SERVICE AND TECHNICAL SUPPORT MANUAL
Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
440 04 4201 01
11
Table 3
Orifice Size and Manifold Pressure (in. w.c.) for Gas Input Rate
−
Modulating
S
A
G
L
A
R
U
T
A
N
F
O
Y
T
I
V
A
R
G
C
I
F
I
C
E
P
S
S
A
G
.
G
V
A
HEAT VALUE
0.58
0.60
0.62
0.64
AT ALTITUDE
Orifice Mnfld Press Orifice Mnfld Press Orifice Mnfld Press Orifice Mnfld Press
(Btu/cu ft)
No.
Max/Min
No.
Max/Min
No.
Max/Min
No.
Max/Min
900
43
3.8 /0.60
42
3.2 /0.50
42
3.3 /0.55
42
3.4 /0.55
0
925
43
3.6 /0.55
43
3.7 /0.60
43
3.8 /0.60
42
3.2 /0.50
(0)
950
43
3.4 /0.55
43
3.5 /0.55
43
3.6 /0.60
43
3.7 /0.60
975
44
3.7 /0.60
44
3.8 /0.60
43
3.4 /0.55
43
3.6 /0.55
to
1000
44
3.5 /0.55
44
3.6 /0.60
44
3.8 /0.60
43
3.4 /0.55
1025
44
3.3 /0.55
44
3.5 /0.55
44
3.6 /0.55
44
3.7 /0.60
2000
1050
44
3.2 /0.50
44
3.3 /0.55
44
3.4 /0.55
44
3.5 /0.55
(610)
1075
45
3.7 /0.60
45
3.8 /0.60
44
3.3 /0.50
44
3.4 /0.55
1100
46
3.7 /0.60
46
3.8 /0.60
45
3.8 /0.60
44
3.2 /0.50
U.S.A.
800
42
3.4 /0.55
42
3.5 /0.55
42
3.6 /0.55
42
3.7 /0.60
2001 (611)
825
43
3.8 /0.60
42
3.3 /0.50
42
3.4 /0.55
42
3.5 /0.55
to
850
43
3.6 /0.60
43
3.7 /0.60
42
3.2 /0.50
42
3.3 /0.55
3000 (914)
875
43
3.4 /0.55
43
3.5 /0.55
43
3.7 /0.60
43
3.8 /0.60
900
44
3.7 /0.60
44
3.8 /0.60
43
3.5 /0.55
43
3.6 /0.55
Canada
925
44
3.5 /0.55
44
3.6 /0.60
44
3.8 /0.60
43
3.4 /0.55
2001 (611)
950
44
3.3 /0.55
44
3.4 /0.55
44
3.6 /0.55
44
3.7 /0.60
to
975
44
3.2 /0.50
44
3.3 /0.50
44
3.4 /0.55
44
3.5 /0.55
4500 (1372)
1000
46
3.8 /0.60
45
3.8 /0.60
44
3.2 /0.50
44
3.3 /0.55
775
42
3.3 /0.55
42
3.4 /0.55
42
3.5 /0.55
42
3.6 /0.60
3001
800
43
3.8 /0.60
42
3.2 /0.50
42
3.3 /0.55
42
3.4 /0.55
(915)
825
43
3.6 /0.55
43
3.7 /0.60
43
3.8 /0.60
42
3.2 /0.50
850
44
3.8 /0.60
43
3.5 /0.55
43
3.6 /0.55
43
3.7 /0.60
875
44
3.6 /0.60
44
3.7 /0.60
43
3.4 /0.55
43
3.5 /0.55
4000
900
44
3.4 /0.55
44
3.5 /0.55
44
3.7 /0.60
44
3.8 /0.60
(1219)
925
44
3.2 /0.50
44
3.4 /0.55
44
3.5 /0.55
44
3.6 /0.55
950
45
3.7 /0.60
44
3.2 /0.50
44
3.3 /0.55
44
3.4 /0.55
750
42
3.3 /0.50
42
3.4 /0.55
42
3.5 /0.55
42
3.6 /0.55
4001
775
43
3.7 /0.60
43
3.8 /0.60
42
3.3 /0.50
42
3.4 /0.55
(1220)
800
43
3.5 /0.55
43
3.6 /0.60
43
3.7 /0.60
43
3.8 /0.60
825
44
3.8 /0.60
43
3.4 /0.55
43
3.5 /0.55
43
3.6 /0.60
850
44
3.5 /0.55
44
3.7 /0.60
44
3.8 /0.60
43
3.4 /0.55
5000
875
44
3.3 /0.55
44
3.5 /0.55
44
3.6 /0.55
44
3.7 /0.60
(1524)
900
44
3.2 /0.50
44
3.3 /0.50
44
3.4 /0.55
44
3.5 /0.55
925
46
3.8 /0.60
45
3.7 /0.60
44
3.2 /0.50
44
3.3 /0.55
725
42
3.2 /0.50
42
3.3 /0.55
42
3.4 /0.55
42
3.5 /0.55
5001
750
43
3.7 /0.60
43
3.8 /0.60
42
3.2 /0.50
42
3.3 /0.55
(1525)
775
43
3.4 /0.55
43
3.5 /0.55
43
3.7 /0.60
43
3.8 /0.60
800
44
3.7 /0.60
44
3.8 /0.60
43
3.4 /0.55
43
3.5 /0.55
825
44
3.5 /0.55
44
3.6 /0.55
44
3.7 /0.60
44
3.8 /0.60
6000
850
44
3.3 /0.50
44
3.4 /0.55
44
3.5 /0.55
44
3.6 /0.60
(1829)
875
45
3.7 /0.60
44
3.2 /0.50
44
3.3 /0.55
44
3.4 /0.55
900
46
3.7 /0.60
46
3.8 /0.60
45
3.8 /0.60
44
3.2 /0.50
675
42
3.4 /0.55
42
3.5 /0.55
42
3.6 /0.60
42
3.8 /0.60
6001
700
42
3.2 /0.50
42
3.3 /0.50
42
3.4 /0.55
42
3.5 /0.55
(1830)
725
43
3.6 /0.60
43
3.7 /0.60
43
3.8 /0.60
42
3.3 /0.50
750
43
3.4 /0.55
43
3.5 /0.55
43
3.6 /0.55
43
3.7 /0.60
775
44
3.6 /0.60
44
3.7 /0.60
43
3.4 /0.55
43
3.5 /0.55
7000
800
44
3.4 /0.55
44
3.5 /0.55
44
3.6 /0.60
44
3.7 /0.60
(2133)
825
44
3.2 /0.50
44
3.3 /0.55
44
3.4 /0.55
44
3.5 /0.55
850
46
3.8 /0.60
45
3.8 /0.60
44
3.2 /0.50
44
3.3 /0.55
(TABULATED DATA BASED ON 20,000 BTUH MAX-HEAT / 8,000 BTUH MIN-HEAT PER BURNER,
DERATED 2%/1000 FT (305M) ABOVE SEA LEVEL)
ALTITUDE
RANGE
ft (m)
U.
S
.A.
a
n
d
C
a
n
a
d
a
U
.S
.A
.
an
d
C
an
ad
a
U.
S
.A.
On
ly
to
U.
S
.A.
On
ly
to
U.
S
.A.
On
ly
to
U.
S
.A.
On
ly
to
MODULATING FURNACE
A11251A
