Click here to Find a Contractor in your area.
In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
Need to contact us? Visit

Fire Sprinkler Protection

radmixradmix Member Posts: 189
 I'm installing a sprinkler system that the design calls for 160' 0f 11/4"  pipe over 10 hotel units. The problem is that the attic space is unconditioned. There will be 10 drops off of the main to the rooms below. Some of the units will be unoccupied in the winter months. The only thing I can come up with is to use Temp. sensitive heat tape then wrap in insulation. Does anyone have any other ideas.


  • icesailoricesailor Member Posts: 7,265
    edited March 2014
    Fire Sprinklers:

    Where I used to live, any system that met that criteria (potential freezing in unconditioned spaces) was a dry system, filled with compressed air and the drops were protected with specially manufactured drops that capped the end of the pipe so it wasn't filled with condensate or flood water. Only the head opening would allow the water into the drop pipe and into the head.

    Was this system designed by a Registered PE with a stamp on it?

    "160' of 1 14" pipe over 10 hotel units"

    What about the mains? You can't feed 10 rooms off a single 1 1/4" main pipe. Does the Fire Department or Department of Public Safety have to approve of the plans? Does the insurance carrier know that there will be unprotected fire pipes in an unconditioned space in a wet system? They might have higher premiums if they do. When and if the system goes down because of a break, the insurance on the building goes up because it is unprotected until it is corrected and put back in service. Not to mention the damage from flowing water if it breaks.

    Don't stick your neck out on this unless someone is taking full responsibility with it in writing that you are absolved of any responsibility if anything freezes and breaks.

    Even with dry systems, you still get moisture/water in the system from the air compressor and you need condensate low point drips that must be checked and maintained. Or else, it will freeze and break.

    Be careful. Don't get hurt.
  • Jamie HallJamie Hall Member Posts: 6,708
    A dry system

    properly set up and plumbed is much the best way to go.

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-McClain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • Mark EathertonMark Eatherton Member Posts: 5,584

    I've seen exterior deck brush fire mitigation systems that were filled with glycerin for freeze protection, Dry systems can work, but have seen issues with them before, but have never seen a glycerin system fail, but they DO get leaks at the threads, for sure.

    Check with your local fire marshall and see what his take is, because regardless of what we think about it here, their word is the final word.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • SteveSteve Member Posts: 486
    The trouble with

    Dry systems is the noisy compressors

    I have never seen one that did not Leak air someplace.

    Mark on another note, Do you know if glycerin Is it okay to use with CPVC.

    A lot of the systems in one to three family homes In this area Have been installed with

  • icesailoricesailor Member Posts: 7,265


    You think it is a PITA to work on a heating system filled with Anti-Freeze? Wait until you see what happens when you have to pull a head in a glycerin system , that has 18" risers to the 1 1/4" laterals above the ceiling and to the glycerin above the head all has to come into a 5 gallon bucket you are holding to catch it, while on a 6' (or more) step ladder, it's getting full, the helper is no where to be found, and when he finally comes, he doesn't have another bucket.

    Pucker time.

    Properly designed and installed air systems are a beautiful thing. When maintained, they are an even more thing of wonderous beauty. No fire sprinkler system is a "Install it and forget it" system. They require maintenance. When the insurance underwriter does their annual look and see, that tag on the water valve better have all the initials and dates correctly in a row, with different pens.

    Seen that, dealt with that.

    Now they are putting them in residential homes with PEX? I'm waiting with baited breath to see how well that works.

    Someone told me that Legionella doesn't grow in PEX piping.

    Is that so?
  • icesailoricesailor Member Posts: 7,265
    Noisey Compressors:

    Compressors may be noisy when they run but it is a good indication of a system leak.

    Screw pipe doesn't leak. Especially after they started using Teflon Pipe Tape. Now, all the bigger pipe is Schedule 10 pipe (I call it :Tissue Paper Pipe") with grooved joints. Want to find the leaks? Just send me around. My high pitch hearing is so sensitive that I can hear a mouse run up a concrete block wall.

