Gas Piping

Pipe Sizing Procedure - Example

The gas supply must be capable of handling the entire gas load at the location. 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 in the United States, refer to the National Fuel Gas Code, NFPA 54. For Canadian gas pipe sizing, refer to the Natural Gas and Propane Installation Code CAN/CSA B149.1. The below information is provided as an example. The appropriate table from the applicable code must be used.

1.For some tables, you will need to determine the cubic feet per hour of gas required by dividing the gas input by the heating value of the gas (available from the local gas company). The gas input needs to include all gas products at the location and the maximum BTU usage at full load when all gas products are in use.

Gas Input of all gas products (BTU / HR)

Cubic Feet per Hour (CFH) =

Heating Value of Gas (BTU / FT 3 )

2.Use the table for your gas type and pipe type to find the pipe size required. The pipe size must be able to provide the required cubic feet per hour of gas or the required BTU/hour.

Example: The heating value of natural gas for your location is 1000 BTU/FT3. The gas input of the RC98i is 199,000 BTU/HR. Additional appliances at the location require 65,000 BTU/hr. Therefore the cubic feet per hour = (199,000 + 65,000) / 1000 = 264 FT3/HR. If the pipe length is 10 feet then the 3/4 inch pipe size is capable of supplying 264 FT3/HR of natural gas.

Length

 

Pipe Size (inches)

 

3/4

1

1 1/4

1 1/2

 

10

273

514

1060

1580

20

188

353

726

1090

30

151

284

583

873

40

129

243

499

747

50

114

215

442

662

60

104

195

400

600

70

95

179

368

552

80

89

167

343

514

 

 

 

 

 

90

83

157

322

482

 

 

 

 

 

100

79

148

304

455

 

 

 

 

 

125

70

131

269

403

 

 

 

 

 

150

63

119

244

366

 

 

 

 

 

175

58

109

224

336

 

 

 

 

 

200

54

102

209

313

 

 

 

 

 

Length

 

Pipe Size (inches)

 

 

 

 

 

1/2

3/4

1

1 1/4

 

 

 

 

 

 

10

291

608

1150

2350

 

 

 

 

 

20

200

418

787

1620

 

 

 

 

 

30

160

336

632

1300

 

 

 

 

 

40

137

287

541

1110

 

 

 

 

 

50

122

255

480

985

 

 

 

 

 

60

110

231

434

892

 

 

 

 

 

80

101

212

400

821

 

 

 

 

 

100

94

197

372

763

 

 

 

 

 

125

89

185

349

716

 

 

 

 

 

150

84

175

330

677

 

 

 

 

 

175

74

155

292

600

 

 

 

 

 

200

67

140

265

543

 

 

 

 

 

Manual - Rinnai Condensing Water Heaters

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Rinnai RC80E, RC98I, RC98E, RC80I installation manual Pipe Sizing Procedure Example

RC80E, RC80I, RC98E, RC98I specifications

The Rinnai RC80E, RC98I, RC98E, and RC80I are high-efficiency tankless water heaters that exemplify leading-edge technology and engineering. Designed to meet the demands of modern households, these units provide continuous hot water while offering energy savings and compact sizes.

Starting with the RC80E, this model features a maximum flow rate of 8 gallons per minute, making it suitable for smaller homes or multi-family settings. It incorporates Rinnai's Circ-Logic technology, allowing homeowners to customize their hot water recirculation. This means users can schedule hot water availability, ensuring comfort while minimizing water waste.

The RC98I and RC98E models elevate performance, boasting a maximum flow rate of 9.8 gallons per minute. The "I" in RC98I stands for internal, indicating its built-in temperature control and Wi-Fi connectivity options. This allows for remote monitoring and control via a smartphone app, enhancing user convenience. In contrast, the "E" in RC98E indicates it has an external setting, providing flexibility for homeowners seeking installation options that cater to their specific needs.

All four models feature Rinnai’s condensing technology, which utilizes a dual heat exchanger design for superior efficiency. This not only lowers energy costs but also reduces CO2 emissions, aligning with eco-friendly standards. Additionally, they operate at an impressive Uniform Energy Factor (UEF), which is crucial for energy-conscious homeowners.

Safety is a significant consideration in Rinnai’s design philosophy. The RC80E, RC98I, RC98E, and RC80I come equipped with multiple safety features, including overheating protection and venting safeguards, ensuring peace of mind during operation. Their compact size allows for versatility in installation, fitting into tight spaces and freeing up valuable room in your home.

Moreover, these water heaters are designed for longevity, featuring a durable construction that resists corrosion. Rinnai's commitment to quality is evident in their extensive warranty, proving their confidence in the product’s reliability.

In summary, the Rinnai RC80E, RC98I, RC98E, and RC80I units represent a blend of advanced technology, efficiency, and convenience. With significant flow rates, innovative features like Circ-Logic and Wi-Fi compatibility, as well as robust safety measures, they are an excellent choice for any homeowner looking to enhance their hot water experience while promoting energy efficiency.