Slot ventilation is an excellent solution for achieving natural ventilation in residential and commercial buildings. The knowledge blog “Natural ventilation with slot ventilation” explains what slot ventilation is and why it is important for a healthy indoor climate. This blog discusses the application of slot ventilation in new construction and renovation projects, as well as the associated slot vents from Tilmar.
The main difference between new construction and renovation lies in the way the vent is installed. In new construction, ventilation is already considered during the design phase. Frames are prefabricated, with a slot mechanically milled into the frame or window timber. The ventilation grille is integrated into this slot. Recessed slot vents therefore provide a clean and almost invisible finish and seamlessly match the frame construction.
In renovation projects, frames are usually already installed and remain in place. Adding or improving ventilation is often customized work, where options for milling or adjustments may be limited. Surface-mounted slot vents make it possible to achieve natural window ventilation without fully modifying the frame. These vents are mounted on or against the frame, allowing ventilation to be added without major structural modifications.
Tilmar supplies slot vents for both new construction and renovation projects. Some vents are specifically developed for built-in application in new construction, while most are flexible and can be used in both new construction and renovation.
The following vents are primarily intended for use in new construction. They are integrated into the window frame structure and are usually included in the production of the frame, making them less suitable for application in existing frames.
The Fresh 101 is a recessed slot vent for installation in the top rails of window frames. The internal vent is placed in a milled slot and features a hinged front cover that allows for stepless adjustment. The position of the front cover is adjusted by moving it outward and sideways. The vent has a favorable airflow pattern because the incoming air is deflected.
On the outside, a flat plastic external grille is mounted, optionally combined with an aluminum rain canopy to prevent rain ingress. The closable internal vent with aluminum faceplate is also available separately for other combinations. To ensure proper airflow, it is recommended to clean the vent and slot every 2–3 years.
The external grille is available in two versions:
The Fresh 31F is a recessed slot vent made of ABS plastic. The vent is installed in a milled slot in window timber or in the top rail of the frame and is equipped with a flange that neatly seals the slot.
The complete slot vent consists of an internal and external grille, including a built-in insect filter. The internal grille features a control flap along its entire length, which can be adjusted steplessly using a slider at the front. On the outside, an external grille is mounted to prevent rain ingress and keep insects out. Periodic maintenance is also recommended for this vent to maintain optimal airflow.
The TiKu formed version is suitable for recessed installation, for example in wooden frames. The vent features folded edges for added strength and is finished in RAL 9010. Invisible mounting is possible on the outside, while the vent provides effective insect protection. Fixing is done with countersunk screws at the ends. The slot is milled using a 16 mm cutter, matching the fixed width of the vent.
The TiKu formed vent (700 mm) is particularly suitable for combination with the Fresh 101 internal vents. In addition, both TiKu models can be combined with SM1400 Rotary internal vents (500 and 700 mm). These are mainly applied from an aesthetic point of view: ‘invisible’ installation in the reveal of the frame, so that the façade appearance is not affected.
In addition to vents specifically developed for new construction, Tilmar offers various slot vents that can be applied in both new construction and renovation projects.
The SM1400 Rotary is an aluminum slot vent that can be adjusted steplessly using a horizontally rotating rotor cap. The internal vent can be fully sealed airtight and is equipped on the inside with a removable ABS plastic click filter, which is easy to remove and clean.
Thanks to its universal installation method, it can be applied in milled slots, interrupted slots, or drilled holes. An alternative application is to use only the internal vent, where the slot is milled at an angle and no visible external grille is required.
To open and close internal vents at greater heights, the SM1400 slot vent can be combined with a separate 1-meter aluminum SM1400 operating rod. The hook easily attaches to one side of the vent, allowing operation without installation. The rod is not permanently connected to the vent and is supplied as a separate accessory.
The flat TiKu version is designed for surface-mounted applications in a variety of situations. This version is available in multiple variants with differences in length, width, and slot pattern. The vent can easily be cut to size and is fixed using small mounting holes. This version is also standard available in RAL 9010.
The FlexiGrille is a multifunctional stainless steel flexible slot vent for situations where ventilation slots and expansion joints must remain open, while protection against dirt and small animals is desired. Many slots, both horizontal and vertical, are intended for structural ventilation and must therefore remain open. FlexiGrille offers an aesthetically sound solution for this, suitable for both integration in new construction designs and creative application in renovation projects.
The vent is installed by clamping the strong stainless steel spring profile into openings of 5 to 35 mm in height. Installation is possible in horizontal, vertical, and angled slots. The slot does not need to be perfectly straight; the vent adapts to irregularities, resulting in a clean and seamless appearance. The vent can easily be cut to size and, if desired, installed in reverse for a virtually invisible finish. For project applications, FlexiGrille is available in RAL colors on request.
Fresh plastic slot vents offer practical and budget-friendly solutions for natural window ventilation. The vents consist of an internal and external grille and are made of ABS plastic. Depending on the type, they are either closable or non-closable and can be applied as recessed or surface-mounted solutions. All Fresh slot vents are made of white ABS plastic and are designed for easy installation and use. In addition, the vents are equipped with an integrated filter that is easy to remove and clean. Regular maintenance of the vent and slot is recommended to ensure a consistently good airflow.
The Fresh 65 is a closable slot vent that can be used in both new construction and renovation, depending on the selected version. The complete set consists of an internal grille, external grille, and mounting block, and is finished in white.
For recessed installation over a milled slot, type A (with mounting block) is applicable. For installation over drilled holes—typically in renovation—type B (with mounting sleeve) is used. Internal and external grilles can also be ordered separately; a standalone internal grille is supplied as type A (with mounting block) by default. If a type B version is required, this must be specified separately.
The Fresh 32 and Fresh 42 are compact, closable slot vents with adjustable airflow in a smaller format than the Fresh 65. A complete vent consists of an internal and external grille with an integrated filter.
The internal grille features a control flap along its entire length, which can be adjusted steplessly using a slider at the front. The vent has a favorable airflow pattern because the incoming air is deflected at both the top and bottom. The main difference between these versions lies in airflow capacity and slot height, with the Fresh 32 having a lower airflow capacity than the Fresh 42.
The Fresh 10, 12, 13, 14 and 20 are non-closable transfer vents in a surface-mounted design. These vents consist of two or four separate components (internal and external) and differ in design, construction, and dimensions. They are used for simple ventilation needs where adjustability is not required and a functional, budget-friendly solution is sufficient.
For detailed product information, please refer to the corresponding product pages and technical sheets for the plastic slot vents.
The choice of a slot ventilator is determined by the phase of the project (new construction or renovation), the window frame construction, and the desired ventilation performance. Some ventilators are specifically designed for integration into prefabricated window frames, while others can be flexibly applied in a wide range of situations.
For detailed product information and possible combinations, please refer to the corresponding product pages and datasheets on the website.
Nederlands 
Deutsch 
Français 