Gas and meter sizing help please
Hello All,
I’m in the process of trying to get the local gas company PG&E to upgrade my meter but I’m running into a few bumps and wanted to get a reality check from y’all.
First off here’s the nameplate BTU requirements of the equipment I am planning to install.
- Wolf-highzoot range 120,000 BTU
- Tankless WH 200,000 BTU
- Boiler for rad heating 200,000 BTU
- BBQ 100,000 BTU
- Gas dryer 22,000
For a grand total of 642,000 BTU.
This neighborhood is all on a low pressure supply which I believe is 1/2″WC. The meter has no regulator it just flows and meters the low pressure gas from the main in the street. The meters nameplate says its a model 250 and has this spec 275CFH@1/2″WC-I don’t know what that means.
The hardline from the street is 1.25″ which necks down to 1″ for a run of about 20′ to the meter where it is necked down again to 3/4″ thru the meter and on into the house.
Here’s what PG&E is saying. That if they replace the 1″ flex line with 2″ flex line and replace the meter with a larger unit that I will get the flow I need and will not have less than a .5PSI drop in pressure. Not changing the 1.25″ hardline from the street seems like B.S. to me?
Does this sound okay to anyone?
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
Oops the title should say Gas line and meter sizing help please.
I've got another problem with PG&E on this. They say they won't 'authorize' putting the new meter in the nice hidden little cubby hole that the original one is in.
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Its not apparently an issue of the new meter fitting they just don't appear to want to install the new one where the old one is? When pressed the rep said it 'would'nt be up to code' if it was installed the box. I asked her what code was that exactly and of course she could'nt tell me... She is referring the matter up to her supervisor..
What they want to do is put the new meter on the wall to the right of the box 12" in from the edge of the vertical stair bit.
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I say that the meter is going to 1. be ugly as sin right up there in front of the house. 2. Going to make this Victorian house look very un Victorian. and 3. Going to obstruct the path to the stairs to get in that door...
We'll see how it goes...maybe I'll have to go to all elec here...
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
Edited 4/20/2008 4:52 pm by madmadscientist
Edited 4/20/2008 4:52 pm by madmadscientist
Daniel, Have them put the new meter in however they are inclined to and after the fact pipe it into the cubby yourself. The meter reader is accustomed to reading it in the cubby so he/she probably won't even notice you moved it unless you wait a month or two to replumb it in the new /original location).I think the saying goes, "it is easier to ask forgiveness than permission"That flex line looks very unorthodox and vulnerable to me. I would definitely hard pipe it if you do relocate the new meter yourself.I too get gas from PG&E and have relocated a meter before without anyone taking any notice. Just do a clean workmanlike job of plumbing it and finish off with a nice coat of gray rustoleum paint over the meter and all the pipe fittings, valves, etc. PGE comes out every ten years or so and gives our meter and exposed pipes a fresh coat of paint. If you paint all your new plumbing work yourself I would say your meter wont attract a second glance.
Karl
Well I hadn't thought about just moving it. I might of already made to big of a stink for them to forget about it...
It seemed to me like the rep was saying that they just didn't want to go thru the extra work of plumbing in the new 2" line to the cubby. I told her that I'd do it and she nearly had a fit. 'EVERYTHING from the street to the valve on the meter is property of PG&E, you are not allowed to touch it..blah blah blah...'
That janky yellow flex line from the riser to the meter is just temp the foundation guys plumber put it on so they could lift-level the house. I have not changed it cause I'm waiting to get the new meter.
Any idea of my BTU requirements will work with the plan they have outlined?
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
PGE would never agree to you touching the plumbing prior to the meter. Like I said it is easier to ask forgiveness than permission. As long as you follow standard practices and plumbing conventions no one will ever notice you moved things. I am assuming it is obvious that one would never want to touch the plumbing upstream of the main pge shut off valve. The guy who comes out and installs your meter will likely never return. If you think/know they are coming out again then wait til they have made their final visit and then relocate the meter.I don't know about the flow restrictions in your main supply pipe and meter but I would just get the biggest one they will install and try it out. I like the previous suggestion of a combination boiler hot water heater rather than two separate units. It is hard to imagine a single family residence routinely requiring the kind of btu consumption you have outlined? Maybe so, but it sounds like a lot of gas for one family.In California I have generally concluded elec is more expensive a heat source than gas but if you are able to add solar panels to your roof and have sufficient sun exposure it might be a better system than gas over the long haul. The system where pge buys back your surplus solar (runs meter backwards) seems to work really well for countless pge customers down here in santa cruz.Karl
PG&E's green book does have a spec for a meter cabinet. Or at least it used to. You may have to modify yours to comply. If you want to follow the rules.John
The spot I gussied up down in San Juan Capo similarly had the meter right there for everyone to see. I, too, had it swapped out for a bigger one, but in the same spot.
The landscape designer solved the problem with a nice bush.
