1104UESAGBEN, page 14/31
Figure 9
Approved appliances type
B.
For illustrative purposes
only. For actual pipe con-
nections see
fi
gure 8.
B22 - roof
B22 - wall
It is important to ensure that there is an adequate air supply at all times for both
combustion and heating requirements. Modern buildings involve greater use of in-
sulation, improved vapour barriers, and weather proo
fi
ng. These practices mean
that buildings are sealed much tighter than in the past.
Proper combustion air supply for a power vented Type B installation requires ven-
tilation of the heated space. Natural in
fi
ltration of air may not be adequate. Use
of exhaust fans aggravates this situation. It is important to ensure that there is
adequate combustion air supply at all times. Reliance on doors and windows is
not permitted.
Always ensure that adequate combustion air is provided to suit the total instal-
lation of all combustion equipment in accordance with BS6230 or BS5440 as
appropriate.
Ensure that the air combustion inlet opening at the rear side of the unit cannot be
obstructed (see.
fi
g. 8).
Air supply
WARNING
When these air heaters
are installed as type B
appliances, they take
their air for combustion
from the space in which
they are installed. Do not
restrict the combustion air
intake.
6.2.3 Combustion air inlet pipe &
fl
ue pipe for balanced
fl
ue instal-
lation (type C appliances)
Balanced
fl
ue air heaters are designed to be
fi
tted with a combustion air inlet pipe
that draws in outdoor air and a
fl
ue pipe that exhausts
fl
ue products to outdoors.
Both the
fl
ue and combustion air pipes must be sealed. Use gasket sealed seam-
less aluminium pipe or equivalent.
C2 appliances must not be applied !