The one or more levels may be portrayed as a visualization in terms of a 3D plot of temperature, humidity and air speed, several 2D plots, a dashboard, or other items. The visualization may easily enable one to see where setpoint adjustment is possible in a heating, ventilation and air conditioning system to save energy while maintaining thermal comfort acceptable to occupants in the room, whether during a heating season or a cooling season.