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Undersized Gas lines.

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  • Undersized Gas lines.

    Ok, I have been dealing with undersized gas lines in my area for many years now. I am frustrated with it. Our State Code says that you will size gas properly using the proper charts. What I am running into here is %80 of the homes are undersized. Most of the inspectors here are not requiring a sizing chart and the plumbers are undersizing. We have CSST and Black Iron pipe systems. If you bring 2lbs into a house and put a regulator up in the attic and then run a 1/2 csst line for 75 feet from the regulator to a 100,000 btu furnace. IT IS UNDERSIZED. There is an area here that has a lot of Patio covers and Arbors being built. They are adding gas grills when the arbor is built. The original plumber has stubbed out a 1/2" gas line on the back of the house. It is opposite corner of the gas meter. 126 feet to farthest outlet, gas line coming in is 1 1/4 (black iron pipe system) House already has a 450,000 but load on it. Wants to add a 75,000 btu grill and side burner. In this neighborhood, some plumbers just tie onto 1/2" stub and run from that. According to Charts neither scenario works. If you rob gas from something, it will cause improper combustion. The HVAC furnaces we have today are thin stainless steel. If you crack a heat exchanger, then you have carbon monoxide entering the home. If you have a new home and the carbon monoxide detectors are in the ceiling, then they may not detect the monoxide in time. This can lead to DEATH. I have had 3 carbon monoxide related cases in the last 2 years. Two of these situations someone almost died. In both cases, the carbon monoxide detectors did not go off. I am recommending to all my customers to plug a low to the ground carbon monoxide detector into a wall outlet that has a light on it, and check it often. What your thoughts on this article?
    "don't put that in your mouth, you don't know where it's been"

  • #2
    Re: Undersized Gas lines.

    My thoughts? Makes sense to me. CO detectors are becoming required by inspection here more on both new construction and repair.

    Example: Replace a gas water heater, CO detector required for inspection.

    We don't have as much of an issue where I am about undersizing gas. But I look for more calls as these knuckleheads put in more and more tankless on existing homes without a proper load calculation.

    Comment


    • #3
      Re: Undersized Gas lines.

      So we are not Robinson Crusoe downunder here. Tony AFM will probably read this and pipe in too. The biggest problem we have is that our regulators are so full of their own egos they wouldnt know right from wrong. The old ways are archived and the new generation regulator think they are so wonderful, oh yeah so you want them to do their job too.............!!!!!
      Now we have had some real serious issues here with gas and the regulators just dont get it. They too look for the easy answers so they look good and dont have to earn their keep, literally. Now read up on the CO monitors and you should find that by the time the alarm goes off, if at all, the peoplewill be dead or as good as. Down here we have our portable instruments alarm at 10ppm. These fixed units will mostly go off around 200++++ depending on which side of china they come from. The other issue is the space has to fill with co so the saturation level can be more than this.
      We have found that because we question the Consulting Engineer we are pursecuted and made to want to jump on our own sword becasue they are the experts and we are ????????????. Oh yeah, we are Licensed Plumber Gasfitters. We do all these courses along with an apprenticeship and we dont really know what we are doing.
      So just to add to the BS of the regulators and their incompetence we have a 16yr old in the West who did couple of weeks schooling and is given hois Gas license.
      This is quite a pationate subject of many here. We all agree that the Regulator is asleep at the wheel and has been for so long. Thye work on the premise that 3 deaths in similar circumstances during a winter season warrants an investigation. Forget aboutr the fact that they are useless and DONT do the Job that as PUBLIC SERVANTS we pay them to do.

      We are regulated by those who dont know what they are doing and nobody cares. Blatant examples of non compliance is overlooked becasue there is conflict between the two regulators and teh paperwork required is too hard. Oh dear god in my next life let me come back as an OVERPAID PUBLIC SERVANT. We thuink they should be ashamed that there are people dying becasue they dont do their job

      Comment


      • #4
        Re: Undersized Gas lines.

        Why not go over their thick sculls to the state , with buildings they signed off ?

        That will bring change !
        I can build anything You want , if you draw a picture of it , on the back of a big enough check .

        Comment


        • #5
          Re: Undersized Gas lines.

          Originally posted by Plumbingbyjay View Post
          Point 1 - If you rob gas from something, it will cause improper combustion.

          Point 2 -The HVAC furnaces we have today are thin stainless steel.

          Point 3 - If you crack a heat exchanger, then you have carbon monoxide entering the home.
          Agree with what you say except:

          Point 1 - Only in extreme cases. Most appliances can handle some over and under firing. In extreme cases we find sooting or ignition problems. Lots of appliances have excess combustion air, too. Only a combustion test kit can tell you what is really happening.

          Point 2 - Indoor residential furnaces we have today are aluminized steel, not stainless. People won't pay for stainless steel.

