Natural ventilation is crucial in poultry and pig houses in regions without frost. Big Dutchman provides the perfect computer for controlling natural ventilation in your barn at a reasonable price. The system uses a well-proven concept employing roller curtains with electric winches on both long sides of the building to control the air exchange. Breezy controls each curtain automatically and independently of each other, based on the temperature. It is also supported by data from a weather station.