41
ALTITUDE ABOVE
SEA LEVEL
LOCAL HEATING VALUE, BTU PER CUBIC FOOT
650
700
750
800
850
900
950
1,000
1,050
2,000 FT
LOW
LOW
LOW
LOW
LOW
LOW
HIGH
HIGH
HIGH
3,000 FT
LOW
LOW
LOW
LOW
LOW
LOW
HIGH
HIGH
HIGH
4,000 FT
LOW
LOW
LOW
LOW
LOW
HIGH
HIGH
HIGH
HIGH
5,000 FT
LOW
LOW
LOW
LOW
LOW
HIGH
HIGH
HIGH
HIGH
6,000 FT
LOW
LOW
LOW
LOW
HIGH
HIGH
HIGH
HIGH
HIGH
7,000 FT
LOW
LOW
LOW
LOW
HIGH
HIGH
HIGH
HIGH
HIGH
8,000 FT
LOW
LOW
LOW
HIGH
HIGH
HIGH
HIGH
HIGH
HIGH
9,000 FT
LOW
LOW
LOW
HIGH
HIGH
HIGH
HIGH
HIGH
HIGH
10,000 FT
LOW
LOW
HIGH
HIGH
HIGH
HIGH
HIGH
HIGH
HIGH
Table 12. Natural Gas Heating Values
Table 11. High Altitude Deration Chart for Propane Gas
PROPANE GAS
ALTITUDE ABOVE
SEA LEVEL
INPUT (BTU)
54,000
72,000
90,000
108,000
0 to 1,999 FT
56
56
56
56
ORIFICE SIZE
10.0
10.0
10.0
10.0
MANIFOLD PRESSURE
2,000 to 2,999 FT
56
56
56
56
ORIFICE SIZE
9.0
9.0
9.0
9.0
MANIFOLD PRESSURE
3,000 to 4,999 FT
56
56
56
56
ORIFICE SIZE
8.5
8.5
8.5
8.5
MANIFOLD PRESSURE
5,000 to 5,999 FT
57
57
57
57
ORIFICE SIZE
10.0
10.0
10.0
10.0
MANIFOLD PRESSURE
6,000 to 7,999 FT
57
57
57
57
ORIFICE SIZE
9.0
9.0
9.0
9.0
MANIFOLD PRESSURE
8,000 to 10,000 FT
57
57
57
57
ORIFICE SIZE
8.5
8.5
8.5
8.5
MANIFOLD PRESSURE