In smaller greenhouses, a manual program opened and closed by hand could be installed. These work easiest when the screen material is supported by a monitor system.
Start time – when in the morning will the display screen system start operation
Stop time – when in the afternoon will the display screen system stop operation
Light level – at what light intensity will the screen be activated either to open or close
Maximum/minimum temperature – what are the limits of temperature desired
Maximum/minimum Motor Gearboxes For Greenhouse humidity – What are the limitations of humidity desired
Gap positions – this units the percent open up or close placement under different circumstances such as in early stages a winter morning to reduce thermal shock or through the summer to supply better shading. The gap techniques and speed of movement can be controlled in a few systems.
Time delay – below changeable climate this avoids frequent opening and closing
Wind speed – To lessen high temperature loss, the screen can be closed early below high wind speed conditions
Snow detection – this may open the display and turn on the heat when it starts to snow.
The standard system uses nylon monofilament or stainless steel cables to support the screen material. The screen material can possibly rest on top of the network of cables or be suspended by hooks from the cables. A gearmotor powers a drum or rack and pinion that techniques the leading edge of the screen material. Control is usually either with a manual change or electronic controller.
Based on the over, 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.