Vaillant recoVAIR end piece 2× 75/62 mm to DN 125

Product detailed description

End piece 2 x 75/62 mm to DN 125 (Vaillant recoVAIR, code 0020176832)

The end piece 2 x 75/62 mm to DN 125 is an original transition and connecting part of the Vaillant recoVAIR ducting system, used to connect up to two separate branches of flexible hose with a diameter of 75/62 mm to one common valve connection with a diameter of DN 125 mm. This DN 125 mm connection is the standard interface used in the recoVAIR system to connect wall and ceiling outlets (both supply and extract), including design cover grilles. The end piece thus acts as a connecting link between the "last mile" of ducting run with thinner 75/62 mm hose (typically from a distributor or collector) and the outlet itself in the room, which for structural and aesthetic reasons has a larger diameter of 125 mm.

Position of the end piece in the overall recoVAIR system concept

The entire ductwork of the recoVAIR system can be divided into three basic sections: the main route with larger-diameter EPP ducting (210/180 mm or 180/150 mm) leading from the recoVAIR unit itself to the distributor or collector, the middle route with smaller-diameter 75/62 mm ducting leading from the distributor to individual rooms, and finally the end points at the outlets in individual rooms. The end piece 0020176832 belongs precisely to this third, terminal category and represents a transition from the thinner distribution ducting to the wider, standardized DN 125 mm connection, to which the visible outlet itself is connected. Understanding this three-stage concept helps with orientation within the entire recoVAIR accessories range and with correctly selecting the parts needed for a specific installation.

Why two hoses are joined into one connection

When designing controlled ventilation ductwork with heat recovery, it often proves advantageous to split the required air flow for one room (for example a larger living room or a combined living/kitchen space) into two separate, thinner branches instead of a single branch with a larger diameter. The reason is, on one hand, easier routing of two thinner hoses in a limited space in the suspended ceiling or within the thickness of the ceiling structure (where two hoses with a diameter of 75/62 mm can fit even where a single hose with a larger diameter would not), and on the other hand, better distribution of pressure losses between two parallel branches instead of one. It is precisely for joining such two parallel branches into one common outlet connection that this end piece with two 75/62 mm inlets and one DN 125 mm outlet is used.

Design and technical construction

The end piece has a body with two spigots with a diameter of 75/62 mm on one side (usually arranged at an angle, for example in a "90°" configuration, or in a straight line depending on the specific design version) and one circular connection with a diameter of DN 125 mm on the opposite side. Included in the delivery is a mounting plate (fixing plate) for anchoring the part into the structure of the ceiling, partition, or wall, as well as sealing rings on both inlet spigots and on the outlet connection, and protective caps used for temporarily sealing the connection against dust during construction work before the final connection of the outlet. This combination of two thinner inlets and one larger outlet makes the end piece essentially a small collector integrated directly at the outlet.

Installation and placement in the structure

The end piece is installed at the location where the outlet in the room is to be located – either in the ceiling (for ceiling outlets) or in the wall (for wall outlets). The mounting plate allows for firm anchoring of the part into the load-bearing structure (for example into an OSB board of a suspended ceiling, into a partition, or into ceiling formwork before pouring concrete, in the case of installation into a monolithic ceiling). Both hoses from the distributor side are slid onto the respective inlet spigots and secured with cable ties, while the DN 125 mm outlet connection remains ready for the final connection of the outlet – which is usually installed at a later stage of construction, after finishing the surface treatment of the ceiling or wall, in order to prevent it from becoming soiled or damaged during construction work. This is precisely why protective caps are supplied for the DN 125 mm connection – they prevent dust, mortar, or construction debris from entering the ducting during the period between the rough installation of the ductwork and the final installation of the outlets and floors.

Compatibility with outlets and grilles

The DN 125 mm outlet connection of this end piece is compatible with a whole range of Vaillant wall, ceiling, and floor outlets with the same interface, including standard and design cover grilles (for example the design outlet with a white finish, code 0020197693, also available in our range). Thanks to the uniform DN 125 mm interface, the customer can subsequently, or during renovation, choose a different type of cover grille (for example switching from a standard version to a design one) without needing to intervene in the ducting itself behind the ceiling or in the wall – it is enough to replace the visible cover part of the outlet.

Flow parameters and sizing

The combination of two 75/62 mm inlets leading into one DN 125 mm outlet is designed so that the sum of the flows from both branches does not exceed the capacity that a 125 mm diameter outlet can smoothly and quietly discharge into or from the room. The precise sizing (i.e. what combination of branch length, number of bends, and required flow can be connected to this end piece) is part of the ventilation design, which also takes into account the overall performance curve of the selected recoVAIR unit. In general, this two-inlet configuration is used for rooms with a higher required air exchange (for example living rooms, large bedrooms, or combined living spaces), where a single thinner 75/62 mm branch would require an excessively high flow velocity and the associated noise to achieve the required flow rate.

