Controlling Temperature using Dampers in Duct Work

[sasasa1600]

Dont know if i misunderstood you but in the summer cold air drops so the upstairs

gets hotter same as winter .

[jcc2150]

@sasasa1600 +1, its just normal natural convection...heat always rises...

[khonglap]

I request videos calibrate thermostat ?. There two types Direct Acting and reverse acting thermostat. Those are control the damper actuator to open/closed.Please help if you know how ?. Thank you very much for your help. Thank you very for your time post those videos for millions people viewers..