Atag WO61 BM Serie Mode D'emploi Et Instructions D'installation page 76

installation
general
clearance required
fitting possibilities
GB 14
The minimum distance between the supporting surface for
the cooking vessels on the hob and the lowest part of the
range hood must be not less than 650 mm from electric
cookers and 700 mm from gas or mixed cookers.
If the instructions for installation for the gas hob specify a
greater distance, this must be adhered to.
You can use the extractor hood for recirculation or for
extraction. An extractor hood blows the fumes through the
discharge to the outside.
In the case of a recirculation hood, a carbon filter removes
the fumes. The clean air is blown back into the kitchen.
For instructions on installing the carbon filter see "setting" on
page 10.
650/700