Zehnder ComfoAir 70 Instructions De Montage page 7

Installing the mounting block
Install the mounting block into the wall opening
and ensure it is level.
Fig.3 - PVC pipe insert
Throughout the installation process,
ensure that the pipe remains level and
round - the inside diameter of the pipe must
not be out of round by more than +/- 1,5 mm
(1/16 inch) (Fig. 3).
Fig. 4 – shortening the PVC pipe
The mounting block has an external diameter of
250 mm (9 13/16 inch) and must be securely
fastened in the wall opening.
Only non-expanding adhesive or low expansion
foam may be used to secure the mounting block
in the opening.
Before installing the ventilation unit, the mount-
ing block must be cut to length so that it is flush
with the surface of the façade and the interior
surface of the wall (Fig. 4). To do this, the PVC
pipe must be shortened to the finished wall us-
ing a suitable tool.
Seal the gap between the wall opening and the
mounting block with suitable sealant at both the
interior and exterior (Fig. 5).
After the installation, reapply the dust covers
to both sides of the PVC pipe.
Fig. 5 – sealant
Round mounting block
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