In smaller greenhouses, a manual program opened and closed yourself could be installed. These work simplest when the screen materials is supported by a track system.
Start time – when in the morning will the display screen system start operation
Stop time – when in the afternoon will the screen system stop operation
Light level – at what light intensity will the screen become activated either to open up or close
Maximum/minimum temperature – what are the limits of temperature desired
Maximum/minimum humidity – What are the limitations of humidity desired
Gap positions – this units the percent open up or close position under different circumstances such as in early stages a winter morning to reduce thermal shock or during the summer to supply better shading. The gap guidelines and speed of motion can be controlled in a few systems.
Time delay – below changeable climate this avoids frequent opening and rack drive for greenhouse china closing
Wind speed – To lessen heat loss, the screen could be closed early under high wind speed conditions
Snow detection – this may open the display screen and turn on heat when it begins to snow.
The standard system uses nylon monofilament or stainless cables to support the screen materials. The screen material can possibly rest along with the network of cables or be suspended by hooks from the cables. A gearmotor powers a drum or rack and pinion that movements the industry leading of the screen materials. Control is either with a manual change or electronic controller.
Based on the above, the grower must enter the next parameters into the controller:
A climate station is needed to provide outdoor light level, temperature, humidity, wind and rain or snow conditions.