Vaillant recoVAIR EPP elbow 90° 210/180 mm

Product detailed description

EPP 90° elbow Vaillant recoVAIR 210/180 mm is a fitting designed to change the direction of the air ducting by a right angle in mechanical ventilation systems with heat recovery recoVAIR VAR. Just like the straight duct sections, this elbow is also made of expanded polypropylene (EPP) with a flat oval cross-section of 210 x 180 mm and forms an integral part of the original accessory system needed for almost every real-world duct route, since the ducting rarely runs from the unit to the facade or manifold in a completely straight line without a single change of direction.

Function of the elbow in the duct route

In every building, the ventilation ducting is forced to bypass load-bearing structures, chimneys, other utilities (electrical wiring, sewage, heating) or change direction when passing between rooms and technical spaces. The 90° elbow allows this change of direction to be carried out in a controlled, structurally verified way with minimized pressure loss compared to improvised bending of straight ducting, which is not even possible with this material anyway - EPP ducting cannot be bent, a dedicated fitting such as this elbow is always required for a change of direction.

The internal shape of the elbow is designed so that the airflow remains as smooth as possible during the change of direction, preventing excessive turbulence that would otherwise increase operating noise and pressure loss on the given duct branch - this is one of the reasons why, when designing the route, it is always recommended to minimize the total number of elbows on a given branch, even though the elbow itself is structurally optimized for low resistance.

Technical features

• Material: expanded polypropylene (EPP), the same as used in the straight duct sections - ensures identical thermal insulation and mechanical properties throughout the entire duct route.
• Cross-section: 210 x 180 mm, identical to the straight ducting, couplings, T-pieces and other parts of this accessory family.
• Angle of direction change: 90° (right angle) - the most commonly used change of direction when routing ducting along walls, ceilings and structural elements of the building.
• Connection ends: shaped on both sides for sliding onto straight ducting or connecting to an adjacent fitting.
• Weight: thanks to the foam structure of the material, significantly lower than a comparable metal elbow, which makes overhead installation easier for the installer.

Installing the elbow into the ducting

1. Determine the exact location of the change of direction according to the project documentation or the actual spatial conditions on site.
2. Connect the elbow to the adjacent straight EPP ducting sections on both sides, or directly to another fitting (for example, to the end of the ducting coming out of the recoVAIR unit).
3. Check the orientation of the elbow so that the direction of change matches the actually required direction of the route (the elbow can be rotated 180° if needed for a mirrored change of direction).
4. Secure the joints on both sides of the elbow so that they are airtight and mechanically stable, especially if the elbow is located at a point where it will subsequently bear the weight of the adjacent ducting.
5. If the elbow is located in the middle of a longer duct section, it is recommended to add support with a mounting bracket immediately before and after the elbow to prevent excessive mechanical stress on the joints at this point.

Minimizing the number of elbows when designing the route

Every elbow in the duct route, even though aerodynamically optimized, represents a point of increased pressure loss compared to a straight section of the same length. A higher total number of elbows on one duct branch therefore means that the recoVAIR unit's fan must work at a higher output to achieve the same airflow, which results in higher operating noise and slightly higher electricity consumption. When designing the route, it is therefore recommended to:

• choose a route with as few changes of direction as possible, even at the cost of a slightly longer total length of straight sections,
• avoid two elbows placed directly one after another without a straight intermediate piece of ducting, if the building's structure allows it,
• and, if several changes of direction are unavoidable within a short section, consult with the ventilation designer whether that duct branch requires a more powerful recoVAIR unit model to compensate for the higher pressure loss.

Compatibility

The elbow is fully compatible with the entire family of Vaillant recoVAIR components in the 210/180 mm cross-section - straight ducting (both 500 and 1000 mm), couplings, T-pieces, the connection adaptor to the manifold/collector, facade grilles and the noise silencer. It is intended for use with the whole range of recoVAIR VAR 60/4, 150/4, 260/4 and 360/4 units wherever the project specifies this cross-section of ducting.

Effect of the number of elbows on choosing the right unit model

For projects with a more complicated house layout, where a higher number of changes of direction is necessary on individual duct branches, it is worth consulting with the designer already at the stage of selecting the recoVAIR unit whether the model under consideration (60/4, 150/4, 260/4 or 360/4) has sufficient fan power reserve to cover the higher total pressure loss caused by a greater number of elbows and other fittings on the route. More powerful models in the recoVAIR VAR range are generally better dimensioned for more branched and longer routes with a higher number of direction changes, while for simpler, more compact layouts even the basic model in the range is sufficient.

Maintenance

The elbow, like other hidden ducting components, does not require active maintenance during operation. During regular servicing of the ventilation system, it is recommended to visually check the accessible joints of the elbow with the adjacent ducting for any loosening or mechanical damage that could cause a leak and the associated drop in performance or increase in noise of the system.

