I reckon the thermostat upper and lower limits should not change with time as there is no AC system on the market that can respond to the outdoor conditions. Having said this, I imagine that users will change the thermostat limits depending on the outdoor conditions themselves. For example, in hot dry climates, when outdoor temperature reaches 40 degrees, one will set the AC to let say 16 degrees but as the outdoor temperature falls down with time during the day they will raise the thermostat to perhaps 18 or 20 degrees until in some cases they can open the windows and shutdown the AC. So should not the thermostat change at least with the season to reflect the occupants’ attitude? If not, how one would calculate the upper and lower thermostat limits for a certain location? What will happen in case of mixed-mode? Does Ecotect use the thermostat range as the comfort band to decide when to open the window? Should we have two sets of limits, one constant representing the thermostat range and another variable representing the comfort band?