Vaillant flexible air duct ø75/62 mm, 40 m - recoVAIR /4

Product detailed description

Vaillant flexible air duct Ø75/62 mm, 40 m - recoVAIR /4

The flexible air duct with a diameter of 75/62 mm is the end distribution branch of the Vaillant recoVAIR /4 system, which supplies air from the low-profile (or classic) manifold to specific end elements in individual rooms - diffusers, disc valves or wall/ceiling outlets. The duct is supplied in a practical 40-metre roll, from which the exact length needed for a given branch of the distribution system is cut during installation, so a single roll typically covers several shorter branches within one family house project.

This is a grey, flexible duct made of polypropylene (PP), characterised by a very smooth inner surface that facilitates air flow and any subsequent cleaning, as well as an antistatic treatment that limits dust build-up on the inner surface of the duct. The package also includes sealing caps for both ends of the roll, which protect the inside of the duct from contamination during storage and transport prior to installation.

Technical characteristics

• Diameter: Ø75/62 mm (outer/inner diameter)
• Package length: 40 m in one roll
• Material: polypropylene (PP)
• Colour: grey
• Surface: smooth inner surface, facilitating air flow and cleaning
• Antistatic treatment - limits dust build-up on the inner surface
• Non-insulated design (without a thermal insulation jacket)
• Included in the package: sealing caps on both ends of the roll for dust-free storage
• Flexibility allowing the duct to be routed in tight and complex ceiling void spaces
• Compatible with units: recoVAIR VAR 150/4 L, VAR 150/4 R, VAR 260/4, VAR 260/4 E, VAR 360/4, VAR 360/4 E
• Country of origin: Germany (production plant of the Vaillant Group)
• Warranty: 2 years from sale to the end customer

Use in the recoVAIR /4 system

The flexible 75/62 mm duct represents the last, most intricate part of the air distribution - leading from the distribution manifold (12-outlet or 17-outlet) to the specific end element in a given room. Thanks to its flexibility, it allows the route to be led around beams, installations and other obstacles in the ceiling void without the need to use many rigid fittings (elbows, branches), which in practice significantly simplifies and speeds up installation, especially in more complex or tight ceiling spaces.

Each branch of this duct is connected at one end to a manifold outlet (directly or via an adapter) and at the other end to the end element in the room, usually also via an adapter with a bayonet lock for quick and tight installation without the need for additional sealing or gluing.

Installation - procedure and recommendations

1. Measure the actual required length of the branch directly on site (from the manifold outlet to the position of the end element in the room), with a reasonable allowance for going around obstacles in the ceiling void.
2. Cut the required length from the 40-metre roll with a sharp knife, perpendicular to the axis of the duct, so that the end is straight and suitable for fitting the adapter.
3. Fit the appropriate adapters (of the same 75/62 mm diameter) to both ends and connect them to the manifold outlet on one side and to the end element in the room on the other side.
4. When routing the duct in the ceiling void, avoid sharp kinks that could narrow the passage diameter and increase the pressure loss of the given branch - route the duct with the smoothest possible bends.
5. Secure the duct against sagging with suitable clips/brackets at regular intervals so that it does not deform or drop to a lower position in the ceiling void over time.
6. Before covering with the ceiling, we recommend checking the tightness of all joints at both ends of each branch.

Why a non-insulated design and when to consider additional insulation

This flexible duct is supplied in a non-insulated design, as it is primarily intended for routing within the heated or at least tempered space of the building (typically the ceiling void beneath the heated rooms), where there is no significant temperature difference between the air in the duct and its surroundings, and therefore no risk of condensation. If a project requires this duct to be routed through an unheated or significantly colder space (e.g. an uninsulated attic), we recommend consulting a ventilation designer regarding the need for additional thermal insulation of the given branch, since, unlike the main EPP route, the duct itself has no inherent thermal insulation function.

Compatibility with the recoVAIR /4 system

The 75/62 mm diameter duct is the standard diameter for end branches throughout the Vaillant recoVAIR /4 system and is designed for direct connection to:

• outlets of the low-profile manifold (both the 12-outlet and 17-outlet variants),
• direct adapters of the same diameter for connecting to wall/ceiling end elements,
• other connecting and reducing elements of the same diameter in the recoVAIR /4 accessories range.

Do not combine this duct with end elements or adapters of other diameters without using a suitable reducer recommended by the manufacturer, to avoid a leaky joint or an unwanted change in the pressure loss of the given branch.

Flow characteristics and branch sizing

The 75/62 mm diameter in the recoVAIR /4 system is sized for standard air flows corresponding to one ventilated room of standard size in a family house. When designing the length and routing of individual branches, we recommend taking into account that:

• longer branches represent a higher resistance to air flow (higher pressure loss) than shorter branches of the same diameter,
• every sharp kink or elbow in the duct route increases the total pressure loss of the given branch,
• significantly different lengths of individual branches within one manifold can make it harder to balance the flows between rooms evenly.

