# Help w/ gas pipe size calc



## mdshunk (Mar 13, 2005)

Help me with this gas pipe size calc. I want to add a Rinnai/Noritz water heater, if my pipe size is adequate. The present equipment that uses gas is a 250,000 Triangle Tube boiler, a 6 burner Wolf range, and a regular 4-burner freestanding range. I'd like to replace an existing 80 gallon quick recovery electric water heater with an on-demand water heater. It might take two units to replace this 80 gallon one, I think. Anybody care to tackle gas the pipe size I need coming in? I think I have a 1" presently.


----------



## KillerToiletSpider (May 27, 2007)

One inch is to small for what you have now.


----------



## mdshunk (Mar 13, 2005)

KillerToiletSpider said:


> One inch is to small for what you have now.


I'm nearly certain of that, but if I have to upgrade to bigger than a 2" it's going to get prohibitively expensive and I won't go with the on-demand water heater(s).


----------



## KillerToiletSpider (May 27, 2007)

mdshunk said:


> I'm nearly certain of that, but if I have to upgrade to bigger than a 2" it's going to get prohibitively expensive and I won't go with the on-demand water heater(s).


1½" is probably all you need. Unless you have more than three bathrooms that are used at the same time I don't think you need more than one tankless heater, just get one capable of 12 GPM.


----------



## Double-A (Jul 3, 2006)

Are you on a high pressure system or a 1/2 ounce system? How much 1" do you have before a branch. 

Gas sizing is all about total btu's deliverd per pipe length. One way to "enlarge" the size of a gas system without using a larger pipe is to deliver gas in a loop. In other words, you run a full sized pipe to the end of the line. This will in effect, feed the system from two ends, allowing less drop to the far fixtures and over all shorter distances.

If you get more serious, get a plumber involved and possibly the gas company for a larger meter. Doesn't do any good to upsize the gas system of the gas company can't deliver that much gas to it.


----------



## mdshunk (Mar 13, 2005)

I already talked to the utility about getting gas in the pounds, but they won't run high pressure in a dwelling here. I've got to stay in the inches of water column. It looks like I'm upsizing pipe. Their gas guy today told me that I need a 2 inch meter.


----------



## coolmen (Mar 25, 2006)

you need to draw a map from the meter to the furthus appleance.map out the distance to each and every appliance,size pipe, and how much BTU is needed for eachline to appliance,and total ammount of btu. you dont want to take wild guess at this, a google search will help you with this.


----------



## PP Plumber (Jul 29, 2008)

Depending on hot water demand in gpm will determin the size or no. of units you need. Depending on the area you are in will determin the gpm of your shower heads and faucet flow, jacuzzi tub flow etc. This will then give you the total BTU draw you will require to feed the on-demand unit (s) that you chose. From there you can upsize the line as needed or run a new line from the meter all the way to your unit(s). This way you dont need to redo your whole system. Get your total cfm (cubic feet per minute) draw and TDL (Total Developed length) to find your pipe size from the meter.


----------



## cal (Jan 31, 2008)

How is this post different from the other DIYer's who get directed by a Moderator to anothe site? No hire a plummber post.


----------



## MALCO.New.York (Feb 27, 2008)

cal said:


> How is this post different from the other DIYer's who get directed by a Moderator to anothe site? No hire a plummber post.



How is this different?????

MDSHUNK, although a condescending smartaleck at times, is one of the most respected, most PROVEN Trade Professionals here on this sight. He adds more to this sight than most.

This is Contractor Talk, a sight where *Contractors* SHARE ideas, know how, information and Industry news.

He is CLEARLY in the Industry and therefore will be treated as such. There is NOTHING that he can *steal* from here, injuring the industry, as a DIYer could.

Having said this....See the difference?


----------



## 22rifle (Apr 23, 2008)

cal said:


> How is this post different from the other DIYer's who get directed by a Moderator to anothe site? No hire a plummber post.


Because mdshunk is not going to steal from another trade, break the law, or mess with stuff he should not be messing with. That's why.


----------



## cal (Jan 31, 2008)

How hypocritical, I guess instead of paying my plumber to do all the pipe sizing on the last remodel I did I should have asked for free advise. I'm a professional too and don't ask the other trades to do something they get paid for because i don't like them asking me. We all have a living to make.


