1″ residential gas line excessive?

Hello All,
Planning out some of the mechanicals for the ‘new’ place. Right now there is a one inch gas line that comes into the meter which is necked down to 3/4 inch thru the meter and out to the rest of the house. The meter is set up to handle 1″ pipe without any adaptors. All of our gas appliances require a 3/4″ line. That’s the tankless water heater, the house heater, the gas clothes dryer, the kitchen stove. In the future I also plan on a nat. gas bbq and fire pit.
To my way of thinking a 1″ line run to some central location to a valved manifold which then runs 3/4″ lines to the appliances would be the way to go. I don’t think I’ve ever seen a 1″ residential gas line. Would this be excessive? I’ve also never seen a valved manifold setup for gas.
Daniel Neumansky
Restoring our second Victorian home this time in Alamdea CA. Check out the blog http://www.chezneumansky.blogspot.com/
Oakland CA
Crazy Homeowner-Victorian Restorer
Replies
I don't think I've ever seen a 1" residential gas line"
MS,
That's pretty much standard here in WI.
WSJ
It is not uncommon.
The thing that is more common is undersized lines and ustomers ccomplaining about appliance performance
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The thing that is more common is undersized lines and customers complaining about appliance performance
Amen
Beer was created so carpenters wouldn't rule the world.
I think you will find that all your appliances only need 1/2inch but "might" need 3/4 to get there.
What goes into your meter doesn't mean anything. It all depends on pressure. The pressure going into your meter is maybe 100 times higher than what is coming out . Here in British Columbia we have a choice of gas pressure within a house 2 pounds or 1/4 pound so that makes a huge difference in the pipe sizes within a house. In Onatrio we always put in 1 inch to cover any add ons later.
Manifold systems are used quite often here in BC and sometimes are very usefull, whether it is in your situation only the shadow knows.
roger
Actually Roger all my appliances spec 3/4" as a min. Sure they will work off of 1/2 line but how well? I changed out the 1/2" line to my 36" pro-style stove to a 3/4" line and noticed the difference when I have a couple burners going at the same time.
I don't that here in the SF bay area in CA that they run high pressure lines to residences. In the event of an earthquake they don't want a 100psi natural gas line to rupture and turn into a flame thrower...if a 3psi line ruptures its not great but not as bad.
Daniel Neumansky
Restoring our second Victorian home this time in Alamdea CA. Check out the blog http://www.chezneumansky.blogspot.com/
Oakland CA
Crazy Homeowner-Victorian Restorer
I've had a gas licence for over 30 years and almost all house appliances have 1/2 inch fittings. A few have smaller 3/8. Restaurants usually are 3/4inch fittings. Just because the appliance has 1/2inch fittings doesn't mean you can't run a 3/4 inch line to it and reduce it at the appliance.
Just for the fun of it, phone the gas utility and ask about the pressure in the street. I can almost gurantee you will be surprised. If you had only 3 pounds coming into your meter you would need hellish big gas lines 10-12inches in the street to be able to supply enough gas for the rest of the neighbourhood.
roger
This seems like a silly thing to argue about but have you ever installed a Wolf 36" stove ? to know for sure that they don't require a 3/4" line? Have you installed a high powered tankless gas water heater lately to know that it doesn't require a 3/4" line?
You know what I do believe that the gas lines in this neck of the woods are that big.
Daniel Neumansky
Restoring our second Victorian home this time in Alamdea CA. Check out the blog http://www.chezneumansky.blogspot.com/
Oakland CA
Crazy Homeowner-Victorian Restorer
In the new construction houses I do the HVAC contractors install 3/4" hard pipe for everything, and I believe they put a drip leg at every appliance. Hate to say it, but I'm sure they would run 1/2" in some areas if they thought it would work. I think flex gas line doesn't give as high of flow rates so may need to be upsized. The Gas Company installs 2 pound meters. If you look at the meter it should have a model/cereal plate on it that also states the CFH rating. To me "it looks old" is not a very difinitive way of doing things... Still, at least in my area, the gas company is very anxious to help. Wish the elect co was so cooperative. Again, there is a formula for converting your total BTU load to the CHF load requirement for the meter. A quick Google brought up this page: http://www.propane-generators.com/natural-gas-chart.htm
When I order gas meters for the houses, I have to state the pound rating of meter required and tell them what the gas appliances are in the house: ie range, H/W, fireplace, 2 furnaces, or whatever the config is. The HVAC contractors are required by the inspections department to mark their piping with the pound rating where it is stubbed out for the meter, so for me there isn't much thought that is needed to go into ordering a meter except that I can't do it until the final mechanical inspection is complete.
