Lmax calculator

The Lmax calculator is an easy to use tool which allows you to evaluate whether your ventilation extraction plan is viable.

You will need to input: the geographical location of the installation, the chosen appliance, the extraction exit and the number of bends.
As extraction exit the only remote fan unit that matters is the AR401. No other fan Untit has to be taken into account.
The calculator will work out the effect of these variables and provide you with the maximum remaining length of Gaggenau straight ducting that you can instal. If the answer is zero or below, the Lmax calculator will suggest how to improve the installation.

Each appliance has an Lmax rating: the maximum distance it can blow the air along a straight section of Gaggenau ducting. Air flow obstructions such as outlets and bends reduce that distance. For example, a bend may cause the same resistance as (be equivalent to) 3 metres of straight ducting. Keeping under the Lmax value ensures a good ventilation which will extract or filter the cooking vapours as quickly and as silent as possible.

Ducting should be as straight and as short a length from the appliance to the extraction exit as possible. The Lmax figures are based upon the using Gaggenau ducting. The good installation is one that achieves a figure below the Lmax rating.

In the AL200 example shown, the equivalent ducting length of the chosen accessories can be calculated as follows:

The Gaggenau wall outlet is equivalent to 11 meters of ducting and the two Gaggenau bends are equivalent to 6 meters of ducting. This is a total of 17 meters of equivalent ducting.

The appliance has an Lmax rating of 28 meters. Therefore the maximum remaining length of Gaggenau straight ducting that should be used is 11 metres.

For more information on the equivalent ducting length of Gaggenau ducting, bends and accessories, please refer to our PDF guide.