----------



## MALCO.New.York (Feb 27, 2008)

cal said:


> How hypocritical, I guess instead of paying my plumber to do all the pipe sizing on the last remodel I did I should have asked for free advise. I'm a professional too and don't ask the other trades to do something they get paid for because i don't like them asking me. We all have a living to make.


You have been here one day and you are in the position, upon a throne, to pass judgment.:laughing::whistling:w00t::notworthy:shutup:

And did you mean advi*c*e or did you mean to be advised????


----------



## 22rifle (Apr 23, 2008)

cal said:


> How hypocritical, I guess instead of paying my plumber to do all the pipe sizing on the last remodel I did I should have asked for free advise. I'm a professional too and don't ask the other trades to do something they get paid for because i don't like them asking me. We all have a living to make.


Don't be stupid.

When you get your plumbing license then your example applies. Until then, it just makes you look like a petty .


----------



## mdshunk (Mar 13, 2005)

cal said:


> How hypocritical, I guess instead of paying my plumber to do all the pipe sizing on the last remodel I did I should have asked for free advise. I'm a professional too and don't ask the other trades to do something they get paid for because i don't like them asking me. We all have a living to make.


I'll share a secret with you. I have a master plumber's license, mostly to demonstrate how ridiculous the licensing process is in my area. I'm not doing any plumbing or gasfitting, nor do I intend to. I'm working up a plan mostly for budgetary reasons. If it can be done withing a certain budget, it's gonna get done by a plumber who not only has the silly license, but knows what he's doing. I approach any project with my own fair measure of due dilligence, much as I would recommend any GC do. From my standpoint, as an electrician, I find that an educated customer is a joy to work for. When I hire any sub, I've normally got all the potential approaches researched, and I just talk with them about my preferred one and they take it from there. I'd hope any plumber would appreciate that. Contrary to popular belief, not every tradesman you'll ever hire has your bottom line in mind. Plus, I simply find it enjoyable to learn something new every once in a while.


----------



## 22rifle (Apr 23, 2008)

mdshunk, don't waste too much time worrying about a guy who has made 4whole posts on this forum, 3 of which were trying to stir up crap.


----------



## cal (Jan 31, 2008)

Where do you get one day? I guess if you have a difference of opinion the way to solve it is to attack. It appears if one has a low post number you are not allowed to ask a simple question. I do not have to attack another person to feel good about what I do. Many of us have licenses in multiple trades(over 40 years as a electrician).


----------



## mdshunk (Mar 13, 2005)

cal said:


> Where do you get one day? I guess if you have a difference of opinion the way to solve it is to attack. It appears if one has a low post number you are not allowed to ask a simple question. I do not have to attack another person to feel good about what I do. Many of us have licenses in multiple trades(over 40 years as a electrician).


Yeah, good for you. For now, you're just a prick stirring up trouble. You're allowed to stir trouble here only as long as you've contributed something helpful in equal measure. That's one of those unwritten rules I felt obligated to explain. :thumbsup:

Think about it like this... You're sitting at a bar and some guy you've never seen before sits down next to you bitching and complaining and otherwise being a jerk. You're either going to whisper to the bartender to get him out of there or you might just choose to tab out and leave. On the other hand, if that person that sat down next to you, bitching and complaining, is known to you and you've had decent conversations in the past, you're more likely to tolerate his strange mood today and let his comments roll off.


----------



## MALCO.New.York (Feb 27, 2008)

Hence the "Throne" of which I spoke Cal......Until you have paid, you can NOT play.

Now you owe us TRIPLE! And I appoint myself Accountant of your Trust.

Start payin'.


Until then, you are not allowed to be a prick as I, Shunk, 22 Rifle, USP45, RonThePlumber, Mickeyco, GrumpyPlumber and the rest are know for being.

(WOW!! How many of us pricks are plumbers????)


----------



## Grumpyplumber (May 6, 2007)

cal said:


> How is this post different from the other DIYer's who get directed by a Moderator to anothe site? No hire a plummber post.


*I highly doubt MD will do the actual gas himself, unless it's legal where he is..in that case I'm sure he'll have it inspected per local code.*
*He's a longtime contributer, over 8,500 posts.*

*This isn't some guy who just joined two days ago and has nothing but threads asking info on how to do work he shouldn't be doing.*
*People know him here, he knows what not to do and it's his own home...not an illegally profitable venture.*


----------



## Double-A (Jul 3, 2006)

OK, keep it civil folks. 

