Farm building ventilation system

Light panels are used as wall ventilation for cattle housing. The light panels are mounted in slide rails and can be open by moving the panels down on the outer side of the wall. The panels are controlled via steel wires, which are rolled up around a galvanized pipe by means of a gear motor. Opening area is regulated manually via rotary switch, which can be placed as required. Each panel has its own switch. In the closed position there is an opening, which corresponds to about 1 cm of the entire panel length. Light penetrations is good, even when the panels are closed.