Really, really, really, big pipes in hot water heating system

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by jtraxler, Jan 28, 2007.

  1. jtraxler

    jtraxler New Member

    Jan 1, 2007
    I have hot water gas heat in a 1920's house. Most of the original cast iron pipes in the basement are exposed and some of them are absolutely huge (5" diameter). My understanding is that the original system used gravity rather than electric pumps to circulate water through the house so the extra volume was required.

    As my heating bill continues to climb (it's getting cold in New England), I'm wondering if it is worth a long term investment to address what I expect is a real waste of energy. I figure I am paying a ton of cash to heat much more water than I need to since it just sits in the pipe. I also expect that motors in the system are working extra hard to move the high volume of water.

    What I want to know is how to determine the best "ROI" for one of the following:

    Option 1: Replace the large pipes where possible (do not rip open walls, etc.)

    Option 2: Insulate the exposed pipes (none are insulated).

    Option 3: A little of both?

    Option 4: Do nothing. The extra energy required is nominal.

    Anyone ever dealt with this situation and determined the best course of action? If I do anything, I do not really want to wait 20 years for the pay-back on my investment.


  2. hj

    hj Moderator & Master Plumber Staff Member

    Aug 31, 2004
    Cave Creek, Arizona

    #1 and #2. The smaller volume of water will give you a higher circulation velocity, so the radiators will heat more efficiently.
  3. Sponsor

    Sponsor Paid Advertisement

  4. jtraxler

    jtraxler New Member

    Jan 1, 2007

    Any sense of how to get a rough calculation on the savings? I figure replacing these pipes is no small cost and if it just going to cut 10% off my bill, it will probably never pay for itself.

  5. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Sep 2, 2004
    Retired Systems engineer for defense industry.
    New England
    A friend of mine had a similar system (if I remember correctly), and when he had it analyzed (Canada is stricter on this sort of thing), his ancient system was actually quite efficient. He left it alone. Can't say for sure about yours.
  6. Plumb or Die

    Plumb or Die Plumbing Instructor

    Jan 13, 2007
    Plumbing Instructor
    Southern BC Canada

    Depending on the piping system, this large diameter thing you have going could be really efficient. One component to check out might be the pump(s). If this was an older conversion from a gravity system, the pump(s) might be a big power draw. I'd get a pump dude over to have a look. Make sure its the appropriate gpm, etc., Do the pump curve thang. Insulation's a good thing too.
Similar Threads: Really really
Forum Title Date
Plumbing Forum, Professional & DIY Advice Is this mess really how it's done?? Dec 21, 2016
Plumbing Forum, Professional & DIY Advice A really tough vanity to install a lav faucet on. Feb 26, 2016
Plumbing Forum, Professional & DIY Advice Having trouble getting Original Toto Flapper THU092-7, really, seal gasket alone would be fine Feb 10, 2015
Plumbing Forum, Professional & DIY Advice HELP! I’ve Fallen, and I can’t.....OK not really....., but I do need help! Dec 11, 2014
Plumbing Forum, Professional & DIY Advice Water hammer issue, really need high level professional helps Dec 9, 2014

Share This Page