Especially Airtight Properties:-
If the stove is being fitted in a property where the
design air permeability is less than 5m
3
/ (h.m
2
) (nor-
mally newer properties built from 2006), then a per-
manent ventilation must be fitted to provide 550mm
2
of ventilation for each kW of rated output.
10
Where such an installation exists, a test for spillage
should be made with the fan or fans and other appli-
ances using air in operation at full rate, (i.e.extrac-
tion fans, tumble dryers) with all external doors and
windows closed.
If spillage occurs following the above operation, an
additional air vent of sufficient size to prevent this
occurrence should be installed.
If a draught stabiliser is also fitted then the require-
ment is 850mm
2
per kW of rated output.
It is recommended to bring the air supply for the
stove into the house using a 4” plastic pipe. Where
the pipe meets the outside wall make sure a vent
cover is fitted properly to ensure no rodents can
enter via the vent pipe.
The vent pipe should be located to prevent the
ingress of moisture and in a location where it will not
get blocked with leaves or any other debris. As wind
effects can create suction and pressure zones of
opposite sides of the dwelling it is recommended to
run the air vent from opposite poles (North, South,
East & West) of the dwelling and tee off for the air
supply to the stove. This should negate the effect
of suction and pressure zones. See Fig. 7
‘HETAS product approval covers this appliance
when installed in accordance with the manufactur-
er’s instructions and relevant standards. As there is
currently no standard for Ducted Combustion Air
Supply this does not fall within the remit for HETAS
product approval. Responsibility for the specification
of this and for appropriate manufacturer’s instruc-
tions is carried by the appliance manufacturer, as
allowed for under the Building Regulations.’
Note: When Installing
outside air pipe must
adhere to ‘Clearance
t o C o m b u s t i b l e ’
Section.
Fig.7
HEAT RECOVERY VENTILATION
Where a stove is to be installed in a dwelling with
Heat Recovery Ventilation
(HRV) a number of
precautionary measures must be undertaken:
Should for example the delivery fan in the HRV unit
fail and the extraction fan in HRV fan continue to
run the HRV may create a pressure less than
atmospheric, this low pressure will effect the flue
pressure which is required to safely evacuate the
products of combustion from the stove.
1.
Fit an adequately sized vent in the room to pre-
vent pressure less than atmospheric occurring.
The size should be established by closing all
windows and doors and then creating the
possible failure situation. Then open a window
in the room where the stove is fitted, slowly
until the pressure reaches atmospheric. The
size of the window opening should be
measured and a vent of the corresponding size
installed.
2.
Fit a CO Alarm which has been approved to
EN 50291.
EXTERNAL DUCTED AIR
An outside air kit complete with primary air supply
can be ducted from outside and is available to order
for connection to the stove.
Note:
There must not be an extractor fan fitted in the
same room as the stove as this can cause the
stove to emit smoke and fumes into the room.
