Chapter 3

Greenhouse Curtain Systems

Controlling Greenhouse Light Pollution

The use of artificial lighting has become a widespread practice in the greenhouse sector. Artificial lighting significantly boosts greenhouse plant productivity by extending the times where photosynthesis can occur and by providing greenhouse operators with more control over the various stages of plant life cycle. In short, artificial lighting allows greenhouse operators to boost productivity. Throughout this time, lighting technologies have also progressed significantly. For example, modern light emitting diode (LED) lighting technology is more energy efficient than older lighting technologies and allows greenhouse operators to vary the light spectrum and light intensity based the specific stages of plant growth, further enhancing productivity.

Light-Emission Curtain Configurations

Ceiling light abatement curtains span the gap between the walls above the crop production area. They act as a semi-permeable barrier between the lower portion of the greenhouse and the attic. Some light abatement curtains are specifically designed for sidewalls and end walls of greenhouses.

Installation

When light abatement curtains are being installed in a greenhouse, they may have additional features like fastening strips, zippers or magnetic closures to minimize light leakage from gaps. They may be layered on top of other curtains to provide greater versatility according to the needs of the producer. Light abatement curtains are typically installed with an automated deployment system that is controlled by the greenhouse environment management computer system.

Sidewall Curtain Systems

Sidewall curtains are used to form interior partitions, to cover walls in blackout systems, to shade south-facing walls, and to cover and uncover sidewall vent openings in place of a glazed vent or louvers (Figure 3.10). Ground-to-ground systems use a single panel of fabric that extends up the walls from the ground on one side of the greenhouse, across the top, and down the walls to the ground on the opposite side of the greenhouse.

Drive Systems

Three common drive systems are used to raise and lower side wall curtains. In one system the curtain material is wrapped around a tube and the wall is raised and lowered by rolling and unrolling the material from the tube. The tube can be driven with a hand crank or with an electric motor and gearbox.

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