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Natural Gas - new home and big problems

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  • Natural Gas - new home and big problems

    I will try keep this short, but it is complicated...

    New house, 2lb service at meter. NO REGULATOR downstream. How this passed, I don't know. Furnace, Fireplace, Garage radiant heat, BBQ outlet. First sign of problem was furnace cycling rapidly... gas fireplace would run 10 seconds then go out... Now I know it was because they reached high limits and shutdown.

    So... the builder is on the hook and is absolutely going to fix it BUT. House is plumbed with 3/4 flex that is all in the finished walls. 50' from meter to manifold, approx 25 feet to each outlet from there. New gas guy wants to run 1 inch to the manifold, pipe exposed through the garage, install regulator outside near meter... and some other things he needs to tidy up (he says).

    Can I not just get the supplier to put a 1/2 pound reg in the meter and things should work without any extra regulators downstream?

    It is a new house, and I just hate the thought of it looking hacked already...

  • #2
    Re: Natural Gas - new home and big problems

    Furnace is 110K, fireplace 20K, garage heat 75K, no BBQ planned...

    Comment


    • #3
      Re: Natural Gas - new home and big problems

      I would call your gas supplier

      Comment


      • #4
        Re: Natural Gas - new home and big problems

        you need to do a drawing of the piping, with lengths to each appliance, noting the btu of each. contact the supplier of the flex gas pipe and they should be able to tell you if the size is sufficient at the lower pressure. you may need to fax them the drawing. the location of the branches are very important.

        the other, easier option, is to install step down regulators at each appliance and leave the higher pressure alone.
        ~~

        ... it was plumbed by Ray Charles and his helper Stevie Wonder

        Comment


        • #5
          Re: Natural Gas - new home and big problems

          Plumber Punky is correct - the diagram will help calculate if the pipe diameter is adequate. Has the static gas pressure been measured and found to be satisfactory. Also has the gas pressure at any of the appliances been measured during operation. If the pipe diameter is too small then the pressure will drop below what is necessary for operation.

          Comment


          • #6
            Re: Natural Gas - new home and big problems

            Well... here is what we did... The pressure regulator at the meter was replaced with low-pressure (7 inches) and several other deficiencies corrected. The gas man then ran the furnace with the pressure meter on and it didn't drop at all. We did not try run everything at once though.

            Each appliance is roughly the same between 70 to 80 feet. 3/4 throughout, with step down to 1/2 towards the shop heater and BBQ outlet. By his book, we're slightly over length with the 3 main appliances running, and too far over if the BBQ was a factor. His suggestion was to run 1 inch from the meter to the manifold (50 feet) and leave the rest... but after we did the test it seems we've got the volume we need.

            He did not want to put regulators on each appliance, as he wanted to vent them outside (impossible in this case) and did 'like' sit valves.

            So... we're back in business...

            He also rerouted gas lines that were running through my return air... put a hard line into the furnace cabinet... replaced the wiring with armoured... installed an actual fresh-air combustion pipe... and basically redid the whole utility room so the furnace wasn't basically recycling hot air for itself...

            It was a total ****-show, and I will have to say that the 'certified' home inspector that looked at it is a dumb-***. And of course so was the initial installer.

            The gas supplier (Fortis) was happy to replace to a low-pressure reg... offered his opinion that the rest of the system 'looked good'... but said once it's past the meter he couldn't really get involved. Which makes sense...

            Anyway, we have heat - which is good because it got cold here...

            Comment


            • #7
              Re: Natural Gas - new home and big problems

              Originally posted by beyondyourfrontdoor View Post
              We did not try run everything at once though.
              You should have. This is test #1 after all deficiencies have been corrected.

              Each appliance is roughly the same between 70 to 80 feet. 3/4 throughout, with step down to 1/2 towards the shop heater and BBQ outlet. By his book, we're slightly over length with the 3 main appliances running, and too far over if the BBQ was a factor.
              Over length will cause problems. Appliances fighting for fuel, condensing where not designed to, ignition problems, etc.

              His suggestion was to run 1 inch from the meter to the manifold (50 feet) and leave the rest... but after we did the test it seems we've got the volume we need.

              He did not want to put regulators on each appliance, as he wanted to vent them outside (impossible in this case) and did 'like' sit valves.

              So... we're back in business...
              Sooo.... you didnt have the proper calculations done by authority on the subject. You got 'what looks good'. By my CSST chart, assuming you have the 1/2 or less psi pressure (which you do) and a pressure drop of 1/2" WC (which most appliances expect) you will have a capacity of 60,000 BTU on ONE straight-line 80 foot run. You said you need 205,000 BTU. Where's the rest coming from?? Using CSST you would need 1.25 inch pipe to supply 226,000 BTU over 80 feet.

              Good luck.
              Last edited by Plumber Punky; 06-15-2013, 08:57 PM.
              ~~

              ... it was plumbed by Ray Charles and his helper Stevie Wonder

              Comment


              • #8
                Re: Natural Gas - new home and big problems

                We did the calculations, and he suggested 1 inch to the manifold would be spec according to his book. We ran the furnace and got 0 pressure drop at the valve. The reason we didn't do 1 inch right now, is it would have required running exposed pipe inside my garage to the service room. I wanted to test it with the original 3/4 to the manifold as that is all drywalled in. Indeed, we may need to take that extra step...

                I'm not sure which calculations you used... we looked at a book that spec'd 3/4 inch to be approx 200,000 btu at 75 feet... If we need to go bigger, we will...

                Comment


                • #9
                  Re: Natural Gas - new home and big problems

                  Just to clarify, was that with the CSST chart? Or the smoothwall pipe chart? Its a fair diiference
                  No, it's not rocket science, it's plumbing and unlike rocket science it requires a license.

                  Comment


                  • #10
                    Re: Natural Gas - new home and big problems

                    Originally posted by beyondyourfrontdoor View Post
                    We did the calculations, and he suggested 1 inch to the manifold would be spec according to his book. We ran the furnace and got 0 pressure drop at the valve. The reason we didn't do 1 inch right now, is it would have required running exposed pipe inside my garage to the service room. I wanted to test it with the original 3/4 to the manifold as that is all drywalled in. Indeed, we may need to take that extra step...

                    I'm not sure which calculations you used... we looked at a book that spec'd 3/4 inch to be approx 200,000 btu at 75 feet... If we need to go bigger, we will...
                    I used the CSST slide chart with the numbers as above. I think your guy used an iron pipe chart. You don't have iron pipe. And his numbers are way off for .5 psi or less, .6 specific gravity, .5 in wc pressure drop. See here:

                    Irr Supply Centers, Inc.

                    To get 202,000 btu through CSST (the flex you have) over 70 feet it needs to be a minimum of 1" flex with a 1" pressure drop.

                    What you need to do is have the manufacturer of your CSST do the calculation for you now that you have changed the variables. It would have been so much more cost effective to drop pressure at each appliance. It doesn't matter what your installer "likes", it's a matter of what "is proper and works". He seemed to have not wanted to research the proper regulator and wants to use your job as a cash cow. If you have deep pockets and enjoy headaches, the I say go for it.
                    ~~

                    ... it was plumbed by Ray Charles and his helper Stevie Wonder

                    Comment

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