Bryant COMMERCIAL SINGLE PACKAGE ROOFTOP GAS HEAT/ELECTRIC COOLING 581B - Manual (Page 44)

44
PERFORMANCE DATA (cont)
ALTITUDE COMPENSATION*
581B036-072
* 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.
†Orifices available through your Bryant distributor.
ALTITUDE COMPENSATION*
581B090-150
*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.
†Orifices available through your local Bryant distributor.
ALTITUDE DERATING FACTOR*
581B036-150
*Derating of the unit is not required unless the heating value of the
gas exceeds the values listed in the table above, or if the elevation
exceeds 6000 ft. Derating conditions must be 4% per thousand ft
above sea level. For example, at 4000 ft, if the heating value of the
gas exceeds 1000 Btu/ft
3 , the unit will require a 16% derating. For
elevations above 6000 ft, the same formula applies. For example, at
7000 ft, the unit will require a 28% derating of the maximum heating
value per the National Fuel Gas Code.
ELEVATIO
N
(ft)
72,000 AND 115,000/
60,000 and 90,000
BTUH NOMINAL
INPUT*
150,000/120,000 BTUH
NOMINAL INPUT
Natural
Gas
Orifice
Size†
Liquid
Propane
Orifice
Size†
Natural
Gas
Orifice
Size†
Liquid
Propane
Orifice
Size†
0-2,000 33/38 43/45 30/32 38/42
2,000 34/39 43/46 30/33 39/42
3,000 35/40 44/47 31/34 40/43
4,000 36/41 44/47 32/35 41/43
5,000 36/41 44/48 33/35 42/43
6,000 37/42 45/48 34/36 43/44
7,000 37/42 45/49 35/37 43/44
8,000 38/43 46/49 36/37 44/45
9,000 39/43 47/50 37/38 44/46
10,000 41/44 48/50 38/40 45/47
11,000 43/45 48/51 39/41 45/48
12,000 44/45 49/51 40/42 46/49
13,000 44/46 49/52 41/43 47/49
14,000 45/47 50/52 42/43 47/50
ELEVATION
(ft)
125,000-224,000 BTUH
NOMINAL INPUT
250,000 BTUH
NOMINAL INPUT
Natural
Gas
Orifice
Size†
Liquid
Propane
Orifice
Size†
Natural
Gas
Orifice
Size†
Liquid
Propane
Orifice
Size†
0-2,000 31 41 30 38
2,000 32 42 30 39
3,000 32 42 31 40
4,000 32 42 32 41
5,000 33 43 33 42
6,000 34 43 34 43
7,000 35 44 35 43
8,000 36 44 36 44
9,000 37 45 37 44
10,000 38 46 38 45
11,000 39 47 39 45
12,000 40 47 40 46
13,000 41 48 41 47
14,000 42 48 42 47
ELEVATION
MAXIMUM HEATING VALUE
(Btu/ft 3 )
0-2000 1100
2001-3000 1050
3001-4000 1000
4001-5000 950
5001-6000 900