Cal, we share ideas and how-to all the time on this site. Part of knowing how to do one trade and work around them is knowing how their trade works and some of its requirements. This question is not out of the scope of things. MD earns his living in this field.

Yes, we're hypocrites at times, but that is the nature of the beast. It ain't perfect but it works in its own quirky way. We shoot down the DIYer's for more than one reason, not the least of which is to drive traffic to our sister sites, but also to keep this forum free from the same 4 mundane questions. Although, that part seems not to be working, because we still get the "how much should I charge" thread at least once or twice a month in a slow month.

We offer what we offer to MD because he has shown an ability to appreciate his own limitations and has been a long standing member. We're not the easiest lot to get along with, but we're loyal if nothing else. Helping is what we do, even if someone doesn't like the answer we think is best for the situation.

I respect your willingness to point out this hypocrisy and the way in which you did so. It usually winds up in a pie fight, but sometimes it garners some respect. 

When we set a higher standard for ourselves and raise our expectations of our industry, we have to live up to those same standards. The only way we're going to get converts is to be an example. We must respect each other, even if we don't respect what the other is doing. That is the basis for professionalism. 

<takes of his moderator hat>

HIRE A PLUMBER MD!

<puts his hat back on>

Now, can we all just get along?


----------



## Ron The Plumber (Oct 10, 2006)

Ok I'll be nice, MD hire a plumber damit.


----------



## mdshunk (Mar 13, 2005)

Ron The Plumber said:


> Ok I'll be nice, MD hire a plumber damit.


Legally, in every sense of the word, I am a plumber. I'm still not doin' the work, though. :thumbsup:


----------



## Ron The Plumber (Oct 10, 2006)

Just kidding :laughing:


----------



## neolitic (Apr 20, 2006)

I calculate that the 120" pipe 
in your other thread will supply
plenty of gas for you! 
And all of Harrisburg as well.
:laughing:


----------



## Grumpyplumber (May 6, 2007)

*Cal, (if you haven't completely quit the forum)...*
*I respect your stance...look through my posts and you'll see I'm ordinarily quite the prick with DIY info...ESPECIALLY with newer members with few posts.*


*Online forums have become a harbor for hacks & illegal handymen to attain free info from the very plumbers they take work from...I completely agree with you.*
*But...this is an exception (never thought I'd say this).*
*This isn't some new guy who hopped in to ask how to install a boiler, he's looking into it for his own home.*


----------



## donchange (Nov 15, 2007)

If it possible run a new pipe from gas meter to the W/H -just put one more T.


----------



## mdshunk (Mar 13, 2005)

donchange said:


> If it possible run a new pipe from gas meter to the W/H -just put one more T.


I think that's exactly what's going to happen. That, and changing out the meter itself. 

One interesting thing I learned about these on-demand water heaters. I visited the supply house for reading material on the Rinnai, and they questioned me. The salesman asked, "any particular reason why you want Rinnai". I told him that I don't really, but I figured they were all the same. They happened to handle Rinnai, Noritz, and Takagi, all in stock. He said that Noritz has the most GPM for the dollar spent, and they make many of the parts that are in the Rinnai and Takagi units anyhow. I think I'm going the Noritz route if I can confirm that what he told me is true. I was able to confirm that, from them, you can get the best value (GPM's per dollar spent on the unit) by going with Noritz. I have been unable to confirm thus far that Rinnai and Takagi use many Noritz parts inside.


----------



## KillerToiletSpider (May 27, 2007)

mdshunk said:


> I think that's exactly what's going to happen. That, and changing out the meter itself.
> 
> One interesting thing I learned about these on-demand water heaters. I visited the supply house for reading material on the Rinnai, and they questioned me. The salesman asked, "any particular reason why you want Rinnai". I told him that I don't really, but I figured they were all the same. They happened to handle Rinnai, Noritz, and Takagi, all in stock. He said that Noritz has the most GPM for the dollar spent, and they make many of the parts that are in the Rinnai and Takagi units anyhow. I think I'm going the Noritz route if I can confirm that what he told me is true. I was able to confirm that, from them, you can get the best value (GPM's per dollar spent on the unit) by going with Noritz. I have been unable to confirm thus far that Rinnai and Takagi use many Noritz parts inside.


It's true.

I install Takagi because no one here handles Noritz.


----------



## 22rifle (Apr 23, 2008)

Noritz seems to be built better inside. That is just a visual observation so hardly worth the effort it takes to type it.