Personally I'm not a big proponent of DIY gas piping for obvious reasons. I guess it would be OK as long as the installation holds maybe a 15# test for 24 hrs and it is inspected. Gas leaks in newly installed gas piping is not uncommon.
Question for all: Does gas piping need to be graded: ie 1/4" per ft or whatever, so that moisture doesn't collect in pipes?
Gas doesn't have to be graded. Anything that isn't supposed to be in the system is supposed to be caught in the drip leg/dirt pockets.
roger
OK - thanks.
Whoa! don't get your nickers in a knot Mad. I'm not arguing anything. If you re read my messages I have always talked about the appliance itself about having 1/2 inch fitting. FITTING. NOT the line going to it. I would never talk about the exact size of gas line going to any appliance without knowing the BTU rating of all the known and POSSIBLE FUTURE appliances, the BTU rating of the appliance in question, pressure of the system, whether the line is a manifold system or in series and if in series where in the series is the appliance in question located and all measurements.
As an aside, if you are thinking of adding all those future gas appliances, depending on the information mentioned above, you might need to upgrade your 1 inch line from the meter. Also if you are concerned with earthquakes you should consider putting in a wobble switch on the gas line. I happen to live beside the same fault line you do but 1500 miles north.
roger
"I think you will find that all your appliances only need 1/2inch but "might" need 3/4 to get there."Have you ever read the instructions for installation that come with the larger gas ranges like Viking?I did AFTER I had a customer complaining that his burners barely made heat and the gas guy told me I needed a 1" line for such a large unit.
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Oh hell, here we go again. The majority of household appliances come with a 1/2 inch fitting some 3/8inch. This is at the appliance NOT the pipe which goes to it. You can have a 2 inch pipe going to it but must be reduced to the fitting at the appliance which is usually 1/2 inch. If by chance you have an appliance with a 3/4 inch fitting doesn't mean that you must have a 3/4 inch line going to it. The size of the line going to any appliance must be sized taking several things into consideration. You could have a 3/4inch fitting in the appliance but only need a 1/2inch line to feed it. The average gas range runs about 80-90KBTU and even some bigger commercial looking home ranges run up to 150KBTU and that's with 6 burners and 2 ovens. Top burners use far more than the oven/broiler. Could some ranges be even bigger, sure but I haven't seen them. A 1/2inch line at 7-14 inches ofWC can accomodate up to 227KBTU's depending on lots of factors but according to the schedule 227K is max. 3/4inch max is 474K BTU again depending on factors. Now why would a manufacturer put a 3/4 inch fitting on a range where 1/2 would suffice? It could be that they want to look like a restaurant stove or maybe the gas valve is adaptable to propane where on a big stove needs more than a 1/2 fiiting because the propane schedule lists it slightly lower inpressure so it needs more volume. In our gas code (maybe not in yours but maybe) whatever we figure the gas sizing to be we are allowed to drop in one size before it get to the appliance. I can't remember whether it's the final drop or within 6-8 feet. Something like that
Restaurant stoves are considerably bigger. The burners are bigger than any commercial looking home range even though they might look the same. Plus restaurant stoves can have salamanders,broilers, grills all of which are higher in BTU. Gas piping going in restaurant kitchens are very big because not only are they serving the range but also deep fryers and other stuff.
Actually I'm one of those guys who always (well almost) reads installation manuals. Whenever I have instructed apprentices I drill it into them to always read the manual. I'm not sure whether or if I have ever installed a Viking. It is not a name that come to mind but when I install I first double check to see if I got the right range, gas or propane, and then I check the BTU rating. To me, the brand is almost irrelevant. I guess in a nutshell, the manufacturer can put whatever size fitting it wants on the appliance but it is me and the code which decide the supply line.
Regarding the 1inch line: 1inch has a max capacity of almost 900K. That's almost 1 million BTU's. Again, without knowing any dimensions or loads I would think that you had a possible pressure problem and that by increasing to 1inch gave you more volume but I'm only speculating.
