York DFAH User Manual
Page 32
107272-UIM-B-1105
32
Unitary Products Group
Table shows 4% Input Reduction per 1,000 ft. (304.8 m) Elevation. Reference Source: NFPA No. 54, ANSI Z 223.1, National Fuel Gas Code.
For Canadian high altitude {2000 - 4500 ft. (609.6 - 1,371.6)}, reduce gas manifold pressure to 3.0” w.c. (0.75 kPa) for Natural gas and for Propane gas.
SIZING FURNACE INPUT
The orifice spud supplied with all burners is the size for the minimum
BTU input of the burner for the type gas shown on the rating plate.
Table 18 shows the correct drill size for various inputs.
The correct manifold pressure for natural and LP gas is 3.5" w.c (0.87
kPa). Only minor adjustments in the input rate should be made by
adjusting the pressure regulator. The minimum manifold pressure
should be 3.0" w.c. (0.75 kPa) and the maximum pressure should be
3.5 w.c. (0.87 kPa) the next size larger or smaller orifice size should be
used if the desired input rating cannot be obtained within the above
manifold pressure adjustment range.
NOTE: The BTU input valves in the above table show the approximate
hourly input of the burner for the various drill sizes shown. To determine
the actual input of the burner, turn off all other gas appliances.
TABLE 18: High Altitude Duration Chart
NATURAL GAS
Elevation
Feet
56,000 — Input
70,000 — Input
77,000 — Input
90,000 — Input
Meters
Orifice
Dia.
Drill
Size
Part #
Orifice
Dia.
Drill
Size
Part #
Orifice
Dia.
Drill
Size
Part #
Orifice
Dia.
Drill
Size
Part #
Sea Level
0.136
29
9951--1361
0.154
23
9951--1541
0.161
20
9951--1611
0.180
15
9951--1801
2,000
618
0.136
29
9951--1361
0.149
25
9951--1491
0.157
22
9951--1571
0.177
16
9951--1771
3,000
914
0.128
30
9951--1281
0.149
25
9951--1491
0.157
22
9951--1571
0.173
17
9951--1731
4,000
1219
0.128
30
9951--1281
0.147
26
9951--1471
0.154
23
9951--1541
0.173
17
9951--1731
5,000
1524
0.128
30
9951--1281
0.144
27
9951--1441
0.152
24
9951--1521
0.169
18
9951--1691
6,000
1829
0.128
30
9951--1281
0.144
27
9951--1441
0.149
25
9951--1491
0.166
19
9951--1661
7,000
2134
0.120
31
9951--1201
0.140
28
9951--1401
0.147
26
9951--1471
0.161
20
9951--1611
8,000
2438
0.120
31
9951--1201
0.136
29
9951--1361
0.144
27
9951--1441
0.161
20
9951--1611
9,000
2743
0.120
31
9951--1201
0.136
29
9951--1361
0.140
28
9951--1401
0.157
22
9951--1571
10,000
3048
0.116
32
9951--1161
0.128
30
9951--1281
0.136
29
9951--1361
0.152
24
9951--1521
PROPANE GAS
Elevation
Feet
56,000 — Input
70,000 — Input
77,000 — Input
90,000 — Input
Meters
Orifice
Dia.
Drill
Size
Part #
Orifice
Dia.
Drill
Size
Part #
Orifice
Dia.
Drill
Size
Part #
Orifice
Dia.
Drill
Size
Part #
Sea Level
0.082
45
9951--0821
0.093
42
9951--0931
0.098
40
9951--0981
0.106
36
9951--1061
2,000
618
0.081
46
9951--0811
0.093
42
9951--0931
0.096
41
9951--0961
0.104
37
9951--1041
3,000
914
0.078
47
9951--0781
0.089
43
9951--0891
0.093
42
9951--0931
0.101
38
9951--1011
4,000
1219
0.078
47
9951--0781
0.089
43
9951--0891
0.093
42
9951--0931
0.101
38
9951--1011
5,000
1524
0.078
47
9951--0781
0.089
43
9951--0891
0.093
42
9951--0931
0.099
39
9951--0991
6,000
1829
0.076
48
9951--0761
0.086
44
9951--0861
0.089
43
9951--0891
0.098
40
9951--0981
7,000
2134
0.076
48
9951--0761
0.086
44
9951--0861
0.089
43
9951--0891
0.096
41
9951--0961
8,000
2438
0.073
49
9951--0731
0.082
45
9951--0821
0.086
44
9951--0861
0.096
41
9951--0961
9,000
2743
0.073
49
9951--0731
0.081
46
9951--0811
0.086
44
9951--0861
0.093
42
9951--0931
10,000
3048
0.070
50
9951--0731
0.078
47
9951--0781
0.082
45
9951--0821
0.089
43
9951--0891
TABLE 19: Gas Burner Settings
Gas
(@ 3.5” W.C.)
Firing Rate
BTU/Hr (kw)
Orifice
Size
Air Shutter
Setting
Natural
66,000 (19.3)
0.142” (3.61mm)
1.0
Natural
84,000 (24.6)
0.166” (4.22 mm)
3.5
LP
66,000 (19.3)
0.116” (2.95 mm)
2.0
LP
84,000 (24.6)
0.100” (2.54 mm)
3.5