32
Table 12
M1/M5*B MoDEls & FoR usE WItH BloWER KIt no. 903773 1/4 HP 3 sPEED
FuRancE InPut
HEatInG sPEED
sEttInG
coolInG sPEED/ EVaP coIl
2 TON
2-1/2 ton
3 TON
086, 090
H
L
M
H
066, 070, 077
M
L
M
H
56
L
L
M
H
M1/M5*c MoDEls & FoR usE WItH BloWER KIt no. 903413 1/2 HP 4 sPEED
FuRancE InPut
HEatInG
sPEED
sEttInG
coolInG sPEED/ EVaP coIl
2 TON
2-1/2 ton & 3 ton
3-1/2 ton
4 TON
077, 086, 090
ML
L
ML
MH
H
056, 066, 070
L
L
ML
MH
H
M1/M5*D MoDEls & FoR usE WItH BloWER KIt no. 903890 3/4 HP 4 sPEED
FuRancE InPut
HEatInG
sPEED
sEttInG
coolInG sPEED/ EVaP coIl
2 TON
2-1/2 ton & 3 ton
3-1/2 ton & 4 ton
5 TON
077, 086, 090
ML
L
ML
MH
H
056, 066, 070
L
L
ML
MH
H
Table 12. a/c Blower speed selection chart
Table 11
Table 11. Equivalent orifice sizes for High altitude Installations
FuRnacE
MoDEls
oRIFIcE sIZE &
outPut caPacItY
altItuDE - FEEt
sEa
lEVEl
2,000
3,000
4,000
5,000
6,000
7,000
8,000
9,000 10,000
M1M - 056
Orifice Size - Nat. Gas
29
29
30
30
30
30
31
31
31
32
Orifice Size - LP
45
46
47
47
47
48
48
49
49
50
Output - MBTUH
45.4
41.8
40.1
38.5
37.0
35.5
34.1
32.7
31.4
30.2
M1M - 070
Orifice Size - Nat. Gas
24
25
26
27
27
28
28
29
29
30
Orifice Size - LP
42
42
43
43
43
44
44
45
46
47
Output - MBTUH
56.7
52.3
50.2
48.2
46.2
44.4
42.6
40.9
39.3
37.7
M1M - 077
Orifice Size - Nat. Gas
21
23
23
24
25
26
27
28
28
29
Orifice Size - LP
40
41
42
42
42
43
43
44
44
45
Output - MBTUH
61.7
56.9
54.6
52.4
50.3
48.3
46.4
44.5
42.7
41.0
M1M - 090
Orifice Size - Nat. Gas
17
18
19
19
20
21
22
23
24
26
Orifice Size - LP
36
37
38
38
39
40
41
41
42
43
Output - MBTUH
71.7
66.1
63.5
60.9
58.5
56.1
53.9
51.7
49.7
47.7
M1B - 066
Orifice Size - Nat. Gas
26
27
28
28
28
29
29
30
30
30
Orifice Size - LP
43
44
44
44
45
45
46
47
47
48
Output - MBTUH
52.6
48.5
46.6
44.7
42.9
41.2
39.6
38.0
36.5
35.0
M1B - 086
Orifice Size - Nat. Gas
18
19
19
20
21
22
23
24
26
27
Orifice Size - LP
37
38
39
39
40
41
42
42
43
43
Output - MBTUH
68.2
62.9
60.3
57.9
55.6
53.4
51.2
49.2
47.2
45.3
notEs: For Canadian high altitude (2,000 - 4,500’), reduce gas manifold pressure to 3.0” W.C. for natural gas and 9” W.C. for LP gas. (Includes
4% Input Reduction for Each 1,000 Feet). These specs do not apply to oil furnace installations. Reference Sources: ANSI Z233.1 & NFPA 54,
National Fuel Gas Code.
