| 摘要 |
<p>An agricultural building installation suitable for storage of produce or housing of livestock is divided into a plurality of zones, each having at least one temperature sensor 30, and a respective air damper 17. A control device monitors the outputs of the sensors 30 in each zone, one at a time, and then causes air dampers 17 to be opened or closed, to increase or decrease ventilation to a zone. Ventilating air may be pumped into a central duct 11 extending through the building, passing into underfloor passages through opened dampers 17, and then rising upwardly through openings in the floor, so as to pass through stored produce. Alternatively, the dampers may be provided in external walls so as to control natural flow of ventilating air through the building. Extra sensors may be provided for the bottom and top of stored produce (27 and 28) respectively, internal roof temperature (29) and for incoming air temperature (26), the control apparatus adjusting the dampers 17 in dependence upon the outputs of all the sensors. Each zone may have a plurality of sensors 30 the output of which is averaged, and a sensor may be provided for external ambient air temperature. <IMAGE></p> |
