3
INSTALLING THE CHANNELLING
The channels for exhaust air and incoming air should be installed, if possible, in a warm space below the vapour
barrier to suspended ceilings or casing. The vapour barrier remains intact and the channels do not need heat
insulation. This also ensures that the airflow in the channels will not freeze due to poor heat insulation as well as there
will be no condensing.
Cleansing of channels also becomes easier. The outside air and exhaust air channels are isolated under warm
conditions, see the instructions.
The channels are compiled of type-approved, rubber gasket parts and winded joint channel. Disconnections will be
removed for sealing and noise reasons. Connections will be secured with closing drawstrings and channels attached
securely to the framework with mounting strings so it will persist also cleaning.
Measuring- and regulation equipment of airflow are installed to exhaust channels after noise deductors and inflow
channels before the deductors. For cleansing, a cleansing hatch should be installed.
Remember, that a good functioning channel is: measured correctly, hermetic, carefully attached, properly isolated and
with hermetic inlets!
CHANNEL ISOLATION
Since the channels are mounted to the upper base, it must be
carefully isolated so that:
humidity will not condensate on pipe surfaces, the air will not freeze
before heat has been stored, the heated incoming air will not freeze
before it is blown into interior.
The two main rules of channel isolation are:
The warm air channels are always isolated in outer conditions with at
least 10 cm of mineral wool and windscreen plating. The cold air
channels are always isolated in inside premises with 10 cm of mineral
wool and steam barrier plating, for instance AE-chase or AIM-mat.
Insulation examples are shown in figure 4
CHANNELS OF OUTSIDE AND EXHAUST AIR
The outside air will be obtained through grate without an insect net.
The air inlet will be situated to as clean space as possible, far from the
refuse discharge, smokestack, ventilation outlet and exhaust air tube.
The air inlet will be located to a height of at least 2 meters from ground
on the northern side of the building, opposite side to the traffic. Due to
warm summer weather, the outlet channel has to be thermally isolated
in a loft space. Outgoing exhaust air will be channelled above the
rooftop through well-isolated channel and by 700-900mm high isolated
roof duct. (Figure 5).
Fireplaces like hearths, ovens and sauna heating systems must
have a separate isolated combustion air channels with slide coping.
Figure 4
Minimum insulation thickness of
the ventilation duct ( mm)
Rafter
Blown wool
Steam barrier
Mineral wool
Figure 5
Outdoor air inlet and
exhaust
air outlet.
size of the
duct / dm3/s
100
125
160
Temperature difference between the inside
and outside of the duct
5
o
C
30
30
30
20
40
80
10
o
C
30
40
40
20
o
C
50
50
50
30
o
C
60
60
60
40
o
C
80
80
80
50
o
C
100
100
100
Mineral wool
Supply air and
transfer air vents
Figure 6
INSTALLATION OF VENTS
Income and outlet vents are installed according to the plan.
Special attention is needed while installing income vents since a
wrong vent in a wrong place and wrong mounting will affect the air
draught and reduce satisfaction. Steam barriers are well tightened.
In saunas, the income air is channelled above the sauna stove and
outlet will be taken from underneath the sauna platform. The sauna
fans are manually adjustable.
In kitchens, the outlet appliance should be the stove hood with
adjustment plate of three positions and an airflow gauge. The exhaust
vent is operated by the means of the adjuster. The kitchen exhaust
will be attached to the air exchange unit.
In case sound isolation is needed between the separate rooms,
cushioned air transfer vents are used, figure 6. Air transfer routes in
doorways and under the doors will greatly reduce the privacy.
