Exhaust air fans

Exhaust air fans are very suitable for functional rooms such as bathrooms, kitchens or utility rooms. They transport the exhaust air either directly outdoors or via exhaust air shafts. They are available from LUNOS with or without heat recovery. You can find out more under exhaust air system or in the exhaust air prospect.

The most important information about exhaust fans at a glance

Depending on the requirements, a distinction is made between centrifugal and axial fans. Centrifugal fans are generally used where larger volumes of air need to be extracted at a higher pressure (e.g. in multi-storey buildings with longer exhaust air ducts). Axial fans are generally used where moderate air volumes need to be extracted directly through the wall (e.g. in a WC in a detached house).

Centrifugal fans are slightly more expensive to purchase, but are also quieter and more energy efficient. Axial fans are ideal for smaller budgets and much easier to install, but cannot deliver large air volume flows in every installation situation.

Modern fans have flow-optimised impeller geometries and often have, for example, small holes in the impeller blades, serrations or unusual curves on certain components. These geometric optimisations prevent turbulence, thereby reducing noise and optimising the efficiency of the devices. A functioning exhaust air system often also includes a secondary air flow such as one or more fresh air vents.

Depending on the requirements, an exhaust air unit has different housing shapes, housing sizes, installation options or fan technologies, for example. Of course, a wide variety of control systems, e.g. with air sensors, motion detectors, wireless connections, smart home integration or switches and displays, can also be used together with exhaust air units.

Areas of application for exhaust air fans

Exhaust air fans are used in exhaust air rooms such as kitchens, bathrooms, toilets or utility rooms. In bedrooms, lounges or living rooms, other systems with different requirements in terms of function and running behaviour are installed - usually with heat recovery in modern buildings.

The importance of exhaust air fans

Exhaust air units are the basis of every modern ventilation system, which is used on a room-by-room basis as required. In the so-called hybrid ventilation concept, these devices are combined very sensibly with heat recovery devices and ventilate the existing exhaust air rooms.

A demand-controlled extract air fan in combination with permanently running heat recovery systems offers the best possible energy and cost efficiency and combines the advantages of all device concepts in one system. Pure exhaust air systems are being used less and less. The overall efficiency of the ventilation system plays a greater role in modern buildings. This can only be maximised with heat recovery.

However, comfort in buildings with pure extract air systems often no longer meets modern requirements. Cooler air can be fed into the rooms via outer wall air vents, which can lead to draughts under certain circumstances. This is by no means desirable in modern buildings. These systems are functional. This means that air exchange can be mechanised safely and cost-effectively. However, comfort, e.g. through the use of hybrid ventilation concepts, should not be neglected.