Fresh air diffuser with wind pressure safety device

The ZEWO SmartFan and ZEWO ObjektFan series of whisper-ledge ventilation units ensure a pleasant room climate. In addition, the matching fresh air diffuser with wind pressure protection (ALD for short) ensures that only little noise arrives in the living rooms from outside. At the same time, thanks to a special, integrated wind pressure safety device, interiors are protected from cooling and draughts even in strong winds. The outdoor air diffuser (ALD) achieves unique sound insulation values on the market; an air output of up to 31 m³/h is achieved at a 70 dB Normschallpegeldifferenz .

The ALD system can be easily combined with the ZEWO "SmartFan" and "ObjektFan" series of shell kits. The volume flow and sound insulation can be variably adjusted during installation thanks to the innovative sound insulation element. The sound insulation element consists of a ring with 3 chambers. Each chamber can be separately öffnen, so that flexibel can react to volume flow and sound requirements. In order to avoid cooling of the living spaces in case of high wind loads, the component for wind pressure protection has a non-return damper which closes automatically in case of high volume flows. A unique feature is the coarse dust filter unit, which sits in front of the system and has to be replaced independently.

Thus, the ALD system offers cost-effective controlled living space ventilation without heat recovery. Should the energy requirements increase later, the system can be easily retrofitted to controlled ventilation with heat recovery due to its modular design. The installation solutions for ventilation in intrados, attics or basements can also be equipped with the ALD.

Wind pressure protection and acoustic insulation elements

The ALD system consists of a wind pressure safety device with insect screen and specially developed sound insulation elements. The protection against wind is installed directly after the outer panel inside the ventilation unit. In the case of high volume flows, an integrated non-return damper closes immediately and automatically, thus preventing draughts and cooling of the living areas. The included insect filter and a further dust filter can be cleaned by hand from time to time. The ALD systems offer a wide range of variations. In the interior one can select between round or square and outside at the front between Kunststoff or metal screen. In addition to the standard version, the ALD system can easily be integrated into the reveal as well as into the roof and cellar.

Acoustic insulation elements

Special sound insulation elements have a special effect on the volume flow and the sound insulation. They consist of a sound-absorbing melamine resin foam that reduces fan and flow noise to a minimum. The elements are constructed in the form of a ring divided into three chambers. Since each chamber can be opened separately, it is possible to react flexibly to volume flow and sound requirements. This means that different room sizes with different air requirements can be optimally ventilated.


Finding the perfect place

ZEWOTHERM provides comprehensive advice on suitable ventilation concepts and gives tips on the correct positioning of an ALD system. For example, we recommend positioning the systems according to the cross ventilation principle. We recommend at least one external diffuser per closed room. Retrofitting ALD solutions to systems with heat recovery is also possible retrospectively without any problems. Therefore it does not matter whether it should be a free or fan-supported ventilation with bath ventilator: The ZEWO ALD solutions ensure a quiet, comfortable and constant air exchange in all interiors around the clock. Our technical staff will be happy to advise you.