merun similar product being use in modern poultry houses... it is a thermostat switch.

pagnareach niya yung temperature na mataas (which can be adjusted to need) say 27 deg C, it would turn the fans on. Then it will turn off naman pag nareach niya yung desired working temp.

the sensors (puedeng multiple sensors) are located where it is necessary.

unfortunately, I forgot where to buy it locally.