Bryant DURAPAC 579F User Manual
Page 9
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9
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VII. STEP 7 — ORIFICE CHANGE
This unit is factory assembled for heating operation using
natural gas at an elevation from sea level to 2000 ft. This
unit uses orifice type LH32RFnnn, where “nnn” indicates the
orifice size based on drill size diameter in thousands of an
inch.
A. High Elevation (Above 2000 ft)
Use accessory high altitude kit when installing this unit at
an elevation of 2000 to 7000 ft. For elevations above 7000 ft,
refer to Table 2 to identify the correct orifice size for the
elevation. See Table 3 for the number of orifices required for
each unit size. Purchase these orifices from your local Bryant
dealer. Follow instructions in accessory Installation Instruc-
tions to install the correct orifices.
Table 2 — Altitude Compensation*
*As the height above sea level increases, there is less oxygen per cubic
foot of air. Therefore, heat input rate should be reduced at higher alti-
tudes. Includes a 4% input reduction per each 1000 ft.
†Orifices available through your Bryant dealer.
Table 3 — Orifice Quantity
B. Conversion To LP (Liquid Propane) Gas
Use accessory LP gas conversion kit when converting this unit
for use with LP fuel usage for elevations up to 7000 ft. For
elevations above 7000 ft, refer to Table 4 to identify the correct
orifice size for the elevation. See Table 3 for the number of
orifices required for each unit size. Purchase these orifices
from your local Bryant dealer. Follow instructions in accessory
Installation Instructions to install the correct orifices.
Table 4 — LP Gas Conversion*
*As the height above sea level increases, there is less oxygen per
cubic foot of air. Therefore, heat input rate should be reduced at higher
altitudes. Includes a 4% input reduction per each 1000 ft.
†Orifices available through your Bryant dealer.
ELEVATION (ft)
NATURAL GAS ORIFICE†
Low Heat
High Heat
0-1,999
30
29
2,000
30
29
3,000
31
30
4,000
31
30
5,000
31
30
6,000
31
30
7,000
32
31
8,000
32
31
9,000
33
31
10,000
35
32
UNIT
ORIFICE QUANTITY
579F180 Low Heat
5
579F210 Low Heat,
579F240 Low Heat,
579F300 Low Heat,
579F180 High Heat
6
579F210 High Heat,
579F240 High Heat,
579F300 High Heat
7
ELEVATION (ft)
LP GAS ORIFICE†
0-1,999
36
2,000
37
3,000
38
4,000
38
5,000
39
6,000
40
7,000
41
8,000
41
9,000
42
10,000
43
INDUCED DRAFT
MOTOR
MAIN BURNER
SECTION
COMBUSTION
FAN HOUSING
HEAT EXCHANGER
SECTION
Fig. 10 — Combustion Fan Housing Location
3/4" FPT DRAIN
CONNECTION
1-3/8"
DRAIN HOLE
Fig. 11 — Condensate Drain Details (579F180 Shown)
Fig. 12 — Condensate Drain Piping Details