For hot rooms, exhaust fan will come on when outside temp drops below preset level, electric powered window will open

2 temp sensors 1 for inside 1 for outside
switch
exhaust fan
Motor for window
wifi or wired Arduino PC
smartphone app module

Program the Arduino if temp is above a set temp inside and temp outside drops below a set temp then turn on exhaust fan once temp has dropped inside below a set temp then turn off exhaust fan

Tau.Neutrino said:

For hot rooms, exhaust fan will come on when outside temp drops below preset level, electric powered window will open

2 temp sensors 1 for inside 1 for outside
switch
exhaust fan
Motor for window
wifi or wired Arduino PC
smartphone app module

Program the Arduino if temp is above a set temp inside and temp outside drops below a set temp then turn on exhaust fan once temp has dropped inside below a set temp then turn off exhaust fan

Good luck.