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pex tubing

Rob Blair
Rob Blair Member Posts: 227
Just make sure that they did a heatloss and can back it up with their product. Many times staple up has a hard enough time heating spaces because of windows, carpet, etc. Just make sure that they can provide what they sell.



  • [Deleted User]
    pex tubing

    I'm ready to run pex tubing in my house. I'm doing a staple up ,i've been told too used 1/2 pex and do a double run in each bay.The other company said too used 7/8 pex and do a single run in each bay. Who's right or which way is more efficiency?it's a close system
  • big willy
    big willy Member Posts: 92
    I have

    never seen someone use 7/8 tube for staple up. I tcould be done with large transfer plates but why fight it. Its hard enough to get 1/2 inch pex to do turns in a by 3/4 could would be a bear. Also if you drill a set of holes at one side of the bays you can run a tube town and the inside and back out the outside hole. this lets you go to the end farthest from the uncoiler and pull loops of tube into each bay and work towards the uncoiler. If you use one tube in each bay you will be threading tube and that takes forever and with 3/4 tube its gonna be a hard row to hoe. Use 1/2 inch pex 2 in each bay with heat ransfer plates. It works for me and everybody else. Dont re invent the wheel. Good luck.
  • [Deleted User]

    Rob,you were close. it was radiant company.They said using 7/8 pipe carry more btu per foot then a 1/2 line .but i was reading in the wirsbo hand book, it said :the only advantage to using 7/8 tubing over 1/2 tubing is a lower pressure over the same loop lenght larger diameter pex will not deliver more heat per sq ft of radiant panel
  • Dave_4
    Dave_4 Member Posts: 1,405
    Size of PEX verses BTU output

    Modern Hydronic Heating 2nd Edition has a graph on page 331 addressing this issue.Upt o about 90 degree circulating temp the difference between 3/4 and 3/8 inch tubing is insignificant at 120 degrees the difference in BTU/hr/swft is 28 for 3/8 and 32 for 3/4 (difference of four) 1/2 and 3/4 about difference of about 3 BTU/hr/sqft.

    Advantage of larget PEX can run longer loops

    Carl VanderPutten
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