Spatial Representativeness of the Thermostat and Virtual Sensing of a Representative Point in a Ward-Type Space

Ward cooling is controlled by a single thermostat, yet whether it represents the mean room temperature is rarely evaluated. Existing virtual sensing reconstructs values at predetermined locations rather than identifying which location should be the reference. This study locates that reference point, tests its stability as the thermostat and occupant move, and estimates it from existing control signals. Air temperature and humidity were measured at 5-min intervals at 21 plan locations and three heights in a 16.03 m2 ward-type test room without mechanical ventilation, a 70 W heated cylinder as occupant, in six configurations. The instantaneous spatial deviation reached 4.5 °C. Against the room mean, the thermostat gave a slope of only 0.52 and read high by up to 0.86 °C, whereas one point gave 0.98 and was selected in five of six cases; training-window-only selection returned the same point. Estimating it from four control signals cut the thermostat’s tracking error by 41%, from 0.291 to 0.172 °C, and reproduced the point to within 0.222 °C when trained on five cases and tested on the sixth. Representativeness tracks the deviation field, which was invariant across configurations, so the point needs to be identified once per room. Comfort and energy were not measured.