Installation, Operation & Maintenance Manual
Bosch 96% AFUE Gas Furnace
| 37
Bosch Thermotechnology Corp.
|
04.2019
Data subject to change
9.3 Propane Gas (LP) Conversion
WARNING: FIRE OR EXPLOSION HAZARD
Possible property damage, personal injury or death may
occur if the correct conversion kits are not installed. The
appropriate kits must be applied to ensure safe and proper
furnace operation. All conversions must be performed by
a qualifi ed installer or service agency.
This unit is confi gured for natural gas. However, all furnaces come standard with a
conversion kit for propane gas (LP). The appropriate manufacturer's propane gas
conversion kit must be applied for propane gas (LP) installations. For high altitude
installations (above 2000 ft), refer to the "High Altitude Derate" section for details.
The indicated kits must be used to ensure safe and proper furnace operation. All
conversions must be performed by a qualifi ed installer, or service agency. Refer to
the installation instructions supplied with the conversion kit.
9.4 Gas Piping Connections
To avoid possible unsatisfactory operation or equipment damage due to underfi ring
of equipment, use the proper size of natural/propane gas piping needed when
running pipe from the meter/tank to the furnace.
When sizing a trunk line, be sure to include all appliances which will operate
simultaneously (see Table 16).
The gas piping supplying the furnace must be properly sized based on the gas fl ow
required specifi c gravity of the gas and length of the run. The gas line installation
must comply with local codes or in their absence refer to the latest version of
NFPA54/ANSI Z223.1.
Nominal iron
pipe size in.
Internal DIA.
in.
Length of pipe-ft
10
20
30
40
50
1/2
0.622 175
120
97
82
73
3/4
0.824
360
250
200
170
151
1
1.049
680
465
375
320
285
1-1/4
1.380
1400
950
770
660
580
1-1/2
1.610
2100
1460
1180
990
900
Table 16
Natural Gas Capacity of Pipe in Cubic Feet of Gas Per Hour (CFH)
(Pressure 0.5 psig or less and pressure drop of 0.3
in. WC
; Based on
0.60 Specifi c Gravity Gas)
CFH=
BTUH Furnace input
Heating Value of Gas (BTU/Cubic Foot)
To connect the furnace to the building's gas piping, the installer must supply a
ground joint union, drip leg, manual shutoff valve and line and fi ttings to connect
to gas valve. In some cases, the installer may also need to supply a transition piece
from 1/2" pipe to a larger pipe size.