Checking tightness after installing the elbow

After installing the elbow into the duct route, it is advisable to perform a simple tightness check of the joints on both sides of the fitting before covering the ceiling or closing the installation shaft:

• Visually check that the elbow is inserted into the adjacent ducting or fitting on both ends to a sufficient overlap depth, as specified by the manufacturer's installation instructions.
• After starting the recoVAIR unit in trial operation, you can place your hand near the joint to feel for any air leakage that would indicate a loose connection.
• In professional installations, pressure measurement in the system before and after covering the ducting is sometimes used, which can reveal even minor leaks not visible to the naked eye.
• Any leaks found must be fixed before the ducting is finally covered by the building structure, since accessing hidden ducting after the construction is completed is significantly more complicated and costly.

Storage and transport of the elbow before installation

Despite its rigidity, the fitting is made of lightweight foam material, so it is recommended to handle it carefully during transport and storage on site, protect it from mechanical damage by sharp objects, and avoid placing heavier building materials on it, which could cause permanent deformation of the elbow's shape before it is installed into the ducting.

Why choose an original Vaillant part

The precise shape and dimensional match of the elbow with the other components of the recoVAIR system ensure that the change of direction of the ducting occurs with minimal pressure loss and without leaks that could arise when combining it with a non-original fitting from another manufacturer, where even a visually similar part may not exactly match the tolerance and profile of the original Vaillant EPP ducting.

Typical places of use for the elbow in a family house project

In a typical family house project with a recoVAIR ventilation unit installation, the 90° elbow most commonly appears in the following places along the duct route:

• Unit outlet - the recoVAIR unit's connection ports are usually oriented horizontally or vertically depending on the installation method (wall-mounted, ceiling-mounted), while the duct route often continues in a different direction - the elbow ensures a smooth transition between the unit's orientation and the direction of the main route.
• Transition from the utility room to the ceiling void - when routing the ducting from a vertical position (for example, from a unit mounted against the wall) to a horizontal route in the ceiling void, one or two elbows are needed to change direction from vertical to horizontal.
• Bypassing structural elements - ceiling beams, girders, chimney structures or other utilities (electrical wiring, sewage) may require a change of direction in the duct route to avoid them.
• Connection to the facade grille - if the unit is not located directly next to the perimeter wall, an elbow is often needed before connecting to the facade grille to direct a short section of ducting perpendicular to the facade.
• Branches to the manifold or collector - when splitting the main branch into individual rooms, elbows are used to direct the individual branches toward the respective rooms according to the house's floor plan.

Difference between an elbow and a T-piece

It is important not to confuse the 90° elbow with a connecting T-piece, even though both components change the direction of airflow. The elbow serves exclusively to change the direction of a single airflow without splitting it - air enters from one side and exits in an unchanged quantity in a new direction on the other side. A T-piece, on the other hand, splits (or, conversely, joins) the airflow into two separate branches, which is used when branching the ducting to multiple rooms. So if a project only requires a change of direction without splitting the flow, this elbow is the correct component, while a separate T-piece is needed when splitting the route into two branches.

Effect of the elbow's orientation on the acoustics of the system

Experience from ventilation ducting installations shows that a point where the airflow changes direction can be a source of slightly increased noise, especially at higher airflow speeds. For this reason, in more sensitive rooms (bedrooms, children's rooms), it is recommended to:

• position elbows at a sufficient distance from the final outlets in the room, so that any noise generated by the change of direction has time to be partially dampened by the ducting itself before entering the room,
• avoid combining an elbow directly before or after a noise silencer in a way that could reduce the effectiveness of the silencing - it is recommended to leave a short straight section of ducting between the elbow and the silencer, if the space allows it,
• and when designing, take into account that the sum of multiple elbows on one branch has a cumulative effect on the total noise level and pressure loss of that duct branch.

Material and dimensional match with other components

The elbow is made of the same expanded polypropylene as the straight duct sections, couplings and T-pieces in this accessory family, which ensures that the thermal insulation properties remain consistent throughout the entire duct route, including points where the direction changes. The precise match of the outer and inner dimensions of the connection ends with other components of the recoVAIR system also guarantees that the joint between the elbow and the adjacent ducting or other fitting remains airtight without the need for additional sealing.

Summary

The EPP 90° elbow Vaillant recoVAIR 210/180 mm is an essential fitting for changing the direction of air ducting in mechanical ventilation systems with heat recovery recoVAIR VAR. Its design optimized for smooth airflow, low weight and full compatibility with other EPP ducting components make it a reliable choice for installers and investors who want to achieve quiet, energy-efficient operation of the ventilation system even on routes with unavoidable changes of direction. When designing and carrying out the installation, we always recommend ordering a sufficient reserve of elbows already at the material ordering stage, so that any adjustment of the route directly on site (for example, due to an unexpected obstacle in the structure) does not require halting installation to order the missing part.