11 VENTILATING, WATER SUPPLY AND DISTRIBUTION, HEATING, AND LIGHTING INSTALLATIONS, FOR USE IN BREEDING, FEEDING, WATERING AND MANAGING LIVESTOCK AND POULTRY, NAMELY, CHIMNEY VENTILATORS; WALL VENTILATORS; COMBINED AIR INTAKE AND AIR OUTLET VENTILATORS; AIR INTAKE UNITS; PARTS FOR THESE VENTILATORS AND UNITS