Osburn SATURNA, Installation And Operating Instructions Manual

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3.3.7.5 Altitude adjustment
All valves have been preset and certified for installation at elevations from 0 - 4500 feet (0-1372m)
above sea level. When installing this insert at higher elevations, it is necessary to decrease the input
rating, by changing the existing burner orifice to a smaller size, consult local codes. Input should be
reduced 4% for each additional 1000 feet above sea level. Use Tables 5A & 5B or check with the
local gas authorities for proper orifice size identification. For the USA, derate the heater from sea
level according to the gas installation code.
Altitude adjustment by changing the burner orifice
(Natural Gas)
ALTITUDE
up to (ft)
REDUCTION
(%)
ORIFICE SIZE
(DMS)
TARGET
INPUT
(BTU/hr)
MANIFOLD
PRESSURE
(in.wc)
4500 - 36 35,000 3.5
5500 4 37 33,600 3.5
6500 8 38 32,200 3.5
7500 12 39 30,800 3.5
8500 16 40 29,400 3.5
9500 20 40 28,000 3.5
10500 24 41 26,600 3.5
11500 28 42 25,200 3.5
TABLE 5A
(Propane / LP Gas)
ALTITUDE
up to (ft)
REDUCTION
(%)
ORIFICE SIZE
(DMS)
TARGET
UNPUT
(BTU/hr)
MANIFOLD
PRESSURE
(in. wc)
4500 - 50 35,000 10
5500 4 51 33,600 10
6500 8 51 32,200 10
7500 12 52 30,800 10
8500 16 52 29,400 10
9500 20 53 28,000 10
10500 24 53 26,600 10
11500 28 54 25,200 10
TABLE 5B