I would like to design a simple night ventilation system with heat recovery (following) implementing a control logic using "hysteresis effect". Where for the upper band if the difference between Temperature of room and ambient is more than 2-degree celsius the system turns on and if less than 1-degree celsius turns off. Similarly, the lower band if the difference between Temperature of room and ambient is more than 1-degree celsius the system turns on and if less than -3-degree celsius turns off. is it possible to design such system?