6
COMBUSTION AIR REQUIREMENTS –
Chart #2
(MINIMUM SQUARE INCHES OPENING)
MODEL
NUMBER
NUMBER
OF
MODULES
*UNCONFINED AREA
**CONFINED AREA
OUTSIDE COMBUSTION AIR
OUTSIDE
COMBUSTION
AIR 1 SQ. IN
/4000 Btu/hr
(SEE FIG. 2)
INSIDE
COMBUSTION
AIR 1 SQ. IN.
/1000 Btu/hr
(SEE FIG. 1)
VERT. DUCTS
1 SQ. IN.
/4000 Btu/hr
HORZ.
DUCTS
1 SQ. IN.
/2000 Btu/
hr
300
1
75
300
75
150
400
1
100
400
100
200
500
1
125
500
125
250
600
2
150
600
150
300
700
2
175
700
175
350
800
2
200
800
200
400
900
2
225
900
225
450
1000
2
250
1000
250
500
1100
3
275
1100
275
550
1200
3
300
1200
300
600
1300
3
325
1300
325
650
1400
3
350
1400
350
700
1500
3
375
1500
375
750
1600
4
400
1600
400
800
1700
4
425
1700
425
850
1800
4
450
1800
450
900
1900
4
475
1900
475
950
2000
4
500
2000
500
1000
2100
5
525
2100
525
1050
2200
5
550
2200
550
1100
2300
5
575
2300
575
1150
2400
5
600
2400
600
1200
2500
5
625
2500
625
1250
2600
6
650
2600
650
1300
2700
6
675
2700
675
1350
2800
6
700
2800
700
1400
2900
6
725
2900
725
1450
3000
6
750
3000
750
1500
* Unconfi ned area: A space whose volume is not less than 50 cubic feet per 1000 Btu
per hour of all appliances installed in that space (cubic feet of space = height x width
x length).
** Confi ned area: A space whose volume is less than 50 cubic feet per 1000 Btu per
hour of all appliances installed in that space (cubic feet of space = height x width x
length).
VENTILATION AND COMBUSTION AIR
WARNING
Air openings to combustion area must not be
obstructed. Follow Chart 2 to insure adequate
combustion air is maintained.
!
WARNING
Asphyxiation hazard. Ensure enough air is available
for proper combustion, avoiding hazard due to lack
of oxygen.
!