Abstract: Various embodiments of the teachings herein include methods of estimating a heat transfer via one or more thermal energy exchangers. An example method includes: acquiring a signal for a setpoint temperature; acquiring a signal for an inside temperature at a site; acquiring one or more signals indicative of positions of valves of the thermal energy exchangers; producing a value of setpoint temperature from the signal; producing a value of inside temperature; producing a value of position from the one or more signals; providing a calibrated model with the value of setpoint temperature and inside temperature and position; and using the calibrated model to estimate the heat transfer via the one or more thermal energy exchangers.