9
return air intakes should be located so that
they cannot become blocked. Similarly
these intakes must be positioned so as not
to draw in odours, fumes, hazardous
vapours or particles.
2.3 Air Supply for Combustion and
Ventilation
Consideration must be given to the provision
of air for the purposes of combustion and
ventilation of the heated space, plant room
or enclosure where the heaters are to be
installed .
It is strongly recommended that BS 6230 is
referred to for further information concerning
ventilation requirements.
2.3.1 Heaters installed within the
heated space
Where heaters are installed within the
heated space (i.e. not a plant room , or
enclosure) then:
Combustion air or heater related ventilation
air
will not be
required if -
•
The heaters are installed in room
sealed mode (ie with a positive
connection to atmosphere of both flue
and combustion air)
OR
•
If the design air change rate of the
heated space is 0.5 air changes per
hour or greater
The design air change rate may be satisfied
by natural infiltration or by mechanical
ventilation.
Combustion air ventilation
will be
required if
•
The heater(s) are installed with flue
only (ie without the positive connection
to atmosphere of a combustion air
duct)
And
•
The design air change rate of the
heated space is less than 0.5 air
changes per hour.
Where heater(s) are installed without the
positive connection of combustion ductwork
within a heated space where air change rate
of that heated space is less than 0.5 air
changes per hour then it will be necessary
to provide either natural ventilation openings
to the heated space (Section2.3.1.1 refers)
or the mechanical ventilation of the heated
space (Section2.3.1.2 refers).
2.3.1.1
Natural Ventilation Openings
to the Heated Space
If the heater(s) are to be installed without
the positive connection of combustion air
ductwork within a heated space, and where
the design air change rate of that heated
space is less than 0.5 air changes per hour,
then provision for low level natural
ventilation openings only will be necessary.
The minimum free area of the low level
natural ventilation opening shall be
•
2 cm
2
for each kW of rated heat input
The low level natural ventilation opening
should be situated on an external wall and
be within 1000 mm of floor level for natural
gas and ideally at floor level for lpg gas
installations but in any event no higher than
250 mm.
The table below provides specific data for
each heater model as -
2.3.1.2 Mechanical Ventilation to the
Heated Space
In the event that the heater(s) are to be
Minimum Free Area Of
Ventilation Opening
High Level
Low Level
cm
2
cm
2
30
None
64
50
None
107
72
None
158
95
None
211
120
None
263
145
None
315
MODEL
Содержание HT2000
Страница 51: ...51 Notes...