Table of Contents
Advertisement
WARNING
!
Asphyxiation, fi re hazard. Do not obstruct air
openings to combustion area. Follow instructions
below, to maintain adequate combustion air.
Input (Mbh)
Combustion Air
1 Sq.In./5000 BTU/Hr
126
175
259
294
* 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)
Ventilation of boiler room must be adequate enough to
1.
provide suffi cient air to properly support combustion,
venting and maintain safe ambient temperatures under
normal operating conditions.
When the boiler is located in an unconfi ned space in a
2.
building of conventional construction frame, masonry
or metal, infi ltration normally is adequate to provide
air for combustion and ventilation. However, in any
building which has been altered to conserve energy
or to minimize infi ltration, the boiler area should
be considered as a confi ned space. If there is any
doubt, install air supply provisions for combustion
and ventilation in accordance with Chapter 5, Air for
Combustion and Ventilation, of NFPA 31, Standard
for the Installation of Oil Burning Equipment. The
recommendations that follow, or applicable provisions
of the local building codes.
When the boiler is installed in an unconfi ned space,
3.
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
appliances 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.
VENTILATION AND COMBUSTION AIR
COMBUSTION AIR REQUIREMENTS
(Minimum Opening Requirement)
Unconfi ned Area*
Outside
Combustion Air
1 Sq. In./1000 BTU/
Hr (Min. 100 Sq. In.)
(Step 4)
26
35
52
59
Inside
1 Sq. In./4000 BTU/Hr
(Figures # 2 & #3)
(Figure #1)
126
175
259
294
When air for combustion and room ventilation is from
4.
inside buildings, the confi ned space shall be provided
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
interior areas having adequate infi ltration from the
outside. See Figure #3.
Figure #3
L TYPE VENT PIPE
BASEBOARD
VENT PIPE
6
Confi ned Area**
Outside Combustion Air
Vertical Ducts
1 Sq. In./2000 BTU/Hr
32
44
65
74
CHIMNEY
OR
12"
12"
Horizontal Ducts
(Figure # 4)
63
88
130
147
VENTS
Advertisement
Table of Contents