Why choose an original Vaillant part

This end piece is one of the structurally more complex parts in the 75/62 mm accessories range, as it must simultaneously guarantee the tightness of three joints (two inlets and one outlet), sufficient mechanical strength of the mounting plate for fixing into the building structure, and at the same time smooth, aerodynamically optimized internal flow that merges two air streams into one without excessive turbulence and noise. The original Vaillant part is specifically designed and tested by the manufacturer for this combination of functions as part of the entire recoVAIR system, which cannot be guaranteed with an improvised or universal solution.

Common installation mistakes

Common mistakes include insufficient fixing of the mounting plate into the structure, which can, during subsequent installation of the outlet (when slight pressure is applied to the DN 125 mm connection when inserting the cover grille), cause the entire end piece to loosen or shift within the ceiling structure. Another mistake is forgetting the protective caps on the DN 125 mm connection during rough construction work, which can lead to the ducting becoming clogged with dust or construction debris, which is subsequently difficult to remove without dismantling part of the ductwork. We therefore recommend leaving the caps in place until the area around the outlet is finally completed and ready for installation of the cover grille.

Maintenance

After the outlet installation is completed, the end piece requires only minimal maintenance – occasional inspection of the sealing rings on the inlet and outlet connections during regular filter replacement of the recoVAIR unit. Since this is a part hidden within the ceiling or wall structure, direct inspection is only possible through an inspection opening or by removing the outlet's cover grille – if a leak is suspected (for example if there is a drop in air flow at the given outlet compared to the designed value), we recommend having the inspection carried out by a service technician.

Frequently Asked Questions (FAQ)

Difference between the angled and straight version of the end piece

Vaillant offers this end piece with two 75/62 mm inlets and a DN 125 mm outlet both in a straight version (where the outlet connection is in line with the body of the part, suitable for installation directly above or below the outlet in a horizontal ceiling), and in an angled 90° version (as offered by this product), which is more suitable where the ducting runs horizontally along the ceiling and the outlet is positioned on its surface facing straight down, or in the case of a wall outlet, horizontally from the side. The choice between the two variants depends on the specific layout of the given room and on the direction in which the main ductwork is routed to the given end point – the ventilation designer will therefore determine, when preparing the design, which of the two variants is more suitable for a particular location.

Condensate drainage in extract branches

In extract (exhaust) branches of the ductwork, i.e. where contaminated air is extracted from the room towards the recoVAIR unit, slight condensation of water vapour may occur on the inner surface of the ducting during colder months, especially in sections routed through unheated spaces. For this reason, the recoVAIR system, in some configurations, also includes a separate drainage element (a dry siphon) at the unit, which collects any condensate from the entire extract ductwork. The end piece at the outlet itself is not designed to collect condensate, but its tight and correctly directed connection (without a local dip where water could accumulate) helps ensure that any condensate flows smoothly towards the unit, where it is collected in the prescribed manner.

Aesthetic and practical aspects when choosing the installation position

Since the end piece determines the exact position of the future outlet in the room, its placement needs to be carefully planned already during the rough installation of the ductwork, in line with the future arrangement of furniture, light fixtures, and other interior elements. Subsequently changing the position of the outlet after the ceiling or wall has been finished is usually significantly more complicated and costly than planning it correctly in advance, so we recommend thoroughly coordinating the position of all outlets with an architect or interior designer before installing the ductwork, especially in the case of visible ceiling outlets in representative rooms.

Who this product is intended for

The end piece 0020176832 is intended primarily for installation companies carrying out controlled ventilation ductwork with heat recovery in new buildings, where the design provides for connecting two thinner branches to one outlet in a larger or combined room. It is also suitable for service organizations during renovations or modifications of existing ductwork, where the number or routing of branches leading to a given outlet is changed. Given the technical complexity of correct sizing (sum of flows, placement within the structure, choice of a suitable outlet), we recommend always consulting the installation with a ventilation designer.

Material and mechanical resistance

The body of the end piece is made of durable plastic with sufficient wall thickness to withstand the mechanical stress of inserting the outlet's cover grille as well as any slight stress on the ceiling structure during the settling of a new building in the first years after completion. The mounting plate is sized to hold the weight of the entire part, including connected hoses and any outlet, without the need for additional support, provided it is correctly anchored into the load-bearing structure with screws suitable for the given type of substrate (plasterboard, OSB board, masonry, or wooden roof structure).

Summary and package contents

The package contains one end piece with two 75/62 mm inlets and one DN 125 mm outlet, including a mounting plate, sealing rings on all connections, and protective caps for the outlet connection. This is an original part directly from the manufacturer Vaillant, intended for connecting a controlled ventilation outlet with heat recovery in the recoVAIR system to two separate ductwork branches. When ordering, we recommend taking into account the exact number of outlets with a dual connection according to the ventilation design and choosing the correct version (angled or straight) according to the specific layout of the given room, in order to avoid additional adjustments directly on site.