Any plumbers out there (Natural Gas)

rick-l · 10-27-2006, 09:12 AM

How does this work? I didn’t know I would need to consult an aero engineer.

I want to add a 45,000 BTU heater out in my garage. I thought wow 18 feet of ½ inch pipe and it would be fat city. Then I started to do a little research.

What I have now is a 120,000 BTU furnace and a 30,000 BTU water heater 63 feet from the meter. Looks like a 42,000 BTU cook top and 50,000 BTU barbeque about 40 feet from the meter were added after the original installation. The heater would be 73 feet from the meter.

The gas line comes through the wall into the house on about two feet of ¾ inch pipe and immediately goes into a 1” pipe that goes across the basement to the furnace with all the other stuff tapped in.

Going to the local (for someone else) codes and gas sizing charts on the Internet it seems like what I have now (the main 1” pipe) is too small anyway.

Is what I need to do is replace the 55 feet 1” pipe with 1 ¼ “ pipe? Why does it seem strange that it come into the house on ¾” pipe? Am I missing something? Does going to the 1 ¼ “ pose any problems I am overlooking?

nineoneone · 10-27-2006, 10:38 AM

you don't have to move up in size, you could stay with the 3/4" what might happen is the pressure on the main line which is so many inches of water column may need to be increased do to the added equipment. In other words by the time the heaters in your garage comes on the pilot light on the hot water heater will extinguish. Have the gas company check your local pressure and go from there. hope this helps.

rick-l · 10-27-2006, 11:33 AM

Quote:

Originally posted by nineoneone
the pressure on the main line which is so many inches of water column may need to be increased do to the added equipment.

Seems like the regulator on the meter is not intended to be messed with. If you don't restrict the useage on any appliance the demand could be anywhere between 0 and 300 cubic feet per hour.

TSNAPCRACKLEPOP · TSNAPCRACKLEPOP's Garage

lets sit down and have a cup o' joe and a cigarette and think about this for a minute.

nineoneone · 10-27-2006, 12:30 PM

Quote:

Originally posted by rick-l
Seems like the regulator on the meter is not intended to be messed with. If you don't restrict the useage on any appliance the demand could be anywhere between 0 and 300 cubic feet per hour.

This is why I said call the gas company. If you continue to add equipment to any one line the pressure set by the gas co. needs to be adjusted at the regulator or you run the risk of not have enough gas to carry the pilots. All pilot gas systems are designed to operate at a certain pressure and when (because the pilot valve is set at factory) you add more equipment it drops the pressuse down the line. Same with water lines start with larger lines and branch off with smaller ones but in the case there is always a leak....pilot lights.......... if all the equipment comes on at about the time and its not been increased, very low flames , takes forever to heat and you will lose pilot lites due to low pressure. Ask me how I know......... now if this is just additional equipment meant to operate in emergency situations you may not need it. I'm not saying pilots will consume the gas pressure all at once but when everything starts to operate.

JeffO · 10-27-2006, 12:51 PM

I just spoke with the gas company about this exact thing. He said that the main gas line is a pressurized line and flow is restricted by the size of the meter. The regulator knocks pressure down to a usable household need while the meter dictates the volume that is allowed to flow. I am starting with heat,hot water,and stove with a future possible grill, patio heater and fireplace. He said call me and we put in alarger meter. Also remember water can not be compressed like gas can be so comparing the two is wrong.

MotoSook · 10-27-2006, 12:55 PM

I'm getting ready to leave the office for the day so I can't run calculations for you, but the problem you may have, and the problem the code is likely trying to prevent is pressure drop in your line. In other words, the service regulator (at the house meter) is set at 11 ounces of water column, and with all your appliances running, the long and winding 1 inch line system may result in less that the required pressure at the appliance furthest from the service regulator.

The meter and the regulator at the meter each have a maximum flow capacity. If you exceed the meter's capacity you and the gas company will not be happy. You will not be able to, nor should you adjust the regulator. Your domestic appliances operate within a range of operating pressure. Increasing your service pressure to make sure you have enough pressure at the individual appliances during high flow condition may require you to install a second cut regulator at each appliance. I don't think you will want to do that, and I don't know if the distribution company will come out and install a new regulator-meter set for home owners with just a friendly phone call.

