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LP and Gas in same building.....

kcopp Member Posts: 4,261
I was lurking over at OTT on the gas section and stumbled across this post on oil/Ng/ LP in the same flue.... Tim posted this.

"Oil with NG okay

Oil with propane okay

However you can't have natural gas equipment and propane equipment in the same dwelling other than portable equipment like a propane gas grill."


 I have never run across this before. So if you have an apartment w/ the upstairs w/ LP heat/ gas range and the downstairs w/ Nat. gas boiler this is a no no? Even if they do not share a chimney/ vent? I could not find this in NFPA54..


  • Bob Harper
    Bob Harper Member Posts: 986
    get it in writing

    When I hear this type of information, the first thing I think of is what code, standard or regulations are they referencing? Often, such information can be traced back to regulations promulgated by gas utilities and not written in the codes, whether at the state level or local ordinance. Having said that, you can also have local ordinances. Very, very few contractors I've ever met actually own copies of the major codes and standards they are held to. Now, just when you thought you knew of every code and standard you are held to, another pops up. For instance, in the course of a recent case in Delaware, it was 'discovered' that the contractor, a chimney sweep, had a care of duty breach when he failed to perform a level I inspection as defined in NFPA 211. Now, 211 has been adopted as the local code for chimneys, vents and fireplaces in only a handful of communities nationwide. However, in De. the State Fire Marshal had adopted it in its entirety in 2006. Therefore, the Superior Court of De found the contractor had a duty to act and breached that duty when he failed to perform this basic level inspection, which the court held most probably would have revealed the fire hazard caused by illegal aftermarket glass doors on a factory built fireplace, which caused an unfriendly fire that damaged 5 units and cost $1.25 million.

    There are some 'jurisdictions' where LP gas is not allowed in basements. In others, it can only be used in attics if the heating equipment sits in a pan that actually has a drain to outdoors. These are utility regs. and not in building codes for the most part. Around Philly, PECO used to publish a thick book of their version of their requirements over and above the state gas and mechanicial codes. About 10 years ago, they revoked it and now rely on the ICC codes as adopted in the Pa. Uniform Construction Code 2009. However, they still have their own rules as far as how they supply fuel to a location and this is not widely published since only they are required to abide by it.

    I'd check your state building codes, local ordinances, State Fire Marshal's Office, utilities, and possibly some other boards and agencies. For instance, you can be held accountable to air quality districts, energy conservation agencies, OSHA, EPA, DOE, etc.

    Regardless of the source, always ask for a hard copy in writing. Then ask them for the rationale. In this case, it is often a matter of leak detection. If you have NG piped in you would expect a leak to rise up through the building while LPG would be hugging the floor. A search of a 'gas' leak might miss the LP at the floor or vice versa.
  • icesailor
    icesailor Member Posts: 7,265
    LP & NG in same building:

    I think that Tim is correct (as usual on things of gas). I just read something about it when looking for something yesterday in my Massachusetts PHCC CEU books.

    I think you may need special permission from the Board if you want to do it, and it must be specially marked, like 5# gas and with special marking consideration for both gasses to be separated. Like marking on both sides of walls, and specified spacing of markers in the pipe. Anything to stop an inadvertent connecting of the wrong gas to an appliance. Where I work, there is no Nat. Gas, only LPG. Most appliances come set up for Nat. Gas and need to be converted. Some lucky homeowner goes to Sears and buys a new stove and installs it without reading the instructions. The first time they fire it up, they get an adrenaline rush seeing a 1' yellow flame off a top burner. Gas dryers are even worse. The roar of the flame is considered normal.

    Common sense should prevail. How would you know that there was LPG in a building with a gas meter on the side, regulating Nat.Gas AND you have a buried LPG tank with a regulator and meter too? The possibilities of a screw up gives me a headache 
  • kcopp
    kcopp Member Posts: 4,261
    Just wondering....

    It just struck me that I had never heard of this before and wanted to know the chapter and verse so if I ever ran across it I would have the knowledge to know why or why not it was ok or not. I understand why it could be as issue.

    oddly enough I am looking at a job where they are looking to go Nat gas for 1 boiler and have 2 vent free heaters in the home (ugh!) that are lp now. They are looking to switch 1 boiler over to Nat gas and leave the other one as oil.
  • kcopp
    kcopp Member Posts: 4,261
    so is there....

    a true hard written code/ law or is it a good rule of thumb/ customary practice thing?

  • icesailor
    icesailor Member Posts: 7,265

    Without having my code book in my lap,

    It's allowable. You must get special permission and there are things you must do to be compliant. To be approved and compliant may be too big a PITA to make it worthwhile.
  • Bob Harper
    Bob Harper Member Posts: 986
    Taxachoosetts regs.

    The Commonwealth of Taxachoosetts is very strict and controlled by the unbelieveably powerful plumber's Board. Whatever they want they seem to get. Many appliance manuals now contain language describing the special conditions for approval in Mass. to install that appliance. Before, we used to spend $$$ on ridiculous amts. of paperwork including the entire UL listing report before you could install a single appliance! Insanity if you ask me...

    An example of mixed gases is where you have NG piped in for most of the building but they added on a gas fireplace, BBQ or fire pit at the other end of the house to where it was cheaper to set an LP cylinder with short skinny piping runs rather than upsize the existing main, meter, branches, etc. or go to either a 12.2 wci or 2 psi supply. Yeah, those fireplaces look REAL good when running LP through NG orifices!

    Be advised that in certain communities, there may be LPG piped in through meters fooling people into thinking it was NG. I battled with one local LP supplier who built their own aeration device thinking the aerated LP they piped into ~23 homes in one community would burn "just like natural gas". They went into each home and adjusted orifices, air shutters, manifold pressures, etc. but failed to notify any of the vendors. When some fireplaces totally gunked up with soot, I was sent out by the mfr. to investigate. After much wrangling I finally got a copy of their lab test showing a Sp.Gr. of 1.23 yet still tried to tell me it burned "just like NG". Those units were overfired about 80%. Constituted a fire hazard. Made them pay to replace all the guts including burners, to LP then they piped in straight HD5 LPG for 3 years until the NG pipeline reached them then paid again to convert to NG. Included clocking meters, leak tests-the works. Morale of the story is you cannot ASSume that a meter is providing NG. With LNG supplied in some areas, it can get even more fun. Try getting the Wobbe Index for that fuel. Note that most gas appliances sold in the US are tested and listed with regular NG or regular LPG and not blends. A few may also be tested for butane for certain communities where it is widely available and cheap but those are limited cases.

  • icesailor
    icesailor Member Posts: 7,265
    LPGand Nat. Gas in same building in MA:

    If you need, I'll post chapter and verse about mixing gasses in the same building. It can only be done with special permission. If given, the requirements are many. Nat pipe must be yellow, LPG must be green. It must be marked with stickers on the pipe at every wall or ceiling penetration. Among other things. Any building that has gas meters for both Nat, Gas and LPG in the same building is asking or looking for a very large problem.
  • kcopp
    kcopp Member Posts: 4,261
    thanks Ice...

    if  it comes to that then maybe I will take you up on that...kpc
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