11
2.3.2.2 Natural Ventilation Openings
to Plant Rooms for Flued Heaters
Where the heater(s) is installed in a plant
room and in flue mode (ie without a positive
connection to atmosphere of combustion air
ductwork ) the minimum free area of
ventilation opening needs to be
•
At high level 2 cm
2
for each kW of
rated heat input.
•
At low level 4 cm
2
for each kW of rated
heat input.
The high level ventilation opening should be
sited on an external wall and positioned as
high as is practical and always within the top
15% of the wall height
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 l.p.g gas
installations but in any event no higher than
250 mm.
The table below provides specific data for
each heater model as -
2.3.2.3 Natural Ventilation Openings
to Enclosures for Room Sealed
Heaters
For enclosure applications the minimum free
area of ventilation opening will also depend
upon whether the heater(s) is installed in
room sealed mode (ie with a positive
connection to atmosphere of both flue and
combustion air).
Or with flue only (ie without the positive
connection to atmosphere of a combustion
air duct)
Where the heater(s) is installed in a plant
room and in room sealed mode (ie with a
positive connection to atmosphere of both
flue and combustion air ) the minimum free
area of ventilation opening needs to be.
•
At high level 5 cm
2
for each kW of
rated heat input.
•
At low level 5 cm
2
for each kW of rated
heat input.
The high level ventilation opening should be
sited on an external wall and positioned as
high as is practical and always within the top
15% of the wall height.
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 l.p.g gas
installations but in any event no higher than
250 mm.
The table below provides specific data for
each heater model as -
2.3.2.4 Natural Ventilation Openings
to Enclosures for Flued Heaters
Where the heater(s) is in an enclosure and
in flue only mode (ie without a positive
connection to atmosphere of combustion air
ductwork ) the minimum free area of
ventilation opening needs to be:
Minimum Free Area Of
Ventilation Opening
High Level
Low Level
cm
2
cm
2
30
64
128
50
107
214
72
158
316
95
211
422
120
263
525
145
315
630
MODEL
Minimum Free Area Of
Ventilation Opening
High Level
Low Level
cm
2
cm
2
30
160
160
50
267
267
72
394
394
95
527
527
120
656
656
145
787
787
MODEL
Summary of Contents for HT2000
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