Lp Gas At High Altitudes - Rheem R95P Installation Instructions Manual

ORIFICE INSTALLATION
LP Gas is a manufactured gas that has consistent heating
value across most regions.
The NFGC guidelines are used with the following excep-
tion:
The recommended LP Gas high altitude orifice selections
differ slightly in that the NFGC LP orifice chart, as they are
not accurate for this furnace product. The National Fuel
Gas Code LP orifices are based on an 11 of water column
pressure at the orifice, which differs from this furnace prod-
uct 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 re-
duced by 4% per thousand ft. and the orifice size must be
selected based on the reduced input selection Table 14.
ORIFICE ORDERING INFORMATION
Orifice sizes are selected by adding the 2-digit drill size re-
quired in the orifice part number. Drill sizes available are
39 through 64; metric sizes available 1.10mm (-90):
Orifice Part Number 62-22175-(drill size)
Example 1:
# 60 drill size orifice required
Part # 62-22175-60
TABLE 14
LP GAS ORIFICE DRILL SIZE
(4% PER 1000 FT DE-RATE)
IMPORTANT: 90 Plus Models only.
Input (per
ltitude burner) 14000
0 to 2000 ft. 14,000
2000 -3000 12,320
3000 -4000 11,760
4000 -5000 11,200
5000 -6000 10,640
6000 -7000 10,080
7000 -8000 9,520
8000 -9000 8,960
9000 -10000 8400
TABLE 15
ALTERNATE METHOD FOR CANADIAN HIGH-ALTITUDE DERATE
IMPORTANT: 90 Plus Models only.
ALTITUDE
Orifice Size 0' - 2000'
1.10 mm
(factory kit)
#58
2001' - 4500'
#59
#59
#60
#60
#61
#62
#63
Example 2:
1.10 mm drill size orifice required
Part # 62-22175-90
ALTERNATE METHOD OF
CANADIAN HIGH-ALTITUDE
DERATE
In Canada, unless an orifice change is specifically man-
dated by local codes, an alternate method of altitude dera-
tion through a reduction in manifold pressure is acceptable
as described in Table 15.
The information in Table 15 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.
Once this field adjustment has been made, the label
shown in Figure 45 must be affixed in a conspicuous loca-
tion on the front of the furnace cabinet:
NOTE: This label is supplied in the information packet
shipped with each furnace.
NATURAL GAS
ORIFICE MANIFOLD
INPUT OUTPUT
SIZE PRESSURE
42,000 39,900
56,000 53,200
70,000 66,500
#51 3.5" W.C.
84,000 79,800
98,000 93,100
112,000 106,400
37,800 35,910
50,400 47,880
63,000 59,850
#51 3.0" W.C.
75,600 71,820
88,200 83,790
100,800 95,760
FIGURE 45
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
ALTITUDE INPUT OUTPUT
SIZE
42,000 39,900
56,000 53,200
70,000 66,500
0' - 2000' 1.15mm
84,000 79,800
98,000 93,100
112,000 106,400
37,800 35,910
50,400 47,880
63,000 59,850
2001' - 4500' 1.15mm
75,600 71,820
88,200 83,790
100,800 95,760
92-24399-01-01
MANIFOLD
PRESSURE
10" W.C.
7.6" W.C.
85