ValkTwinRail | Extensive ventilation capacity

The ValkTwinRail ventilation mechanism offers the same quality benefits as the ValkTrussRail system, including better climate control, uniform ventilation openings, perfect sealing, and the resulting energy cost savings. But the ValkTwinRail mechanism goes even further than that. 

Where the ventilation windows in the ValkTrussRail mechanism are arranged intermittently on either side of the ridge, the ValkTwinRail comes with continuous ventilation windows on both sides of the ridge. This means that the ValkTwinRail delivers greater ventilation capacity, which may be needed for various reasons. For example:

  • To boost the cooling capacity as needed for a certain type of crop
  • To obtain sufficient ventilation capacity in a greenhouse with smaller sections.
  • To compensate for possible ventilation capacity loss when using insect mesh.

The drive system

You can’t have functional ventilation windows without a drive system. Van der Valk Horti Systems produces reliable, reduced ValkDriveTubes to guarantee constant quality.

Galvanised Contiflo tube, prevents white rust. Available in two diameters: 27mm and 32 mm. Available in standard lengths. Easy to fix to any make rack. Reduced coupling with flange nut/flange bolt link.

You can’t have functional ventilation windows without a drive system. Van der Valk Horti Systems produces reliable drive shafts using a welding robot to guarantee constant quality.

Drive shafts supplied to measure for any motor and rack manufacturer. Straight-welded ridges and pinions for a motionless drive. Made of high-quality European steel.


The ValkTwinRail ventilation mechanism is calculated completely for each situation using the unique WinTop calculation program, which was developed in partnership with TNO, the Netherlands Organisation for Applied Scientific Research.

Based on various variables (the geometry of the roof, the maximum local wind load, the required opening angle, etc.), all factors that may affect the system’s reliability are calculated. Such factors include the required structural strength, clearance between the mechanism and the roof structure, and the position of the rail consoles and rack and pinions.

Read what our partners say about their experiences with our company and our systems.

We can, of course, tell you all about how great our product is, but we prefer to leave that to our partners, who have been using our systems for years. Read here what they think about the ValkTwinRail!

Customer testimonial

‘Thanks to the innovative essence and high-quality products of Van der Valk Horti Systems, we have been able to raise our game in providing our customers with the very best horticulture greenhouses.’

Maurice Kassenbouw

Customer testimonial

‘We promote the “Van der Valk” brand to our customers as a guarantee of the best quality.

Van der Valk’s company structure also matches that of Horconex. This is one of the reasons why we have been working together so well for years (family business, customer-driven, innovative, and reliable).’


Customer testimonial

We like working with Van der Valk Horti Systems. They believe in their product, they innovate, and any problems are solved in no time.

Luiten Greenhouses

Customer testimonial

The materials that Van der Valk Horti Systems supplies are of good quality. Deliveries are virtually always complete. In case of damage or when we need to act fast, it is very convenient that they have always numbered the parts ordered in advance. For us, they are a reliable partner to work with.

Saarlucon Gewächshausbau

Customer testimonial

Dalsem builds and relies on Van der Valk Horti Systems. It is with good reason that we at Dalsem have been procuring our screen materials and ventilation mechanisms from Van der Valk Horti Systems to our full satisfaction for so many years.


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