The precise sizing of the length and number of elbows on individual branches is part of the ventilation design project, which takes into account the performance parameters of the chosen recoVAIR /4 central unit as well as the floor plan of the specific building.

Why flexible duct instead of rigid fittings for end branches

While the main route of the recoVAIR /4 system uses rigid EPP ducting with precisely defined fittings (elbows, branches), flexible duct has clearly become the preferred solution in practice for the end branches to individual rooms, for several practical reasons:

• Adaptation to the actual route in the ceiling void - while the main route is usually straight and easy to plan already at the design stage, the end branches often have to go around beams, electrical wiring, ducts of other trades and other obstacles that only become apparent directly on site.
• Faster installation - the installer does not need a separate fitting (elbow) for every change of direction in the route, but simply bends the flexible duct into the required shape, which significantly shortens the installation time for a larger number of branches.
• Fewer joints - every joint in the distribution system is a potential leak point; flexible duct allows even a more complex route to be led with a minimum number of joints compared to a rigid solution made up of many shorter fittings.
• Easier subsequent adjustments - if the position of the end element in a room later changes (e.g. relocation of a light fixture or furniture during finishing works), it is easier to adjust the route of a flexible duct than to rebuild an assembly of rigid fittings.

Acoustic comfort and air flow

The smooth inner surface of this duct is not only a matter of easier cleaning, but above all of acoustic comfort and energy efficiency of the whole system. A rougher or corrugated inner surface of the duct (typical of some cheaper alternatives with a strongly corrugated inner profile) increases the resistance to air flow, which requires higher fan power from the central unit to achieve the same flow rate - and higher fan power directly translates into higher operating noise of the system, which occupants notice especially during quiet night hours. The smooth surface of this duct therefore contributes both to lower operating electricity consumption of the fans and to overall quieter and more comfortable operation of the controlled ventilation system.

Practical tips for efficient use of the 40-metre roll

• Before cutting, prepare a list of all required lengths of individual branches based on the project documentation, in order to make optimal use of the entire length of the roll with minimum waste.
• When cutting, proceed from the longest required sections to the shortest, which makes it easier to efficiently divide the remaining material into shorter branches.
• Keep the remaining shorter offcuts - they can come in handy as spare material for a future repair or adjustment of one of the shorter branches.

Maintenance and care

Once installed in the ceiling void, the flexible duct does not require direct maintenance, as it is protected from coarse dirt by the central unit's filters. We recommend:

• checking the overall condition of the accessible parts of the ductwork whenever the central unit's filters are regularly replaced (usually 1-2 times a year according to the manufacturer's recommendation),
• taking care not to mechanically damage or pinch any of the duct branches during any work in the ceiling void (e.g. electrical wiring, lighting),
• considering a professional inspection of the relevant branch of the ductwork if reduced air quality or an unusual odour is suspected in a particular room, since the smooth antistatic surface of this duct significantly reduces, but does not completely eliminate, long-term dirt build-up.

Why choose a genuine Vaillant part

The quality of the flexible duct directly affects the resulting acoustic comfort and energy efficiency of the whole system - the smooth inner surface reduces pressure losses (and therefore the required fan power and noise), while the antistatic treatment limits long-term dust build-up inside the duct. A genuine Vaillant part guarantees an exact diameter match with all related components of the recoVAIR /4 system (manifolds, adapters, end elements), as well as the declared material properties important for the long-term hygienic operation of the ductwork.

Frequently Asked Questions

Comparison with alternative end-branch solutions

In the market for controlled ventilation accessories, besides smooth flexible duct with antistatic treatment, cheaper corrugated hoses are also common, as well as rigid plastic or galvanised ductwork made up of individual fittings. Corrugated hoses are generally cheaper and even more flexible, but their corrugated inner surface significantly increases pressure loss and air flow noise, and dust and dirt also settle more easily in the folds of the corrugated profile, which is not an optimal solution in terms of long-term hygiene of the ductwork. Rigid ductwork made of fittings, on the other hand, places higher demands on the accuracy of route design, and installation takes considerably longer, since every change of direction has to be handled with a separate fitting. The smooth flexible duct of the Vaillant recoVAIR /4 system therefore represents a balanced compromise between the ease of installation of a flexible hose and low pressure loss comparable to rigid smooth ducting.

Related products from the recoVAIR /4 range

Customers most often also purchase a low-profile or classic manifold (12-outlet or 17-outlet variant), direct adapters for connecting to the manifold outlets, or plugs for sealing off unused outlets together with this flexible duct. When planning a larger installation, we recommend ordering all these components at once, so that you have the complete ductwork assembly available before starting installation in the ceiling void, thus avoiding delays due to missing small connecting materials.

Additional Frequently Asked Questions

Delivery and packaging

Due to the length and volume of the 40-metre roll, this product is shipped by courier directly to your address, not via parcel lockers/pick-up points.