I just had to move a meter because of a storage shed I built around it. They don't want the meter in any kind of structure. They want it exposed to the open air so if there is any leakage the gas has no way of accumulating.
I'm not positive but my city inspector and my wife who works in the energy industry said the oversight for this stuff has changed. Believe it or not it is because of Homeland security. The potential for anything blowing up was looked at and they thought it best to put all of it under the energy companies.
The feds put jurisdiction under the energy companies.
You could just hide with a bush afterwards.
That makes sense except for places like here in SF where all the neighborhoods with row houses have the meters in the garages. This is basically outside its just in a cubby under the stair landing.
I was just told that nat gas is lighter than air so as long as the cubby is vented at the top and bottom (I would think it would be fine).
Yea hiding it with a bush is an idea but its still going to be directly in the way of the stairs down to the bottom floor of the house.
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 understand the pita it is but I had no choice. I offered to ventalate the room but they just wouldn't listen. They wanted it outside. Period. At my cost.
In the end I let it go. If there is even the slightest chance of it being dangerous I'll comply. But at first it made me angry. It just took a while to get used to the idea.
The crew that moved it was a nice bunch of guys. A made them two batches of cookies.
1 cubic foot = 1,031 btu's or 1 therm
275cfh = 275 cubic feet per hour
275 cubic feet = 283525 btu's
In other words it will run about 1/2 of your full demand
Normally you won't use all of those at the same time----- kicker------ water heater & boiler will run at the same time in the winter.
If you had a combo boiler/water heater under 300K you would be fine.
Yours is the first low pressure distribution system that I have seen.
“The world is a dangerous place, not because of those who do evil, but because of those who look on and do nothing.†—Albert Einstein
My radiant expert is pushing me towards a combo boiler-WH.
If I did that do you mean that the existing meter would handle it and the existing 1" pipe?
It would be cheapest for me if the 1" pipe would handle it and they could just pump the hardline up to 1" and put a bigger meter in the cabinet. I plan on running a 1" line from the meter to the rest of the house with 3/4" branches running to the appliances.
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
Here's a good rule of thumb for sizing. This is in CFH, but these numbers are figured from a meter that has a regulator.
Length in Feet
Pipe Size
10
20
30
40
50
60
70
80
90
100
1/2
174
119
96
82
73
66
61
56
53
50
3/4
363
249
200
171
152
135
127
118
111
104
1
684
470
377
323
286
259
239
222
206
197
1-1/4
1404
955
775
663
588
532
490
456
428
404
1-1/2
2103
1445
1161
993
880
795
734
688
641
605
2
4050
2784
2235
1913
1696
1538
1413
1315
1234
1165
2-1/2
6455
4437
3503
3049
2703
2449
2253
2096
1966
1857
3
11412
7843
6299
5391
4778
4329
3983
3705
3476
3284
Pipe Size
125
150
200
250
300
350
400
450
500
550
1/2
44
40
34
30
28
25
24
22
21
20
3/4
93
84
72
64
58
53
49
46
44
42
1
174
158
136
120
109
100
93
87
82
78
1-1/4
358
324
278
246
223
205
191
179
169
161
1-1/2
536
486
416
369
334
307
296
268
253
241
2
1033
936
801
710
643
592
551
517
488
463
2-1/2
1646
1492
1277
1131
1025
943
877
823
778
739
3
2910
2537
2257
2000
1812
1667
1551
1455
1375
1306
“The world is a dangerous place, not because of those who do evil, but because of those who look on and do nothing.†—Albert Einstein
Hi Bill and thanks for the table,
So my math says that I need ~622CFH for all the BTU's.
Is that table from the meter into the house? Or from the street to the meter?
If those are low pressure #'s then dang I will need at least a 1.25" pipe for the 20' run from the street to the meter. Then after the meter my 1" pipe idea isn't going to be big enough..Wow, I don't think I've ever seen residential gas lines bigger than 1" inside a house...
Of course if that table is only for higher pressure gas then all bets are off and I'll need even bigger lines...yowza
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
Table is low pressure from the regulator.
My house has a 1.25" main cause my furnace is at the opposite end of the meter.
When I did a friends I had to install a 1.5" main----- same reason.
“The world is a dangerous place, not because of those who do evil, but because of those who look on and do nothing.†—Albert Einstein
Okay that makes sense so I can consider everything to be 'after the regulator' because the entire system is at .5"WC
Now PG&E says the line from their main to my prop line is 1.25" and this line is about 20' long. That gives me 955CFH at that point. Then they want to switch to a 2" line from there for the ~20' to my meter. Does that make sense to you?
From the meter its about 60' to the farthest away appliance-gas bbq. To be safe should I do 1.5" from the meter thru the house?
