Fall 2012 Things To Know About Tankless Water …

1 Fall 2012. Things To know About Tankless Water Heaters II. In the last Think Safety, we are the most common culprits looked at some basic elements of early service calls. of a Tankless Water heater such Venting is another impor- as how they work, when to tant component in the tank- use them and sizing the Water less Water heater installation. heater for the application. An improper vent installation In this issue, we will focus can lead to several problems on some essentials of installa- that can shorten the life of the tion.

2 The Water heater will not Water heater, produce trouble- work to its maximum efficien- some operation, or in extreme cy and output if the Water and cases keep the Water heater gas lines are sized incorrectly. from functioning at all. Undersized gas and Water lines Sizing Supply Lines: In order for the Tankless wa- The gas line leading to the ter heater to operate correctly Water heater must be sized and supply the most hot Water correctly. Let's assume we are possible, both the Water and going to install a Tankless Water gas supply lines must be sized heater with a maximum BTU.

3 Correctly. rating of 199,000. The home Water and gas lines coming also will have an 80,000 BTU. into the Water heater should furnace, a 65,000 BTU gas be around inch. If the wa- range and a 32,000 BTU set Inside .. ter line is too small, the Water of gas logs. The tank will be heater will be unable to pro- 50 feet from the house. Use duce its maximum flow rate Table 1, 2 or 3 on page two to Sizing Page 2. downstream. If the gas line determine the size yard line is too small, the Water heater needed to supply adequate gas Two-pound Page 3 will act like any other appliance pressure.

4 Table 1 is for copper starved for fuel. It may even tubing and Table 2 or 3 for shut down. Continued to Next Page Two-pound Line Page 3. Articles in this publication are for information only. Nothing in this publication is to be construed as setting standards or Venting Page 3. requirements. Please consult with appropriate regulatory and rulemaking bodies for all legal requirements. Think Safety! Fall 2012 Page 2. Sizing Supply Lines: Continued from Page One tubing or poly pipe is used, 60 feet. The total load will be carried by the branch.

5 These inch tubing would be required. 376,000 BTU/hour. Use Table pipe sizes are minimums. For poly tubing. For second stage piping, 4. The first section of pipe or simplicity, of course all lines The total BTU/hour load measure the distance from main trunk line, will carry the could be piped with the larger would be 376,000 BTU/hour. the second stage regulator to whole load. This section of pipe sizes. For instance, all of The tank will be set 50 feet the appliance furthest away. pipe will be one inch schedule the second stage piping could from the house, so the first For simplicity, we are going 40 piping.

6 You can size each be piped with one inch piping stage length will be just over 50 to use schedule 40 black iron branch line from there using for the main trunk and inch feet when taking into consid- (Table 4). There are other the same table to determine schedule 40 black iron for the eration the upturn of the lines piping materials that can be the appropriate siae line based branches as long as the mini- to the first and second stage used such as CSST. In this on the distance of that branch mum pipe sizes are met.

7 Regulators. If either copper example, we will use a distance and the Btu/hr rating to be Table 1 Table 2. First Stage Piping between first stage and Polyethylen plastic pipe between first stage second stage regulator: Outside diameter cop- and second stage regulator: Nominal Outside per tubing. 10 psi with a 1 psi pressure drop. Diameter (IPS). Capacities are in 1000 Btu/hr. Capacities are in 1000 Btu/hr. Tubing Tubing Length 3/8 1/2 5/8 3/4 7/8 Length 1/2 3/4 1 1 1/4 1 1/2 . (ft) (ft). 30 309 700 1303 2205 3394 30 2143 4292 7744 13416 20260.

8 40 265 599 1115 1887 2904 40 1835 3673 6628 11482 17340. 50 235 531 988 1672 2574 50 1626 3256 5874 10176 15368. 60 213 481 896 1515 2332 60 1473 2950 5322 9220 13924. 70 196 443 824 1394 2146 70 1355 2714 4896 8483 12810. 80 182 412 767 1297 1996 80 1261 2525 4555 7891 11918. 90 171 386 719 1217 1873 90 1183 2369 4274 7404 11182. 100 161 365 679 1149 1769 100 1117 2238 4037 6994 10562. Table 4. Second State or integral twin stage pipe sizing be- tween regulator and appliance. Maximum capacity of Tubing pipe or tubing in 1000 Btu/hr.

9 Table 3 Length 1/2 1 . Polyethylen plastic (ft). pipe between first 30 762 5225 Tubing stage and second Length 3/8 1/2 5/8 3/4 7/8 1 . 40 653 4472 (ft). stage regulator: Nom- 50 578 3964 10 49 110 206 348 536 1146. inal Outside Diameter 60 524 3591 20 34 76 141 239 368 788. (CTS). Capacities are 70 482 3304 30 27 61 114 192 296 632. in 1000 Btu/hr. 80 448 3074 40 23 52 97 164 253 541. 90 421 2884 50 20 46 86 146 224 480. 60 19 42 78 132 203 435. 70 16 36 67 113 174 400. 80 14 32 59 100 154 372. Think Safety!

10 Fall 2012 Page 3. Two Pound Systems: Two pound systems are installed in place of the sec- performs similar to that of an use than for use in a trunk line an option to the in- ond stage regulator. The appliance regulator. One line due to the single load surge of stallation of larger two-pound regulator pressure regulator can either that individual appliance.). pipe sizes and can delivers two pounds be mounted per appliance, The higher delivery pressure be especially useful of pressure inside or one regulator can serve a allows for the use of smaller in a home where the the structure.