    Get out the leak detector soap. Watch those Victualic couplings leak past the rubber gaskets. If a whole section of the pipe isn't rotted out on the bottom from standing water in the pipes. In 1963, when I was a union carpenter, I worked on a large wood framed municipal building. I watched these two gorilla's from Grinnell sprinkle the whole place with screw pipe, a air system. As of 6 months ago, they have never had a leaking pipe that needed to be replaced. I had another long time account that was completely sprinkled in 1958, all Screw Pipe. Never a problem. Until during each renovation after 1980, everything was done with grooved pipe. It leaks like a sieve. So bad that recently, the compressor ran so often that they finally had to do something about it. I told them where the leak was, under the ground between two buildings with grooved couplings. An expensive fix.

    The solution? Put in another compressor. Let two do what one should have been easily able to do. More moist air. The maintenance person goes around once a week during cold weather, draining condensate water from the low point drips. So the pipes don

    t freeze and break.

    Progress, not perfection.
  • Mark EathertonMark Eatherton Member Posts: 5,584
    From e how...

    Glycerine as an Antifreeze

    Glycerine, also known as glycerin or glycerol, is a naturally occurring sugar alcohol. Glycerine lowers the freezing point of water by inhibiting ice crystal growth. Its low toxicity makes it a common choice for weatherproofing residential and commercial fire sprinkler systems. The National Fire Protection Association (NFPA) sets standards for sprinkler systems and requires that any system expected to be exposed to freezing temperatures must be protected by an antifreeze solution. NFPA code 13 requires any sprinkler system connected to a public water source must use a glycerine antifreeze solution rather than ethylene glycol to reduce the risk of poisonous chemicals returning to the water supply. In fire suppression systems containing chlorinated polyvinyl chloride (CPVC) pipes glycerine must be used as an antifreeze as ethylene glycol can corrode the plastic pipes and fittings.

    Read more:
    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • hot rodhot rod Member Posts: 7,094
    PG for copper or steel

    propylene glycol is what we used in steel or copper systems. Nobel and others glycol blenders have PG blends for fire protection systems.

    The CPVC Blazemaster pipe required glycerine.

    The biggest problem we had with glycerin was pumping it when it was cold. It would only pump with a gear pump which was a very slow process. Even when it is warm it's a thick syrup fluid, compared to 50% glycol blends.

    Usually when you fill the system there is an air space trapped at every head so the glycerin doesn't always touch the only threaded connection in the CPVC system.

    Until a head leaks or discharges :)
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • SteveSteve Member Posts: 486
    Thanks guys

    Great information
  • Mark EathertonMark Eatherton Member Posts: 5,584
    Not true Chris...

    In fact, I think that it grows better because its a neutral medium and it allows oxygen into the process. I've heard that copper is fairly good at surpressing some bacteria, but it too makes bio-film-slime, which can hide and shelter the bacteria.

    Where did he get his information from?

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • radmixradmix Member Posts: 189
    Thank You

    For all of your responses
  • icesailoricesailor Member Posts: 7,265
    Backflow's and Legionella:

    Actually, the potable water systems are supposed to be heavily protected from cross contamination between the non flowing/stagnant water and the flowing Potable water.

    Most of my comments have generic attributes.

    I worry about the ease of installing a PVC home fire sprinkler system. Especially houses on wells with well yields of 10 GPM or less and how long the water will be flowing after the power goes out.

    We Massachusetts plumbers KNOW that the 9D backflow goes BEFORE the 1156F fill valve, not AFTER the fill valve. But when heaters started doing boilers, that's how we used to find them. I contend that it is why Watts and other manufacturers came out with the combo valves so you couldn't install then backwards.

    I can see the DIY homeowner plumbers saying what's this thing for? Leave it out.

    You've been at this long enough to know that if there is someone out there with the ability to screw something up, they will find a place to practice their craft.
  • icesailoricesailor Member Posts: 7,265
    What about:

    What about Polypropylene Glycol?
  • hot rodhot rod Member Posts: 7,094
    pre-blended only

    looks like some new regs since I last installed fire protection.

    According to this Nobel sheet, only factory blended fluids, and limited %
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
Sign In or Register to comment.


It looks like you're new here. If you want to get involved, click one of these buttons!