Many jobs are undersized because a lot of gas guys can't properly size correctly (or additions have been made) yet even extremely undersized system seem to work okay because piping systems are designed to operate correctly with every appliance going full blast and we all know that it rarely if ever happens . I used to service gas stuff and in the far majority of cases whenever there was a problem as you describe it was a pressure problem, usually a regulator.
As a thought, there are places which have gas pressure which is lower than normal and THAT can make a difference.
roger :)
Thanks for fleshing that out. the first post you made that I was replying to did not make it clear that you had any experience in this.The worst case I had trouble with was indeed a restaurant range installed in a residence. The owner has a chain of restaurants so that explains a lot. It cam with no fitting, just a 1" black pipe threaded for a fitting.The original installer just made up the fittings to connect to the original house supply line. Then came the complaints of inadequate heat supplies. It had six burners, two ovens, and a grill. When the guy from the gas company walked in on the service call, his first comment was, "There is no way your line will give you enough BTUs for all that hook-up!"
Then he asked for the book on the appliance, got his book on flow and volume, etc out and figured things. Said that at the distance it was running, a 3/4" would always be a little short of enough. He ran a 1" flex. That was the basis for my Q to you - not to be argumentative, but to point out what I had to learn the hard way - that something like this should be planned based on the intended usage and not on prior experience or general statements online. So now I always make the customer decide what the appliance will be early on in the project
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
No worries Pif. Communication, verbally and face to face is a wonderfull thing with our body language,nuances and inflextion in our voice. The written form is devoid of all that and many things are misconstrued and/or misunderstood. Lucky we can use CAPITALS, quotation marks and the best of all the happy face ;)
Learning things the "hard way" is usually the best way because you never forget it. It's too bad because some of that stuff was so friggin hard and SO embarassing at the time. In fact, it is even now when I think of some of them.:)
with love;)
roger
I was planning on a salamander broiler in my kitchen remodel , but the DW nixed that one---- also nixed the commercial gas deep fryer I was planning on building in
If you don't stand behind the troops, why don't you try standing in front of them. Bumper sticker
what do broiled salamnders taste like???Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
Like wet chickenIf you don't stand behind the troops, why don't you try standing in front of them. Bumper sticker
well if a broiled salamander tastes like wet chicken, what does a boiled one taste like?
better not be slimey
WTB soggy..Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
Don't you find it amazing that if you put that stuff in a commercial restaurant you would need a huge exhaust hood yet if you put it in a home you don't (that I;m aware of) More exhaust gasses than a furnace, and worse gasses because of impingement. (hot flames on cold pots creating nasties)
roger
So true, but I was prepared for that at my house.
Here is my hood.View Image
& here is the fan that provides the suckingView Image
If you don't stand behind the troops, why don't you try standing in front of them. Bumper sticker
Duuude that looks like it totally sucks!!!
Sorry long day at work
Daniel Neumansky
Restoring our second Victorian home this time in Alamdea CA. Check out the blog http://www.chezneumansky.blogspot.com/
Oakland CA
Crazy Homeowner-Victorian Restorer
Well I cook with two setting HIGH & offIf you don't stand behind the troops, why don't you try standing in front of them. Bumper sticker
More exhaust gasses than a furnace, and worse gasses because of impingement. (hot flames on cold pots creating nasties)
what is impingement, I have never heard of it?
In no way am I doubting you, just never heard of it.
any idea how ugly this issue this is for indoor air quality? Like the unvented furnace ,oops i mean, stove doesn't matter.
Edited 6/12/2007 12:18 am ET by bobtim
Impingement is when part of the flame touches an object.
In this case, the burner flame touches the pot, and the flame cools down. When that happens, incomplete combustion can occur, producing carbon monoxide.
Hah! good question. I think the word impinge means to hit something and in gas fitting "we" use it when a gas flame strikes something that is cold and causes some poisonous gases like carbon monoxide and soot due to the temperature drop around the flames causing improper combustion of all the surrounding gases near the flame. Soot is usually and indication of impingement. Usuallly the object doesn't stay cold for very long and the "impingement" stops and of course the nasties go up the chimney..........................................if you have a chimney. A cold pot of water takes a lot longer to warm up than a piece of sheet metal in a furnace. Even when the flame is burning efficiently there is a certain amount of nasties but it makes a person wonder about inspectors concerned about some gas chimney problems when there is ahuge unvented range in the kitchen. A conundrum to say the least but then again isn't life that way also.
