Natural Gas Line Size And Volume Used

[Glanceblamm]

My Natural gas line is 1" black iron (pretty much the standard size) Which I reduced down to 1/2" at a handy stub by the furnace in the intrest of running copper tubing (1/2 OD-3/8 ID) for gas supply to ventless wall heaters. I actually added two different headers or mainifolds with one 1/2" supply valve on one header and two of the supply valves on the other.

Two of the heaters are up and running in my new to me house (a 30,000 btu & a 20,000 btu )with considerations for adding another 10 or 20k unit to this 2,700 ft home.

My Question Is to ask if I can get by with splicing into 32' of the 3/8" ID tubing that I installed for heater #2 (which would reduce tubing cost by quite a bit along with being very handy) or if I should invest in new tubing and start back at the third supply valve that I installed for the addition of heater #3 ?

My concerns of doing a splice would be getting enough volume of the natural gas to supply two heaters through the same line. This might be like trying to drink a beverage of your choice through a cocktail straw but then again, maybe the line pressure would stay the same regardless of the demand?

Your thoughts would be appreciated. I had this setup in my old house (three heaters) and chose to run a separate line for each which placed the shut-offs very close to the 1" supply header.

[Dixie Dude]

According to my calculations 32' of 3/8" copper tubing will only handle 21,000 btu's without having significant pressure drop (low flame).  This can be dangerous if the flame goes out and can fill the house with gas, unless you have safety pilots on the heaters.  I would suggest installing iron pipe at that distance, or the very least 5/8" copper for 91,000 btu's.

[Glanceblamm]

Thanks Dixie Dude, this is what I needed to hear as I don't know how to do those calculations. hint

Heater #1 "the 30,000 btu" is running on a short section of the 3/8 tubing that is around 12' long.

Heater #2 is the 20,000 btu on the 32' section of tubing. I reckon that this section of line is actually around 29'-30' because I squared off the turns with the tape measure just so I would make sure to have enough line to do the job with no splicing.

To extend the black iron piping for heater three (have not purchased it yet) would be very doable. My outlets Lowes\Menards actually have a type of flex hose for natural gas\propane that would remind you of hydrolic hosing but yet is more supple. The OD is at least 1" and like the hydrolic, you have to put your own ends on it. I may look at this again but have never worked with it.

The signs of low gas pressure (as said by the manuals on these heaters) would be to have yellow flame while running. My two new ones are both burning and even, brilliant, blue. These heaters come with the safety's that you are talking about (read thermacouple on the pilots) along with built in 02 sensors. The house has it's own C/O detectors along with fire alarms of course.
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More Unrelated To This Topic Info On A Ventless Wall Heater

I believe in them. We ran them for 15 of 18yrs in the old place without a problem to include a C/O alarm or even a headache. When the power goes out they can be great.

You Do Not install the ventless heater in an area such as a bedroom or bathroom. They need to be in a larger area and I prefer the (Intersections) between the larger rooms, hallways and such where they can easily draw and circulate the air & heat.

The wall mounting is via bracket at the top & clearance bushings at the bottom. This holds the heater app 1" away from the wall. Your side clearance from potential objects needs to be 8" with the front clearance being 36". This is very generous as the heater simply does not get hot at the sides or the back.

The heater does have it's own thermostat with auto shut off but is set via a dial of 1 through 5 instead of dialing in a specific temperature like you would do with your main furnace. This is not a hassle as there is usually a handy wall thermometer in most households to include the readout on the thermostat of the main furnace. My two heaters are currently running at a setting of just under 2 to achieve our target of 65-68degrees throughout the house. This is comforatable with the right amount of humidity in the air and it can get cold & dry here so we do run a humidifier in the winter time.

My worst enemy (as of last year) was the Power Company. Our letter last March said that the representitive determined that our digital gas meter had quit working in January!...Their expert made this assumtion based on the amount of gas that a furnace required to heat the residence in comparison of what others were spending on their heating. The fact was that we did not run our main furnace at all last winter and I told them just that. We had a full basement with good windows and would keep that basement door closed making it easy for a 20,000 btu unit to heat that entire area to 70 degrees at the low setting of 2.4
This, in turn, heated up the flooring of the main living area very nice making it easy to maintain 68 degrees with another 30,000 btu unit that was on the main level and situated at the intersection of two hallways that had good heating access to the bathroom & bedroom & kitchen on one end and the living room, dining room, and another bedroom on the other.

We fought them tooth & claw as we had accumulated a $450.00 credit on our billing. Our best argument was that they could not prove that the meter actually quit working, or had slowed down, or whatever when they changed it out. They still siphoned $200 off that credit despite my best trick of sicking my wife on them ...I was looking forward to doing battle with them this year but then we moved as said.

