Model predicting the state of the heater with the outdoor temperature and occupancy.
When the space is unoccupied, the heater is always off. When the space is occupied, the lower the outdoor temperature is, the higher the chance to turn on the heater.
The model is documented in the paper "Nichol, J., 2001. Characterizing occupant behavior in buildings: towards a stochastic model of occupant use of windows, lights, blinds heaters and fans. In Proceedings of building simulation 01, an IBPSA Conference."
The model parameters are regressed from the field study in the UK in 1998 from 3600 naturally ventilated buildings.