Ducts, Grilles And Wall Cover; Roof Cap; Sealing The Gaps Around Ducts - Air Master AM 900 H Installation Manual

3.4.

Ducts, Grilles and Wall Cover

The length of the air ducts is calculated on the basis of the
thickness of the wall/dimensions of the roof.
NB! Please note that the duct holes in the wall must
have an outward downward gradient of 1-2% to
prevent heavy rain from entering the unit.
NB! Exhaust air ducts and supply air ducts must be
insulated against condensation on the ducts, if they
are within the building envelope.
NB! Condensation and heat insulation should be
performed according to standards and rules in effect.
NB! Fire requirements according to standards and
rules in effect must be observed.
NB! The installation of ventilation ducts should be
performed according to standards and rules in effect.
NB! Exhaust air ducts and supply air ducts must be
insulated against noise if they are visible. Service
access must be provided to all components.
Finally, fit a suitable circular grille with the slats pointing
downwards on the outside of the wall or a roof cap up on
the roof.
NB! The supply air grille is fitted with the slats pointing
downwards and the exhaust air grille is fitted with
vertical slats, at the AM 900 pointing to the right.
NB! To avoid an increase in noise level, it is important
that the pipes should not get twisted or compressed
against the air spigots of the unit.
NB! Remember to seal around the penetrations. See
section "Sealing the Gaps Around Ducts".
An external wall cover may be fitted as an optional alter-
native to grilles at the AM 900.
3.5.

Roof Cap

1
Fit roof caps on the roof to finish off the installation of
exhaust and supply through a roof. Installation will depend
on the roof construction (3). The illustration shows which
roof caps are for exhaust (1) and supply (2).
NB! Fire requirements for the installation of multiple
systems must be observed according to the standards
and rules in effect.
3.6.

Sealing the Gaps Around Ducts

Sealing of the gaps around ducts is performed as shown in
the sectional drawing below.
4
3
2
Application of a seal (shown here on a model with wall
ducts) is important at the ducts (3) indside and the outside
edges (4) in order to prevent draughts between the unit
(1) and the wall/roof (2) as well as between the ducts (3)
and the wall/roof (2).
Sealing on the inside between the pipes (3) and the wall/
ceiling (2) can also be performed between the air handling
unit (1) and the wall/roof (2) at position (5) before fitting
the air handling unit.
Depending on the condition of the wall/ceiling and the
dimensions of the air handling unit, a sealant that retains
elasticity over the long term or expanding sealing tape can
be used to obtain a flexible seal. This material is to be applied
to the rear of the unit around the air spigots, or at the side
of the duct holes on the wall to even out irregularities on
the wall/ceiling.
9
2
3
5
2
1
4
5