We do have the same company at this residence and I do expect a battle. It may even be worse as we have a wood burning insert type of stove in the fireplace and I do have a chainsaw & access to wood in this rural area. I also made it a point to learn how to read their state of the art, fool proof, gas meter along with the power co having the knowledge that we are the same customers and are back if they try this again.

Sorry for the rant..
P.S. We have spent $475 tax included on the two heaters to include lines and all of the fittings. Sounds like a lot but they will pay for theirselves easily over this winter. Less than a full winter "the wife argues" based on what people we know paid for heating in just a couple of the bad months last year.

[Dixie Dude]

I have a central forced air heating system with a 60 gallon gas water heater.  The heat uses hot water through what looks like a car heater with the air blowing across it to heat the house.  It is 90% efficient but requires the large water heater.  Anyways I am an engineer with a gas utility company.  Hope I helped.  I personally like the black iron (actually it is steel) piping better than any other.  If you ever have it hidden in a wall or something and try to nail something like shelves or something on a wall with the gas piping, it is hard enough to deflect a nail or screws.   Hope I helped.

[Glanceblamm]

Hope I helped.

Very much thank you as I am leaning towards an extention of the black iron. Not much I can do about getting it in a finished wall with low attic overhead but will keep the lenght of the tubing in spec for sure.

[jiminpa]

also some building codes/states will not let you use copper for gas lines.

[bobg]

  The gas company sucks. I had a new house built. The gas supply line came out on the left rear of the house. Called the gas co. to install the meter. They told me no way. Meter needs to be on right rear of house. My son-in-law and i were going to install a new line. I could have bought all the black pipe and fittings for about $65. I had to wait a week for my son-in-law to get time to pick the parts up for me. In the mean time i get a letter from the gas co. With a bunch of forms that had to be filled out and signed by a certified plumber. I hired one. Less than 45 minutes he is done and hands me a bill for $337.35. The only things in the house using gas are the furnace and cook stove. My first two bills were over $200. Called the gas co. and read the meter to them. Was told oh my we must have made a mistake. Haven't had a gas bill over $65 since. Sorry for the long rant. It just upset me.
      bobg

[nessmuk101]

I understand your rant, but you just had a new house built and that bill for $337.35 is about 0.0001% of the total cost of your project.  Any one with a pipe wrench can hook up gas pipe but who is responsible when your new house blows up?  Who is the first to be blaimed?  Now you have a chain of paperwork to go back on and the gas company is sure that the job was done right.

As a retired gas company employee, you would be supprised at some of the unsafe things people will do with gas lines in their homes, and then get mad when they are red taged and the gas is shut off until the problem is fixed.

[deersniper]

I have 31 years with a natural gas company and I will say there is no cutting corners when dealing with this fuel. It is a very safe and reliable source of energy when installed correctley in your home. People that don't use the gas companies for their home installation piping better make sure their using a certified plumber that knows what he is doing. Too many times I have been to customers homes where a plumber did a hatchett job and customer was smelling gas, if you ever deal with gas fitters that are not employed with the gas company make darn sure that they pressure tested their work upon completion.

[Glanceblamm]

if you ever deal with gas fitters that are not employed with the gas company make darn sure that they pressure tested their work upon completion.

Good Post.

My own experience came from 30yrs in the thermoplastics industry and involved plant air, steam, vinyl acetate, and polyvinal chloride and line size ranging from 7/16 copper to 10" stainless. Had lots of experience with all types of fittings as pressure vessles had to be taken down and purged out (with fittings) for PM (or preventive maintenance work) and then reassembled after preforming these task's. To pressure test this equipment goes without saying and I became very confident of my work holding up to the required 100psi range. In my experience, if a leak did show up, it would be at the 80 psi range.

When dealing with the natural gas in my home I took the same care as at the workplace and reckon that my lines would hold up to 100psi even though I was only going to subject them to around 4 oz of pressure.
This lower pressure does not matter as I still did the pressure check when done as you have a lot at stake.

If you smell natural gas or propane in your home the good advice by my provider is to get out of the home without turning any lights on or off and to report it immediately and Not from the phone in the house.

If you have some experience and the smell of the gas is not overwhelming, you can fill a spray bottle with water and a shot of dish soap and spray down the fittings at the appliance and bubbles will readily show once you have found the leak. At this point you may be able to isolate that appliance or line via a shutoff valve. You can then call the proper contractor to make repairs or do it yourself if experienced and confident in making the repairs at hand.