Zehnder Rittling ComfoAir 70 Installation Notes page 7

Installing the PVC mounting
block
The location of the ComfoAir 70 must
meet all local and national code
requirements. Ensure that proper clearance is
provided to other fixtures in bathrooms or other
"wet" rooms.
Install the mounting block into the wall opening
and ensure it is level. 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.
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 – shortening the PVC pipe
Before installing the ventilation unit, the
mounting 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. 3). Seal the gap
between the wall opening and the mounting
block with suitable sealant at both the interior
and exterior (Fig. 4).
After the installation, reapply the dust covers
to both sides of the PVC pipe.
Fig. 4 – sealant
Round mounting block
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