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
As long as you are installing a new meter, you might consider also installing an excess flow valve. I believe these are required in Alameda County whenever there is a sufficient amount of remodeling is done. In Contra Costa County, an earthquake shutoff valve for the whole house is required when the building is sold or remodeled - along with excess flow valves on each appliance. Thus it is likely that the requirements will be tightened over time in your county. Besides, additional shutoff protection is probably a good idea in any event. It will probably be a lot cheaper to install a shutoff valve when a new meter is being installed than it would later on when the meter is in place. (Last I heard, the going price for having a plumber work on the gas meter was in excess of $120/hr.) I think an excess flow valve runs around $100 or so, the earthquake shutoff valve is probably $20 to $30 more. Having both excess flow and earthquake shutoffs, like is the requirement in Contra Costa County, is probably overkill.
>>>>>Now PG&E says the line from their main to my prop line is 1.25" and this line is about 20' long. That gives me 955CFH at that point. Then they want to switch to a 2" line from there for the ~20' to my meter. Does that make sense to you?<<<<<<<
Yeah it makes sense, we size gas lines from the furthest point to the source.
“The world is a dangerous place, not because of those who do evil, but because of those who look on and do nothing.†—Albert Einstein
This has been a very interesting topic. As usual, the message starts at the very practical, and ends up at the very scientific. I am referring to the chart. Uniform Plumbing Code says : For a maximum of 50 feet and a maximun of 466 CFH the pipe size is Half inch. Just one observation, the code says 3/4 of an inch for all freestanding appliances, and I am referring to the BBQ. Also, some pipes before the tee connection gather the BTU of the other appliances and therefore require a larger size. Again, I admire the chart, it is educational. If I get too scientific, I apologize.
I'm not sure I'm following you.
What code says that at 50' of 1/2" you can 466 CFH?
“The world is a dangerous place, not because of those who do evil, but because of those who look on and do nothing.†—Albert Einstein
I think he's reading the chart wrong. 50' of 1/2" pipe according to the chart is only good for 73CFH.
Had the PG&E rep and her boss out to the house this am. Turns out the meter with the cap I need is a commercial meter and won't physically fit in the space. The biggest residential that will fit in the space is rated at 350CFH so I either gotta cut way down or go with a commercial meter.
He did suggest an alternate spot for the meter that will be a lot less obvious from the street and not screw with the Victorian looks of the house.
I can't believe what they are going to charge me though...If I uncover the existing gas line/valve and dig a trench all the way to the new meter spot ~10' I have to go under the driveway curb and SWMBO is going to have to pry up some of those bricks she laid-boy am I glad we listened to you guys and did them in sand not mortar-and I have the house line brought to the area of the new meter they are going to charge me...~$3500!!!
$3500 is highway robbery for what they are doing. I have to pay thru the nose for the privilege of buying much more of their product....where's the logic in that?
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
The code is Uniform Plumbing Code . Plumbing a House by Peter Hemp page 170 Taunton Press. The table reads Natural Gas Maximum Capacity of pipe CFH Feet 50 CHF 466 pipe size 1/2 inch.
That's strange, I wonder what year that book came out.
UPC doesn't cover gas pipe anymore, now covered by the UMC.
My 1994 UPC book has gas sizing, I'll dig it out & see what the charts in have to say.
“The world is a dangerous place, not because of those who do evil, but because of those who look on and do nothing.†—Albert Einstein
B149 gives me 95,000 btuh at 50 feet at 7"-14" w.c. based on a 1" pressure drop.
Can you explain a bit more about the pipes before the T gathering the btu's of the other appliances?
I am planning on running a 1.25" main line into the house and then branching off from that with short runs of 3/4" line to the appliances. Will a setup like that solve this issue?
All my big gas appliances spec a 3/4" gas line. But then the biggest I could find a flex line is 5/8" id? The guy at the real hardware store looked at me like I was crazy for asking for anything bigger? I've got a 200,000BTU tankless heater that has to suck gas thru a 5/8" line? Does that make any sense??
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
Take a look at Taunton's "Code Check: Plumbing" book. It has the tables and an explanation of how to use them to size gas pipes to multiple appliances.
-- J.S.
Take a look at these for your tankless connections.
http://www.dormont.com/dmc/uploadedfiles/res/ResourceCenter/tankless-gass-connect-spec.pdf
Example: The farthest appliance from the meter is 75 feet . Another appliance branches off at 50 feet. This branching off is caused by putting a tee. So now you have 75 feet + 50 feet. That is a total of 135 feet. The pipe between the tee and the meter must be larger than 1/2 inche because it is going to supply two appliances. If you look at the chart under 135 feet and the combined CFHof the two appliances, it will give you the size of the pipe. Chances are that 5/8 (like you say) is o.k. From a practical point of view, we install pipes just a tiny larger if in the future they decide to have additional appliances.
I too had never heard of such a thing until a couple of years ago when I was offered a job (didn't take) of running a gas line crew in downtown Vancouver BC. They were replacing all the low pressure gas lines in that part of the city. The steel pipes were about 6 inches in diameter and they were running the new high pressure lines inside the old pipe. In the front of each house the old pipe was broken out (about 4 feet) and the house connection was made and torpedoed to the new meter which now had a reg.
Roger