Greenhouse Blackout Screen, Photoperiod Control, Light Abatement, Energy Saving Screen

HI-99C W/B blackout screen has a blackout ratio of 99.9% which can prevent daylight from entering the greenhouse. This artificially shortens the length of the day and allows products such as chrysanthemums, gerberas, kalanchoas and medicinal crops to be produced all year round. HI-99C W/B is a blackout screen with upper side black and lower side white, typically two or three layers are installed horizontally on top of greenhouse to reach a perfect blackout effection. 

The upper side of the screen helps reflect sunlight, preventing heat buildup if the screen needs to be used during daylight hours. The screen's lower side is white, to reflect the light from the lamps back towards the crop, increasing the light intensity within the greenhouse. This three-to-five-percent increase in light can positively impact crop growth and yield. The closed structure of the screen provides greenhouse energy savings by retaining the heated air beneath it.

There are other blackout screens as well. The HI-99C B/B , a blackout screen with one side white and one side black, and the HI-99C A/B , a blackout screen with one side reflective aluminum and one side black. Usually one of those two types will use together with HI-99C W/B.  

Choosing an aluminum upper side retains most heat, while white is better for cooling. And for the underside, choosing white will intensify the effects of supplemental lighting. Their unique knitted structure reduces condensation and allows them to be bundled to a small size for maximum available light.  These moisture-regulating properties enable you to maintain the ideal temperature and climate in the greenhouse.

Blackout screens that are specifically designed for light-abatement purposes should be installed as an additional layer to any existing shade or energy-saving curtain, on a separate set of wires, and be moved by its own motor. Control through the greenhouse climate computer is also typically independent of other screens.

Double-layer blackout screens meant for photoperiod control can also be closed after dark for light abatement purposes. For example, HI-99C B/B+W/B, greater energy savings are most often realized with a multilayer screen. This may be necessary if, for example, the greenhouse range is used for both the vegetative and flowering stages of a cannabis crop. When a multi-layer blackout screen is used for light pollution abatement, more active management by the grower is often required to alleviate heat and humidity buildup under the screen.

** For technical datasheet please send enquiry to sales@jh-hortitech.com and contact our sales team.