Ventilation And Combustion Air - UTICA BOILERS SFE0365 Installation, Operation And Maintenance Manual

Air openings to combustion area must not be obstructed. By following the instructions below,
adequate combustion air can be maintained.
Combustion Air 1 Sq.
BTU/Hr Input
In./5000 BTU/Hr
91,000
140,000
175,000
210,000
245,000
280,000
* A space whose volume is not less than 50 cubic feet per 1000 BTU/Hour of all appliances installed in that space (cubic feet of space = height x width x length)
** A space whose volume is less than 50 cubic feet per 1000 BTU/Hour of all appliances installed in that space (cubic feet of space = height x width x length)
1. Ventilation of boiler room must be adequate enough
to provide sufficient air to properly support combustion
and venting.
2. When the boiler is located in an unconfined space in a
building of conventional construction frame, masonry
or metal, infiltration normally is adequate to provide air
for combustion and ventilation. However, in any build-
ing which has been altered to conserve energy or to
minimize infiltration, the boiler area should be consid-
ered as a confined space. If there is any doubt, install
air supply provisions for combustion and ventilation in
accordance with section 5.3, Air for Combustion and
Ventilation, of the NFPA 54 1988 code, the recommen-
dations that follow, or applicable provisions of the local
building codes.
3. When the boiler is installed in an unconfined space,
in a building of unusually tight construction, air for
combustion and room ventilation must be obtained
from outdoors or from spaces freely communicating
with the outdoors. A permanent opening or openings
having a total free area of not less than 1 square inch
per 5,000 BTU per hour of total input rating of all appli-
ances shall be provided. Ducts may be used to convey
make-up air from the outdoors and shall have the same
cross-sectional area of the openings to which they are
connected.
4. When air for combustion and room ventilation is from
inside buildings, the confined space shall be provided

VENTILATION AND COMBUSTION AIR

cOMBUStiON aiR REQUiREMENtS
(Minimum Opening Requirement)
Unconfined Area*
Outside
Combustion Air 1 Sq.
(Step 4) (Min. 100 Sq. In.) (Figure #1)
19
28
35
42
49
56
WARNING
!
Inside
Vertical Ducts 1 Sq. In./4000 BTU/
In./1000 BTU/Hr
100
140
175
210
245
280
with two permanent openings, one starting 12 inches
from the top and one 12 inches from the bottom of the
enclosed space. Each opening shall have a minimum
free area of 1 square inch per 1,000 BTU per hour of
the total input rating of all appliances in the enclosed
space, but must not be less than 100 square inches.
These openings must freely communicate with the inte-
rior areas having adequate infiltration from the outside.
(Figure #3)
5. When the boiler is installed in a confined space and all
air is provided from the outdoors, the confined space
5
Confined Area**
Outside Combustion Air
Hr (Figures # 2 & #3)
23
35
44
53
61
61
Figure #3
CHIMNEY
OR
L TYPE VENT PIPE
BASEBOARD
12"
VENT PIPE
12"
Horizontal Ducts 1 Sq. In./2000
BTU/Hr (Figure # 4)
46
70
88
106
122
140
VENTS