----------



## donchange (Nov 15, 2007)

You can check also Navien (new brand from Korea -navienamerica).We install Rinnai .


----------



## Pete M (Dec 10, 2007)

mdshunk said:


> Help me with this gas pipe size calc. I want to add a Rinnai/Noritz water heater, if my pipe size is adequate. The present equipment that uses gas is a 250,000 Triangle Tube boiler, a 6 burner Wolf range, and a regular 4-burner freestanding range. I'd like to replace an existing 80 gallon quick recovery electric water heater with an on-demand water heater. It might take two units to replace this 80 gallon one, I think. Anybody care to tackle gas the pipe size I need coming in? I think I have a 1" presently.


Gas is funny. In some states plumbers run and size gas pipe. In other states you need a mechanical license. In any case, you're not allowed to oversize any branch or the main. You really need to have the appropriate person actually walk the job and do the load calcs based on the developed length to the farthest fixture from the meter and BTU demand of each branch. It's no big deal if your meter can handle the total load.


----------



## 22rifle (Apr 23, 2008)

> In any case, you're not allowed to oversize any branch or the main.


code cite for that?


----------



## Pete M (Dec 10, 2007)

22rifle said:


> code cite for that?


Sorry, I'm not ducking your question but I've been out of the biz too long. I ran gas for about 20 years in California as a plumber. A sure way to fail an inspection was to needlessly oversize a gas line, hide a union fitting, install a fitting with a plug in it or use a thread protector fitting as a coupling. You also couldn't do anything that an inspector could perceive as "providing for future use." You could upsize your pipe, but only enough to carry the current demand load. You couldn't run a 2" pipe for a stove, for example, (that's what I meant). That additional sizing would constitute "future use."


----------



## 22rifle (Apr 23, 2008)

Pete M said:


> A sure way to fail an inspection was to needlessly oversize a gas line, install a fitting with a plug in it You also couldn't do anything that an inspector could perceive as "providing for future use."


Wow. Which code was this? I thought California went by the UPC and that sure ain't in the UPC.


----------



## Nick1123 (Jul 26, 2008)

Cal... you will find there is alot of guys on here who know what they are talkin about... i perfer to take advice from the guys who post fewer times all around the same time per day/ week.... these guys are the ones who are actually working in the feild and earn what we call A LIVING.... some guys are on here non stop all day and all night and are just addicted to fighting with DIYs... check out the posts... someone who posts all day everyday def is not working in my book... As the moderator always says this site is for shareing knowledge between trades so that we all know whats going on from every aspect of our projects. this does not mean if we are not licensed that we go do the work.. it simply means we are to gain the knowledge of whats going on to make sure our licensed guys are doing what they are supposed to be... basicly 20% of posts on your thread will be extremely useful and the other 80% will be things like... Call a licensed plumber.. caugh caugh... not to mention any names


----------



## mahlere (Aug 6, 2006)

i have full faith that if MD does it, not only will he do it with Rigid electrical conduit...but he'll overcharge himself so as not to destroy the plumbing industries profitable pricing...

for the GC's who are bitchin'...it's one thing for you guys to do the work in your own house...it's a different ballgame to illegally do the work for a paying customer...and if you can't see the difference, well, that just explains why specialty trades generally disdain small GC's...but that's just my $0.02 pissed into the pot to stir it up a little.


----------



## mahlere (Aug 6, 2006)

Nick1123 said:


> these guys are the ones who are actually working in the feild and earn what we call A LIVING....


they are called carpenters, plumbers, electricians, etc...but most aren't contractors...


----------



## Grumpyplumber (May 6, 2007)

Nick1123 said:


> Cal... you will find there is alot of guys on here who know what they are talkin about...


*You're definitely not one of them, I'm still unsure why you come to the plumbing forum after openly lying to attain info, then coming back to throw it in everyones faces.*


----------



## MALCO.New.York (Feb 27, 2008)

Grumpyplumber said:


> *You're definitely not one of them, I'm still unsure why you come to the plumbing forum after openly lying to attain info, then coming back to throw it in everyones faces.*


OUCH! Even my nuts hurt on that one!!!!!!!!!!!!


----------



## Joasis (Mar 28, 2006)

Ok...enough already. Negative posting will end now.


