In smaller greenhouses, a manual system opened and closed by hand could be installed. These work simplest when the screen materials is supported by a track system.
Start time – when each 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 strength will the screen become activated either to open up or close
Maximum/minimum temperature – what are the limitations of temperature desired
Maximum/minimum humidity – What are the limits of humidity desired
Gap positions – this models the percent open or close placement under different circumstances such as in early stages a winter early morning to lessen Rack Drive For Greenhouse thermal shock or through the summer to supply better shading. The gap measures and speed of movement can be controlled in a few systems.
Time delay – under changeable climate this avoids frequent starting and closing
Wind speed – To lessen high temperature loss, the screen can be closed early below high wind speed conditions
Snow detection – this can open the screen and turn on heat when it begins to snow.
The standard system uses nylon monofilament or stainless cables to aid the screen material. The screen material can either rest along with the network of cables or end up being suspended by hooks from the cables. A gearmotor powers a drum or rack and pinion that movements the leading edge of the screen materials. Control is usually either with a manual change or electronic controller.
Based on the over, the grower is required to enter the following parameters into the controller:
A weather station is required to provide outdoor light level, temperature, humidity, wind and rain or snow conditions.