  Researchers have extensively explored predictive control strategies for
controlling heating, ventilation, and air conditioning (HVAC) units in
commercial buildings. Predictive control strategies, however, critically rely
on weather and occupancy forecasts. Existing state-of-the-art building
simulators are incapable of analysing the influence of prediction errors (in
weather and occupancy) on HVAC energy consumption and occupant comfort. In this
paper, we introduce ThermalSim, a building simulator that can quantify the
effect of prediction errors on the HVAC operations. ThermalSim has been
implemented in C/C++ and MATLAB. We describe its design, use, and input format.