----------



## JamesNLA (Jun 2, 2006)

It's been a little while since I have been around here, but as I started reading.....this site is still funny as all hell. Marc, if you still need info on this topic I understand what you were asking and talking about. I have some new info on the world of tankless as I take it over!! he he!!


----------



## CA PLMBR (Sep 13, 2008)

Hey guys,
I agree with Double A. You need to calculate your system. If your going to be changing a system from a tanked to a tankless on-demand you are surely going to require more gas because the on-demand heaters require more btu in short periods. I have installed about 150 of the Takagi on-demand heaters and they had 4 burners in them. They worked somewhat like a boiler in that they have a programmer. If the flow/demand is low the heater will fire up one or 2 burners. If the flow demand is high it will fire up 3 or 4 burners to accommodate the demand. The cool thing about the programmer is that it doesn't fire the same burner off first, hence you don't get uneven carbon on the same burner. It will fire the next in sequence and so on. The only issue I had with the heaters I installed is that the high limit breaker would trip shutting down the unit. Sometimes the actual temp sensor (which has a trip) on the combustion piping would trip for no good reason. This happened on probably 8-10 of the units I installed. On a few it was a one time push the reset button. On the rest I had to replace the heater. You also have to consider venting requirements at least for the Takagi that I used. We had the Takagi rep out and he specified the b-vent piping. I'm trying to remember the catagory. I know it was stainless steel with a hub on one end with rubber gaskets. Obviously because with the added pressure of the draft fan you would need better sealing than a conventional unit. As far as the effectiveness of the heaters they worked great. Had no issues as far as not getting enough hot water. I was installing these in 3 story condos and I believe I had from 3/4" to 1 1/4" services running to them. Only because the units had banked meters on one end and had runs of like 200'. The units closer to the banks obviously were the 3/4". I don't know about the Noritz never used them. I know that Bradford White has a dual venting system (shared intake/exhaust piping) that's pretty convenient if you have to relocate the heater someplace where you did not have a good source of intake air. Hope any of my rambling helps.


----------



## CA PLMBR (Sep 13, 2008)

Pete M said:


> Sorry, I'm not ducking your question but I've been out of the biz too long. I ran gas for about 20 years in California as a plumber. A sure way to fail an inspection was to needlessly oversize a gas line, hide a union fitting, install a fitting with a plug in it or use a thread protector fitting as a coupling. You also couldn't do anything that an inspector could perceive as "providing for future use." You could upsize your pipe, but only enough to carry the current demand load. You couldn't run a 2" pipe for a stove, for example, (that's what I meant). That additional sizing would constitute "future use."


Hey Pete,
I currently work in SoCal. The way we engineer our systems on new construction jobs is to accommodate options. A big thing with the builders now is to have option upon option upon option. This just helps the builder to tailor the home to the homeowners budget and taste. So, for the plumbers and other trades we size assuming an option on (gas, water, waste) then cap off if the option is not chosen. This allows for later cutoff dates and does not require the re-engineering of the whole system. I do not know what code you are referencing but that is no where in the code that I can find nor have any inspectors ever made a case against it. Maybe it was just a preference of the company or municipality where you were working.


----------



## semprasuper (Jan 29, 2009)

mdshunk said:


> Help me with this gas pipe size calc. I want to add a Rinnai/Noritz water heater, if my pipe size is adequate. The present equipment that uses gas is a 250,000 Triangle Tube boiler, a 6 burner Wolf range, and a regular 4-burner freestanding range. I'd like to replace an existing 80 gallon quick recovery electric water heater with an on-demand water heater. It might take two units to replace this 80 gallon one, I think. Anybody care to tackle gas the pipe size I need coming in? I think I have a 1" presently.


 Is the operating pressure 6 in w.c. or are you operating on a 2 psig system. Unless the line serving the boiler is a homerun to properly size the line you have to know the entire btu load the line is serving. Most residential tankless water heaters are 200,000 btu or less so you would need to know that amount also. Information needed will be operating pressures, btu loads and length of runs to appliances. Example on 6in w.c. you can run a 200,000 btu appliance up 95 feet on 1 inch id pipe. On a 2 psig system you can run the same appliance the same distance with 1/2 inch id piping.


----------



## plumber1a (Dec 30, 2008)

Now back to the original job; In many cases we relocate the heaters nearest the gas meter and run separate but shorter gas to them as in most cases it's easier to run water piping to and from the heaters than gas and don't forget the cost of stainless steel venting if your indoors.


----------