I see Rich another Canadian already answered it.
roger
Edited 6/12/2007 9:48 am ET by roger g
roger g: At last someone that understands that gas has to be calculated, it can't be eye-balled!, when you also say that you read the manuals you become my hero!. "May the force be with you"................................
"If all else fails, read the the directions"
Soooooooooo, should you use total developed length or the load of each branch? :)
Great thread everyone................
On a hill by the harbour
You have to add up the total load on the system in btu's, that will give you the mimimum size that you will need to supply the load, [this depends on local codes] if the meter dosen't have enough cubic feet it will have to be changed. You work back from the most distance fixture and add up the btu size until you get back to the meter. This is a good general answer, best that I can do.....................................
"If all else fails, read the directions"
Not bad.:)
We can do it total length of pipe and load, or by individual branch load. On commercial it may mean the difference between welded or threaded fittings.
Our utility often sizes meters to 80% of connected load. Works ok unless it is a restaraunt, Jan 1st, and every applaince is running. Sometimes troubleshooting just plain sucks.
rich1: War story; years ago a company I was working for had a "salesman" sell a warehouse lots of roof top units, when they were turned on they wouldn't keep running, NOT ENOUGH GAS! The company had to eat the $8500.00 to change the 1/2lb system to 2lbs. This is one of the reasons I'm an advocate for calculating before install. Lots of luck......................................
"when all else fails, read the directions"
Years ago a bunch of us guys were discussing venting on high efficiency furnaces and we couldn't understand why we couldn't vent another way. We already knew some of the reason why the manual stated and it made sense but there were some other installs that we thought would be alright. I decided to get on the phone and call the manufacturer and speak with their tech branch ( I've called a lot of mfg over the years and solved a lot of problems).
I got a really good engineer on the phone who was very helpfull (tech guys usually are) and he gave me the best answer I have ever heard and I have used it many times. He said "Roger, the install you suggest might work, and probably would work but we can prove our way works through calculations and emperical data. Can you prove yours.....................in civil court!" Meaning of course some disaster had happened and the venting was suspect
roger
Can you prove yours.....................in civil court!" Meaning of course some disaster had happened and the venting was suspect
A half dozen years ago there was a judgment against a hvac installer for creating and failing to remedy a situation that caused carbon monoxide poisoning of two teachers. The CO levels weren't high enough to kill them outright just a little under the weather, but over the course of two years created permanent mental imparement that ended their careers. The judgement was for a handful of millions. It would have been cheaper to do it right the first time.
Good building
Beer was created so carpenters wouldn't rule the world.
Mine is 1.25" main then reducing tee's as pick up appliances.
It depends on demand & length of run with pressure factoring in.
Here is a quick over view on how to size.
http://www.propane-generators.com/natural-gas-chart.htm
If you don't stand behind the troops, why don't you try standing in front of them. Bumper sticker
mine is also 1 1/4 for about the first 30' in the house then as it hits appliances downsizes to 3/4 by the end of run. larry
hand me the chainsaw, i need to trim the casing just a hair.
You determine pipe size by the serviced applinace's BTU per hour and the length of the run to the appliance. Search the web - you can probably find a table that specifies diameter as a function of pipe length the BTU requirements for an appliance. Froom the total system load is derived the CFH (cubic feet per hour) which dictates your meter size. If you are adding a gas appliance you may need to look at your meter too.
Thanks everyone for the advice. I'm going to check the BTU req. for all the appliances and see if I can get the gas company to upgrade the meter-the one thats there looks really old. I'm stuck with the 1" main line unless I want to tear up a bunch of concrete all the out to the sidewalk...
One inch main line to manifolded 3/4" branch lines it is.
Daniel Neumansky
Restoring our second Victorian home this time in Alamdea CA. Check out the blog http://www.chezneumansky.blogspot.com/
Oakland CA
Crazy Homeowner-Victorian Restorer
I wouldn't worry about the meter, it probably has atleast 40psi of gas on the street side, & 6 to 12" on the water column on your side.
I have done plenty of gas systems that have a 1" connection at the meter & ran 3" gas pipe to the equipment.If you don't stand behind the troops, why don't you try standing in front of them. Bumper sticker