Indian-German retractable roof greenhouse helps growers overcome heat problems

A customized structure and the HS2 system will help an Indian company deal with harsh weather, especially during the summer.  

Peak temperatures in the summer are an issue that Indian growers have to deal with. In the very hot summer - which can last from April to August - the average temperature can vary from 25 to 45 degrees C . 

In order to deal with this, the company has worked with retractable roof systems earlier. For this specific project the German company Novavert and the Indian company Prospex helped them showing the possibilities and unique features of a customized structure and the HS2 system: a keder-based roof screen system helping growers have more control over their roof screens. 

The structure is designed, made and installed by Prospex, experts in retractable roof greenhouses. Even though they have great expertise in the international greenhouse erection and auxiliary systems like irrigation and water treatment, a project like this was quite a challenge. "The site is located about 160 km north of Delhi in a remote place", Ratheesh Nathamani with Prospex explains. Yet since the company has over 25 years of experience in water treatment projects, it ended up fine. 

The HS2 system is equipped with a white woven and coated film with pre-cut holes, according to the planned crop spacing as the structure is all horizontal. "The panels were pulled in from one side with a winch, which is the most user-friendly way", says Niclas Heescher with Novavert. The company developed the system and has taken care of many alike projects. "In this case the customer was looking for a very cost-effective solution without the need to collect rain water so it was agreed to work with PVC profiles instead of the regular aluminium extrusions." 

Constant height
There's much attention paid to achieving the ideal climatic circumstances. Due to the constant height of 5.5m this house offers a huge air volume and helps to reduce temperature stress on the plants that will soon move in. The side material has a higher reflection thanks to incorporated aluminum strips and seals all around so that cultivation is kept clean and wild animals are kept away. 

Niclas shows how the HS2 system retracts both ways 4+4m over the 8m span so a closing cycle in high speed mode takes less than two minutes, allowing the climate computer to react as quickly as required.

Sensors to monitor
"For the three acres it only takes two strong drives located in the center bay to power the entire roof system so very little wiring was required. However a number of sensors will monitor the conditions inside and outside." In addition the control system developed by Prospex offers full control .

As the center bay will be used as a driveway, the roof panels in this area are permanent. Thanks to the slim structural design by Prospex and the adapted HS2 system, there is a minimal permanent shadow in all other bays in the retracted position.