In smaller greenhouses, a manual program opened and closed by hand could be installed. These work simplest when the screen rack drive for greenhouse china material is backed by a monitor system.
Start time – when each morning will the display system start operation
Stop time – when in the afternoon will the display system stop operation
Light level – in what light strength will the screen end up being activated either to open up or close
Maximum/minimum temperature – what exactly are the limits of temperature desired
Maximum/minimum humidity – What are the limitations of humidity desired
Gap positions – this pieces the percent open or close placement under different conditions such as in early stages a winter morning to lessen thermal shock or during the summer to supply better shading. The gap guidelines and speed of motion can be controlled in some systems.
Time delay – below changeable weather conditions this avoids frequent starting and closing
Wind speed – To reduce heat loss, the screen can be closed early under high wind speed conditions
Snow detection – this may open the display screen and turn on the heat when it starts 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 moves the leading edge of the screen material. Control is certainly either with a manual change or electronic controller.
Based on the above, the grower is required to enter the next parameters in to the controller:
A weather station is needed to provide outdoor light level, temperature, humidity, wind and rain or snow conditions.