Two types of operating system are available for horizontal roof screens. The Push-Pull system using rack & pinions, or the Pullwire system using torque tubes. Both systems can be used for single, double or even triple screen installations. With high energy costs, and critical control of the growing environment required, growers are increasingly installing double screens; one energy screen, and the other a shade screen.
With recent technical advances, modern pullwire systems offer advantages for larger greenhouses. The new Ultra-Delay slip blocks, combined with the Ultra-Lock profiles developed by Alweco ensure perfect closure for every screen installation.
The precision that this system allows makes it ideal for use with blackout screens, ensuring that it is truly dark!