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Always well wound – VariVent® winding ventilation

Discover the VariVent® winding ventilation from Lock, a revolutionary solution that offers you complete freedom in the ventilation of your rooms. With the option of opening from above, from below or a variable combination of both, the VariVent® winding ventilation sets new standards in terms of versatility.

The VariVent® winding ventilation systems are designed so that they can also be operated outdoors without any problems. Thanks to the unique forced synchronization of our TC system in conjunction with TST14 (patented), this form of winding ventilation operates collision-proof. Our bottom-opening winding systems are used especially in greenhouse construction.


Flexibility is very important to us - whether single or double wound, with drive at the end or in the middle, manually or electrically controlled: we offer you the customization options that meet your specific requirements.

The lightness of our systems

Our systems can easily be converted from manual operation to electric drive to give you even more comfort and efficiency. Fully automatic control via our LSR, based on temperature, wind and rain or digitally via our SBE farm management system, makes VariVent® winding ventilation a smart solution for any environment.

Winding standard DIN EN 17088

All winding systems meet the winding standard DIN EN 17088

Innovative technology

Our innovative technology ensures high operational reliability through the use of lightweight aluminum tubes with small diameters and drives with low rotation speeds.

One drive is enough

A single drive is sufficient for a building length of an impressive 100 meters with a maximum opening height of 4.5 meters.

Put your trust in Lock and experience the future of roller ventilation technology.

Bubble for roller ventilation Bubble for roller ventilation

Opening from above

The world's most popular top-opening changing system! Our systems, all patented under European patents 0982466 and 1388637, set standards in terms of efficiency and user-friendliness.

VariVent® TF traction cable: Thanks to the innovative compensation mechanism of the GKT telescopic coupling, our traction cable system does not require any tension on the tarpaulin and no annoying readjustment. A single drive enables the upper edge to be lowered and the bottom to be wound up synchronously at the same time - without the risk of collision and with effortless installation.

VariVent® TF central tube: Our top-opening winding system with central tube redefines efficiency. By eliminating corner rollers, friction is minimized and the system even allows gates to be bridged. With a single drive, the upper edge is lowered and wound up synchronously at the bottom - for maximum safety and minimal risk of collision. 

Opening from below:

Our bottom-opening winding systems are available with an innovative fixed drive or climbing drive as well as a special compensation mechanism. In addition to the short installation space for the BC variant, our focus is particularly on uncomplicated installation in order to offer you maximum efficiency and user-friendliness.

Our drive means that there is no weight load on the winding tube. This not only enables an optimal winding process, but also protects the fabric considerably. Our goal is to offer you not only first-class products, but also innovative solutions for your individual requirements.

Thanks to our bottom-opening winding systems with VariVent® BC/BF, you will not only experience the highest performance, but also a sustainable and material-friendly application. The simple installation makes our products an outstanding choice for a wide range of applications.

This form of wrap ventilation is used specifically in outdoor climate stables for pigs. Since the run should be shaded in summer, many farmers often resort to wrap systems that open from below. The reason for this is that pigs can also get sunburn. In the poultry sector, however, this type of wrap is used to darken the area.

As an alternative to a roller screen, our bottom-opening wrap-around ventilation can be used in plastic greenhouses. On warm days, excellent air circulation and thus a better climate can be achieved.

Variable opening from top and bottom:

Our systems are proud holders of European patents 0982466 and 1388637 and represent a unique, fully variable concept worldwide. 

The VariVent® TC offers you all the advantages of our proven VariVent® systems in one outstanding package. The complete variability of the system allows you to configure the system according to your individual needs. Regardless of whether you want to open the windows from above, open them from below, position them for optimal shading or pull them up in summer operation - VariVent® TC meets all these requirements. 

With two EWA drives, the system is able to move windows up to 100 meters long and 4.5 meters high - all with minimal installation space to leave more room for natural ventilation. The climbing drive and the special balancing mechanism ensure precise and reliable control. Whether you are looking for efficiency, flexibility or the latest technology - VariVent® TC sets new standards in the world of top and bottom opening winding systems.

VariVent® Twin – Innovation for your building ventilation!

Discover the groundbreaking technology of VariVent® Twin, a patented system that revolutionizes the performance of conventional VariVent systems. With European patent 3018284, US Patent 10,041,295 and CA Patent 2,911,590, we offer you a unique solution to significantly increase the insulation value by up to 60%.

​Our VariVent® Twin impresses with its innovative, double winding ventilation, which achieves an outstanding insulation effect through an insulating air cushion with a distance of around 5 cm between the tarpaulins. The winding shaft is moved with just a single electric or manual drive, enabling synchronous winding and unwinding without collision. A special highlight is the possibility of combining different tarpaulins to allow sufficient natural light into your building. Compared to insulated tarpaulins that let little or no light through, we offer the ideal solution for balanced lighting in your rooms.​

​VariVent® Twin scores not only with its efficiency, but also with its cost-effective operation. In contrast to systems with a fan that has to continuously push air into the tarpaulins and lets the tarpaulin fall down in the event of a power failure, we do not have any ongoing electricity costs. Care and maintenance are also uncomplicated. By rolling up the tarpaulins, they remain clean even after years and are protected from rodents. ​

​Our electric drives enable fully automatic control with our LSR ventilation controller, including wind and rain sensor for optimal comfort, or our SBE farm management system. VariVent® Twin is not only suitable for new buildings, but also enables the retrofitting of existing single-wound VariVent systems. Give your building an efficient and advanced ventilation solution - VariVent® Twin, the future of building ventilation!

EazyVent® – The inexpensive alternative

Our EazyVent® is patent pending worldwide. It is characterized by a unique top-opening ventilation and the pulling up of the wound fabric from bottom to top. A central shaft with a cable drum enables the upper edge of the fabric to be lowered or raised precisely. Specially designed cables run around the fabric and are wound up again on the cable drum. With an opening height of up to 3 meters, the EazyVent drive creates optimal conditions. This winding system is also characterized by the easy bridging of doors and gates.

Function and advantages at a glance: 

  • Ventilation from top to bottom for a pleasant room climate. 
  • Clear opening height of up to 3 meters for maximum flexibility. 
  • Summer position: Move the fabric upwards without additional drive. 
  • No height offset of the lower fabric edge for a harmonious overall picture. 
  • No force introduction into the winding shaft required, thanks to well thought-out design. 
  • A single drive is sufficient for maximum efficiency. 
  • Optional manual or electric drive for individual requirements. 
  • Interruptions to the system, such as a gate, are possible without any problem. 
  • Suitable for multi-layer tarpaulins for a wide range of applications. 

Rely on EazyVent® – the intelligent solution for perfect ventilation. Contact us today and discover the numerous possibilities offered by our innovative system. 

  • Specially developed and proven systems for over 20 years
  • Special balancing mechanism
  • Long service life
  • Possibility of automation
  • Large ventilation heights up to 4.50m
  • Lengths up to 200m
  • Top opening system provider ​
  • Stainless steel wire rope
  • Use of aluminium winding tube
  • Functional and reliable
  • Use of various films and fabrics, no specification of Lock, manufacturer-neutral
  • Temperature fluctuations have no influence, therefore consistent, very good winding results, safety in any climate worldwide
  • Always the right system for end users, buildings and plants & individually adapted to your greenhouse
  • Security is a top priority for us – our systems are always up to date
  • Time saving + always the best air quality for optimal animal welfare without having to think about it, increased efficiency
  • Fast air exchange for optimal plant growth
  • Reducing energy costs through insulation layer
  • Simplification and faster assembly