Equivalent Orifice Sizes At High Altitudes - Nordyne M1B Series Owner's Manual & Installation Instructions

21. EQUIVALENT ORIFICE SIZES AT HIGH ALTITUDES

(Includes 4% Input Reduction for Each 1,000 Feet)
FURNACE ORIFICE SIZE AND
MODEL OUTPUT CAPACITY
ORIFICE SIZE - NAT. GAS
M1M/G 056 ORIFICE SIZE - LP
OUTPUT- MBTUH
ORIFICE SIZE - NAT. GAS
M1M/G 070 ORIFICE SIZE - LP
OUTPUT- MBTUH
ORIFICE SIZE - NAT. GAS
M1M 077 ORIFICE SIZE - LP
OUTPUT- MBTUH
ORIFICE SIZE - NAT. GAS
M1G 077 ORIFICE SIZE - LP
OUTPUT- MBTUH
ORIFICE SIZE - NAT. GAS
M1M 090 ORIFICE SIZE - LP
OUTPUT- MBTUH
ORIFICE SIZE - NAT. GAS
M1G 090 ORIFICE SIZE - LP
OUTPUT- MBTUH
ORIFICE SIZE - NAT. GAS
M1B 066 ORIFICE SIZE - LP
OUTPUT- MBTUH
ORIFICE SIZE - NAT. GAS
M1B 086 ORIFICE SIZE - LP
OUTPUT- MBTUH
Reference Sources: ANSI Z233.1 & NFPA 54, National Fuel Gas Code.
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.
NOTE: Do not attempt to change the size of an orifi ce by drilling it out. To do so will
void the manufacturer's warranty
O'Fallon, MO
SEA LEVEL 2000
29
45
45.4
24
42
56.7
21
40
61.7
21
40
59.9
17
36
71.7
17
36
69.7
26
43
52.6
18
37
68.2
Table 12. High Altitude
INSTALLER: Please leave
these installation instructions
with the homeowner.
¢708672;¤
708672A
ALTITUDE - FEET
3000 4000 5000 6000
29 30 30 30
46 47 47 47
41.8 40.1 38.5 37.0
25 26 27 27
42 43 43 43
52.3 50.2 48.2 46.2
23 23 24 25
41 42 42 42
56.9 54.6 52.4 50.3
23 23 24 25
41 42 42 42
55.2 53.0 50.9 48.9
18 19 19 20
37 38 38 39
66.1 63.5 60.9 58.5
18 19 19 20
37 38 38 39
64.2 61.7 59.2 56.8
27 28 28 28
44 44 44 45
48.5 46.6 44.7 42.9
19 19 20 21
38 39 39 40
62.9 60.3 57.9 55.6
Specifi cations and illustrations subject to change
without notice and without incurring obligations.
7000 8000 9000 10000
30 31 31 31
48 48 49 49
35.5 34.1 32.7 31.4
28 28 29 29
44 44 45 46
44.4 42.6 40.9 39.3
26 27 28 28
43 43 44 44
48.3 46.4 44.5 42.7
26 27 28 28
43 43 44 44
46.9 45.0 43.2 41.5
21 22 23 24
40 41 41 42
56.1 53.9 51.7 49.7
21 22 23 24
40 41 41 42
54.6 52.4 50.3 48.3
29 29 30 30
45 46 47 47
41.2 39.6 38.0 36.5
22 23 24 26
41 42 42 43
53.4 51.2 49.2 47.2
708672A (Replaces 7086720)
Printed in U.S.A. (09/09)
32
50
30.2
30
47
37.7
29
45
41.0
29
45
39.8
26
43
47.7
26
43
46.3
30
48
35.0
27
43
45.3