Installation Manual

48 Rinnai I-Series Condensing Boiler Solo Manual
The gas supply must be capable of handling the enre gas load
required at the locaon. Gas line sizing is based on gas type,
the pressure drop in the system, the gas pressure supplied,
and gas line type. For gas pipe sizing, refer to the Naonal Fuel
Gas Code, ANSI Z223.1/NFPA 54, or the Natural Gas and
Propane Installaon Code, CSA B149.1
For some tables, you will need to determine the cubic feet per
hour of gas required by dividing the gas input by the heang
value of the gas (available from the local gas company). The
gas input needs to include all gas products at the locaon and
the maximum Btu usage at full load when all gas products are
in use.
Use the table for your gas type and pipe type to nd the pipe
size required. The pipe size must be able to provide the
required cubic feet per hour of gas or the required Btu/hr.
The informaon below is provided as an example. The
appropriate table from the applicable code must be used.
Schedule 40 Metallic Pipe
Inlet Pressure: Less than 2 psi
Specic Gravity: 0.60
Informaon in table obtained from
NFPA 54, ANSI Z223.1.
Pressure Drop 0.5 in. w.c.
Nominal Pipe Size (in.)
1/2 3/4 1 1 1/4
Length in  (meters) Capacity in Cubic Feet of Gas per Hour
10 (3) 172 360 678 1,390
20 (6) 118 247 466 957
30 (9) 95 199 374 768
40 (12) 81 170 320 657
50 (15) 72 151 284 583
60 (18) 65 137 257 528
70 (21) 60 126 237 486
80 (24) 56 117 220 452
90 (27) 52 110 207 424
100 (30) 50 104 195 400
EXAMPLE
Rinnai Model Gas Input:
Addional Appliance Total Gas
Input:
Heang Value of Gas:
Cubic Feet Per Hour (CFH):
ANSWER:
B
65,000
Btu/hr
C
1,000
Btu/
3
A
150,000
Btu/hr
150,000+65,000
(CFH) =
1000
215
FT
3
/HR
CFH =
For this example, the pipe
diameter must be at least 3/4 in.
pipe size and 10  (3 m) in
length.
A + B
(CFH) =
C
Instrucons: Enter values in empty boxes.
Rinnai Model Gas Input:
Addional Appliance Total Gas Input:
Heang Value of Gas:
Cubic Feet Per Hour (CFH):
ANSWER:
B Btu/hr
C Btu/
3
A Btu/hr
(CFH) =
FT
3
/HR
CFH =
A + B
(CFH) =
C
GAS PIPE SIZING CALCULATION WORKSHEET
Natural Gas