Lp Gas At High Altitude Elevations - Rheem RGFG Installation Instructions Manual

LP GAS AT HIGH ALTITUDE
ELEVATIONS IN THE U.S.
LP Gas is a manufactured gas that has
consistent heating value across most
regions.
The National Fuel Gas Code (N.F.G.C.)
guidelines are used with the following
exception:
The recommended LP Gas high altitude
orifice selections differ slightly in that
the NFGC LP orifice chart, as they are
not accurate for the RGFG gas fur-
naces. The National Fuel Gas Code LP
orifices are based on an 11" of water
column pressure at the orifice, which
differs from products that use 10" of
water column at the orifice. This differ-
ence requires a deviation from the
NFGC orifice size recommendations.
The Sea Level input should still be
reduced by 4% per thousand ft. and the
orifice size must be selected based on
the reduced input selection shown in
Table 13.
Orifice Ordering Information
Orifice sizes are selected by adding the
2-digit drill size required in the orifice
part number. Drill sizes available are 39
through 64; metric sizes available
1.10mm (-90) and 1.15mm (-91):
Orifice Part Number 62-22175-(drill
size)
Example 1:
#60 drill size orifice required
Part #62-22175-60
Example 2:
1.15mm drill size orifice required
Part #62-22175-91
TABLE 13
LP Gas Orifice Drill Size and per burner de-rate by elevation based
on 15,000 btu 90+ burners.
IMPORTANT: For 90+ Furnaces only. Do not use this chart for any
80+ Furnace.
Input (per
Altitude burner) 15000
0 to 2000 ft. 15000
2001 to 3000 13200
3001 to 4000 12600
4001 to 5000 12000
5001 to 6000 11400
6001 to 7000 1080
7001 to 8000 10200
8001 to 9000 9600
9001 to 10000 9000
ALTERNATE METHOD FOR
CANADIAN HIGH-ALTITUDE
DERATE
In Canada, unless an orifice change is
specifically mandated by local codes,
an alternate method of altitude deration
through a reduction in manifold pres-
sure is acceptable as described in
Table 14.
The information in Table 14 is based on
a heating value of 1000 BTU per cubic
feet of natural gas, and 2500 BTU per
cubic feet of LP gas.
IMPORTANT: Actual input rates must
be measured on-site with manifold
pressure adjustment to ensure that an
actual 10% reduction in input rate is
achieved.
TABLE 14
ALTERNATE METHOD FOR CANADIAN HIGH-ALTITUDE DERATE
IMPORTANT: 90+ MODELS ONLY. DO NOT USE THIS CHART FOR ANY 80 PLUS MODELS.
NATURAL GAS
ALTITUDE INPUT OUTPUT
45,000 40,500
60,000 54,000
75,000 67,500
0' - 2000'
90,000 81,000
105,000 94,500
120,000 108,000
40,500 36,450
54,000 48,600
67,500 60,750
2001' - 4500'
81,000 72,900
94,500 85,050
108,000 97,200
Orifice
Size
1.15 mm (factory)
1.15 mm
1.10 mm
#58
#59
#60
#62
#63
#64
Once this field adjustment has been
made, the label shown in Figure 35
must be affixed in a conspicuous
location on the front of the furnace
cabinet:
NOTE: This label is supplied in the
information packet shipped with each
furnace.
ORIFICE MANIFOLD
ALTITUDE
SIZE PRESSURE
#50 3.5" W.C. 0' - 2000'
#51 3.0" W.C. 2001' - 4500'
FIGURE 35
MANIFOLD PRESSURE-CHANGE LABEL
THE MANIFOLD PRESSURE OF THIS APPLIANCE HAS
BEEN FIELD ADJUSTED TO OBTAIN THE CORRECT
INPUT RATING FOR INSTALLATION AT ALTITUDES
BETWEEN 2,000 FEET AND 4,500 FEET ELEVATION.
LA PRESSION DU DISTRIBUTEUR D'ALIMENTATION
DE CET APPAREIL A ÉTÉ AJUSTÉ SUR LES LIEUX AFIN
D'OBTENIR LA BONNE PUISSANCE D'ENTRÉE POUR
UNE INSTALLATION ENTRE 2000 ET 4500 PIEDS
D'ALTITUDE.
LP GAS
ORIFICE MANIFOLD
INPUT OUTPUT
SIZE PRESSURE
45,000 40,500
60,000 54,000
75,000 67,500
1.15mm 10" W.C.
90,000 81,000
105,000 94,500
120,000 108,000
40,500 36,450
54,000 48,600
67,500 60,750
1.10mm 7.6" W.C.
81,000 72,900
94,500 85,050
108,000 97,200
92-24399-01-01
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