I'll run some calculations for you...and we can have fun with gas. :-)

(If you guys want to have fun, assume 1000 Btu/cf. Then play with Darcy's equation. Use 3 or 4 equivalent pipe length for each elbow or tee in your system. Figure out the volume flow rate from the Btu values he listed...then start crunching numbers)

MotoSook · 10-27-2006, 12:57 PM

Just read JeffO's post, and looks like the gas company is more than happy to bring you a larger meter-regulator setting. I guest that makes sense...chaching!

TSNAPCRACKLEPOP · TSNAPCRACKLEPOP's Garage

fluid dynamics too

JeffO · 10-27-2006, 02:55 PM

Yankee Gas said no problem to replace meter with no charge to consumer. As a matter of fact I am getting the the line installed from the road to the house , with regulater, meter installed at no charge as long as I start using LP gas within 60 days.

BGCarrera32 · 10-27-2006, 05:34 PM

At least in the Midwest where I am, the old houses have 1/4 psi gas metering where you'll likely find old black pipe, and 2 psi metering on the new stuff where they run flexible unannealed copper tubing. You can snake the copper tube just about anywhere and its much easier to use, but the smaller diameters create more pressure drop over the run, hence the need for 2 psi supply. You can have your meter upped to 2 psi metering and you'll get away with just about anything you're hooking up with copper (sans some 100' run and humongous furnace). What I am not positive on is if you need a 2 psi to 1/4 psi pressure reducer on all the applicances now or if they are already there, so in a nutshell I would do as nineoneone said and...call the gas company out.

rick-l · 10-30-2006, 10:07 AM

I went out and looked at my gas meter and it says 250 C.F.H @ 1/2" diff.

I assume that sets the limit as to what I can connect to it.

Since it would cost me a small fortune to have a pro replace all my 1" schedule 40 with 1 1/4" I guess the warm garage dream is over.

Brian 162 · 10-30-2006, 06:09 PM

I used to work for a natural gas utility (Consumers Gas) until de-regulation in Ontario. Anyway the standard gas meter was a 225 meter. If your meter says 250 cubic ft. per hour that means the max. load on that meter is 250 cubic ft. on a LOW PRESSURE service. Low pressure main delivery is roughly 11 inches water coloumn. If your gas service has a regulator before the meter then you have an intermediate or medium pressure service. That means that the max allowable gas flow of your meter is 500 cubic ft. per hour. I am not sure of your gas codes down there but I think your meter is fine. Maybe upsize your gas pipe to 1 inch from the meter to your 1 inch line in the basement.

Brian

TSNAPCRACKLEPOP · TSNAPCRACKLEPOP's Garage

did you make the news yet?

legion · 11-02-2006, 12:23 PM

Hmm...since I upgraded from a 30 gallon water heater to a 40 gallon water heater...I've noticed that I get less hot water in the winter than the summer.

rick-l · 11-02-2006, 02:26 PM

Quote:

Originally posted by TSNAPCRACKLEPOP
did you make the news yet?

As in a loud bang followed by smoke and flames? No I think I gave up.

An alternate plan would be replace all the 1 inch gas pipe with 1 1/4" pipe, hook up all the crap including the garage heater and then call a plumber when it didn't work (300 CFH needed, meter supplies 250). This might be alot cheaper than having him cut and thread pipe. Besides screwing pipe together sounds like fun.

JeffO · 11-02-2006, 02:41 PM

they don't use black pipe here in Ct anymore, its all flexible stainless. A lot cheaper in labor, offsets higher material costs. Call your gas company's customer service and get all your answers, then put heat in that garage of yours!

Don Wohlfarth · 11-02-2006, 03:27 PM

Call your gas company and see if they will set a 2 psi meter next to the existing one. Then you can run a copper line to your garage for future appliances. You'll need a regualtor at each appliance. Really no big deal.
I started using 2 psi systems 10-15 yrs ago to supplement existing black pipe systems. The labor cost on installing black pipe may be 10 times, or more, that of a 2 psi system.