Modern construction industry puts a lot of emphasis on the energy-saving properties of the building. Well-insulated buildings require constant air exchange to protect the interiors from dampness. In such conditions, a natural ventilation system is not enough. In order to protect the home against moisture and mould as well as enjoy the fresh air at all times, it is required to use a mechanical ventilation system with a heat recovery unit
Caring about the convenience of installing the ventilation and heat recovery units, Alnor expanded its offer to include the FLX-REKU system.
FLX-REKU system consists of ventilation non-metallic, semi-rigid ducts, plenum and distribution boxes, and other components that make for a full installation which may be connected to the heat recovery unit.
Semi-rigid FLX ducts are made of high-impact polyethylene in two versions - FLX-HDPE-75 standard version and FLX-HDPE-A-75 fitted with anibacterial layer. They are used whenever flexibility and durability are important - owing to their high diametral stiffness, the ducts may be covered with concrete.
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FLX-HDPE semi-rigid ducting, available in diameter 63, 75 and 90 mm
The antibacterial coating used in the FLX-HDPE-A-75 ducts prevents the growth of microorganisms, amongst all it protects the ducts from bacteria – Escherichia coli (ATCC 11229), Staphylococcus ureus (ATCC 6538). The test was performed by the Institute of Biopolymers and Chemical, according to PN-EN ISO 22196:2011 Plastics – Measurment of antibacterial activity on plastics and other non-porous surface. HERE check the Report.
Plenum boxes complement the entire system. They may be used both in intake and offtake ducts. They are fitted with an air flow guides which reduce obstructions in the air flow. Plenum boxes, as a standard, are made of galvanized steel, but may also be made of stainless 1.4301 sheets. They are very compact and low height means they can fit in the space between the layers of ceiling.
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FLX-PRO-75-3-5-3 Plenum boxes
Distributors complement the plenum box selection. Components with more connection points are excellent for buildings in which the ventilation system can only be lead from a single point. Distributors are made of galvanized steel.
FLX-REKU system is complemented by dampers, connectors, washers, end stops, elbows and T-sections.
Alnor product offer includes FLX-DAS and FLX-DAT dampers with an EPDM washer. FLX-DAS dampers are used wherever a tight seal is not required. Their main function is to adjust the air flow. FLX-DAT dampers are used wherever a tight seal is required. Their main function is to shut off the air flow. Damper adjustment angle range is 90o. FLX dampers are made of galvanized steel.
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FLX-DAT and FLX-DAS dampers
Plastic end stops are used to shut off stub pipes and unfinished ducts.
Washers to be installed at the connection points between ducts and fittings serve as an additional leak protection.
Heat shrink connectors are used to connect ducts.
Washers to be installed at the connection points between ducts and fittings serve as an additional leak protection.
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CS-PVC end stop and FLX-USZ-75 washers
Heat shrink connectors are used to connect ducts.
Bends are used whenever a sharp arc is required right next to the floor, where bending the duct section would not be possible.
The recuperator is connected with the duct by means of galvanized steel connectors.
At the end of the duct, linear air inlets with matching plenum boxes are used.
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LDS 4-slot linear diffusers
There are several arguments in favor of the FLX-REKU system. Owing to the small size and proper construction, FLX ducts may be installed on roofs, walls and floors. They may be covered with wet and dry plaster finish. The use of highly durable materials, resistant to mechanical damage, allows to place the installation under concrete leveling or in roof ceilings.Flat plenum boxes do not take up a lot of space, which means it is not required to make special structural components for floors or ceilings.
The FLX-REKU system uses a low number of components to make a ventilation system that is tailored to your individual requirements. System installation does not require special tools. Components are latched together, special washers allow for exact fit with a perfect seal.
Flexible duct structure allows to lead the installation along the shortest possible route. Smooth internal coating of the FLX ducts, minimum number of connectors and fittings as well as slight bending of the distributed ducts allow to reduce air flow and limit pressure loss inside the installation.
Antistatic and antibacterial coating inside the duct guarantees very good installation hygiene. Since there are no protruding screws used during the installation, it is possible to clean the system easily and thoroughly.
It is possible to achieve higher class insulation with FLX-Reku – however, this requires to use special seal for plenum boxes and to use the new washer type for FLX-HDPE ducts.
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Insulation measuring report for FLX-REKU
Insulation testing conducted by Alnor clearly indicates that the air loss for FLX-RECU ducts is less than required for insulation class C as per the PN-EN 12237 standard “Building ventilation -- duct network -- the durability and tightness of circular metal sheet ducts”.
It is worth to point out that the installation was built with the number of connections stipulated by the standard, which also applies for SPIRO ducts with standard 3-meter length. FLX-HDPE ducts are supplied in 50-meter sections – for this reason they are most often connected to plenum boxes only, which means the number of connections can be less by a dozen or so % in comparison to the tested installation.
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Illus. 5. The layout of the tested ventilation system based on the PN-EN 12237 standard stipulations
Components used to build Class C insulation system according to Eurovent are:
The LFX-REKU system is perfect for single family homes, offices, bars, restaurants or public utility buildings which asks for a high hygiene standard - for example, clinics.
All the current product information is available in the PRODUCTS tab - FLX REKU home ventilation