          Point 3 - The majority of modern (90% and some 80%) furnaces have negative pressure heat exchangers - the inducer pulls the flames thru the furnace and pushes the exhaust out. This setup becomes more negative when the main blower engages. Air is pushed into the bad exchanger. CO cannot escape into the household air. Where the cracks are big enough, the main pressure switches do not close, thus no heat/no CO. In transition (between old school and modern) furnaces air is pushed into the combustion chambers (power gas for example) or no forced exhaust is used (atmospheric) or the Amish way - gravity systems. Before the main blower engages the heat exchanger is positive pressure. This is where CO can enter the house. Other factors can influence these scenarios - such as whole house exhaust fans, radon system fans - but this can be used as a general guideline.

          The above info is not to be used to incite flame wars.

          I always tell my customers they need floor and ceiling CO detectors, especially where they sleep.
          ~~

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

          Comment


          • #6
            Re: Undersized Gas lines.

            Thanks for all of the information. I have contacted one of the major suppliers of furnaces here and they are in the process of getting some literature on the dangers of improper combustion. I am not trying to start a war, but am frustrated with why we even have a code, if other plumbers do what ever they want. I try to follow the rules, even if they don't make sense sometimes. If you want to say that furnaces are ok to run on lower gas, than that is fine, then take the tankless water heater. The heat exchanger is copper, sure its forced with a blower, but what a bout an atmospheric water heater, that builds up suit from improper combustion and then the gases don's draw properly. There is a reason for the sizing properly. No one can dispute this. It has been proven. I have been told that what I am saying, is like a lightning strike. Maybe so, but it is a lightning strike that is preventable and lives are at stake. I am contacting the State. Unfortunately, it will bring publicity to me, and that usually means, they then look at me. No one can follow all of the rules. Heck, I don't even understand all the rules to follow them.
            "don't put that in your mouth, you don't know where it's been"

            Comment


            • #7
              Re: Undersized Gas lines.

              When you install a new gas appliance what to the manufacturers directions say about delivery of sufficient gas to the unit? And if the piping is undersized what do you suppose the manufacturer would tell you to do if you gave them a call? I guarantee they will tell you to increase the size of the gas main which if you don't do, you are liable for any problems that may occur down the road and......you void the equipment warranty. Manufacturers instructions trump code unless code is more restrictive.
              sigpic

              Comment


              • #8
                Re: Undersized Gas lines.

                MOM ,can i turn on the tankless now, I need to shower for the late shift ? NO , I need another 30 Minutes for the roast, And the Twins are roasting Marshmellows at the fire pit !
                I can build anything You want , if you draw a picture of it , on the back of a big enough check .

                Comment


                • #9
                  Re: Undersized Gas lines.

                  Originally posted by Plumbingbyjay View Post
                  Thanks for all of the information. I have contacted one of the major suppliers of furnaces here and they are in the process of getting some literature on the dangers of improper combustion. I am not trying to start a war, but am frustrated with why we even have a code, if other plumbers do what ever they want. I try to follow the rules, even if they don't make sense sometimes. If you want to say that furnaces are ok to run on lower gas, than that is fine, then take the tankless water heater. The heat exchanger is copper, sure its forced with a blower, but what a bout an atmospheric water heater, that builds up suit from improper combustion and then the gases don's draw properly. There is a reason for the sizing properly. No one can dispute this. It has been proven. I have been told that what I am saying, is like a lightning strike. Maybe so, but it is a lightning strike that is preventable and lives are at stake. I am contacting the State. Unfortunately, it will bring publicity to me, and that usually means, they then look at me. No one can follow all of the rules. Heck, I don't even understand all the rules to follow them.
                  What you say is true. Sizing of gas lines properly is very important. What I'm saying is that most manufacturers instructions give a range of gas pressures in which the appliance will operate correctly. For example, a newer Lennox furnace at high fire should have 3.5" WC manifold pressure. But, the rating plate says 3.1-3.9 That's proper. That said... It may run on 5", sound like a rocketship, soot horribly, and possibly even split the exchanger. It may also run on 2", but not ignite without rumbling or have delayed ignition. Those 2 examples are not proper, and even dangerous. Just because 'it works' doesnt make it what we should do. What is proper is what the manufacturer's instructions say.

                  I cant stress enough how much a combustion analyzer tells you. Just because you have the proper manifold pressure does not mean you will have proper combustion or proper drafting. Together with the codes and manufacturer's guidelines your knowledge becomes priceless as compared to the guy who just sets and goes.
                  ~~

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

                  Comment


                  • #10
                    Re: Undersized Gas lines.

                    To their credit, inspectors in my area are requiring gas schematic drawings (with sizing and load) before they will sign anything off. My yoga studio (stop laughing, it's the hardest workout I've experienced since my two a days college football late summer practices in the sticky north east) replaced a single unit heater with two horizontal monsters which between them demand almost 400mbtu's and the knuckle head used an existing 3/4" line to the first one and with a 1/2" branch to the second one. When they started to have cycling and spontaneous shut down issues, I suggested they let me rectify the situation. 50' of pipe, a few fittings, two Dormont flexes, a couple of hangers, pressure test w/inspection, and three hours later they were back in business and I had two free six month passes. I love the underground economy.
                    Also, when adding to an existing gas system, an under sized meter has the same effect on appliances as under sized piping.

                    Comment

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