ISH press release: LWE 40 decentral air ventilation unit with heat recovery

Fresh air without piping and energy waste

The LWE 40 decentral air ventilation unit is fitted in the outside wall. It ensures reliable good air quality and at the same time enables heat recovery from the extract air thanks to the integrated aluminium heat exchanger.

Decentral air ventilation units are an ideal retrofit solution for controlled ventilation in a room or several rooms. In some cases such systems, which are only installed in the exterior wall and need no further pipework, are also used in new buildings. These units can also be equipped with a heat recovery function – like the new LWE 40 from Stiebel Eltron. Thanks to regenerative heat transfer the aluminium heat exchanger charges with thermal energy from the extract air. After 40 seconds the EC fan changes direction and supplies fresh air from outside to the room. The thermal energy previously taken up is released to the ventilation air. This enables heating energy losses to be reduced by up to 90 per cent!

The units are used at least in pairs with two-way operation – so that no overpressure or negative pressure is created in the room. Depending on the requirements up to eight ventilation units can be operated with a control unit and a programming unit.

The integrated aluminium heat exchanger is a particular advantage of the LWE 40. It is extremely efficient and particularly easy to clean – rinsing under flowing hot water is usually sufficient, with a little detergent if needed. In addition, the unit is extremely quiet and has a very good filter effect as filters are fitted on both the inside and the outside. M5 or M7 particulate filters can even be used on the inside with only a slight reduction of the air volume flow.

The unit can be fitted in both square and round wall openings. Wall thicknesses of up to 800 millimetres can be bridged with a special telescopic casing. The air volume flow is between 20 and 70 cubic metres per hour with power consumption of between two and seven watts. The stabile fan speed enables reliable use in windy locations as well without any reduction of the air volume.