# Residential systems



## Paddy (Sep 2, 2011)

Sprinkler contractors use copper or CPVC pipe to install NFPA 13D systems. They now have another option that reduces labor and material cost. They can use PEX pipe on 3/4-inch looped layouts, and at least one manufacturer has it listed for exposed installation. This is a big benefit for installing 13D systems in basements with unfinished ceilings.

PEX systems have two advantages. The flexible pipe eliminates the tees and fittings needed to install rigid pipe. PEX sprinkler fittings come as a unit and eliminate the tees, drop pipe and adapters needed for rigid pipe. I prefer Uponor's system, and I know that their 3/4-inch pipe is listed for exposed installation.


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## GAN (Jul 10, 2012)

Not convinced on PEX yet. May turn out to be fine.

All the municipalities in my are have intentionally removed that section or left it as optional in the 2012 IRC.


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## Paddy (Sep 2, 2011)

I did that drawing! It is a layout for 1/2" PEX plumbing-based sprinkler system, where the same pipe supplies the sprinklers and cold water plumbing fixtures. Uponor did the installation in New Mexico.


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## 5onthefloor (Sep 13, 2017)

Paddy said:


> Sprinkler contractors use copper or CPVC pipe to install NFPA 13D systems. They now have another option that reduces labor and material cost. They can use PEX pipe on 3/4-inch looped layouts, and at least one manufacturer has it listed for exposed installation. This is a big benefit for installing 13D systems in basements with unfinished ceilings.
> 
> PEX systems have two advantages. The flexible pipe eliminates the tees and fittings needed to install rigid pipe. PEX sprinkler fittings come as a unit and eliminate the tees, drop pipe and adapters needed for rigid pipe. I prefer Uponor's system, and I know that their 3/4-inch pipe is listed for exposed installation.


Doesn't this type of pex loop also negate need for backflow protection since water is not sitting stagnant?

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## GAN (Jul 10, 2012)

Yes the full loop with no dead ends eliminates the requirement for backflow protection.

There is a potential for so much more piping to do this, you may well be better off with a closed system, stay away from chemicals and use a double check.


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## Paddy (Sep 2, 2011)

5onthefloor said:


> Doesn't this type of pex loop also negate need for backflow protection since water is not sitting stagnant?
> 
> Sent from my SM-G930V using Tapatalk


Yes.


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## Paddy (Sep 2, 2011)

A 3/4" simple loop will use the same amount or less pipe than CPVC or copper. It also eliminates all the Tees, elbows, drops and bracing that the rigid pipe systems require.


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## GAN (Jul 10, 2012)

Paddy said:


> A 3/4" simple loop will use the same amount or less pipe than CPVC or copper. It also eliminates all the Tees, elbows, drops and bracing that the rigid pipe systems require.


If you don't have a ceiling the pipe needs to be steel (basements).

Each head is required to be fed by three lines. NFPA 8.4.3.3


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## Eddy k (Jan 30, 2015)

Have you guys heard of what my first plumbing employer called Tri water. He made it sound like he designed this system. Say there was a multi story building, fire guys would run two mains on each floor with outlets for fan coils. We ran piping boiler to and cooling towers and was a fire sprinkler main. We did a lot of them. Saved on one extra 3 or 4" main down tight corridor. I am not much of a heating guy maybe there were other benefits I did not know about.


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## jnohs (Jan 27, 2012)

That is the dumbest system ever'


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## 5onthefloor (Sep 13, 2017)

jnohs said:


> That is the dumbest system ever'


Which the pex?

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## Paddy (Sep 2, 2011)

Not so sure. There is a way to combine fire sprinklers with domestic water in hi-rises, but it requires several things that domestic systems do not have. Examples are UL listed pumps that supply both systems, risers that comply with NFPA 13, etc.


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## GAN (Jul 10, 2012)

Ya the high rise is different.

The NFPA 13D is designed for SFR one and two family dwellings.

The NFPA 13R is for residential occupancies up to and including 4 stories.

More than that the full blown suppression systems which if not top fed are not good.


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## Dtmack87 (Dec 1, 2017)

Paddy said:


> Sprinkler contractors use copper or CPVC pipe to install NFPA 13D systems. They now have another option that reduces labor and material cost. They can use PEX pipe on 3/4-inch looped layouts, and at least one manufacturer has it listed for exposed installation. This is a big benefit for installing 13D systems in basements with unfinished ceilings.
> 
> PEX systems have two advantages. The flexible pipe eliminates the tees and fittings needed to install rigid pipe. PEX sprinkler fittings come as a unit and eliminate the tees, drop pipe and adapters needed for rigid pipe. I prefer Uponor's system, and I know that their 3/4-inch pipe is listed for exposed installation.



I know very little about fire suppression systems. Is there any concern about the potential flow/volume loss of the pex v/s the copper?

Again, excuse my ignorance on this system. The only thing we do with fire suppression is testing on the back flow prevention.


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## GAN (Jul 10, 2012)

Yes, restricted flow is a concern. One reason PEX multi-loop systems use interconnected 3/4".

The other thing a 13D system (one & two family) or 13R (up to 4 family) any residential is not designed the same as a commercial system. Residential systems are designed to slow the spread down and potentially out. Commercial systems are designed to put fire out generally.

http://www.nfpa.org/~/media/Files/forms%20and%20premiums/101%20handbook/101hbchs3.pdf


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## youthfulyellow (2 mo ago)

I did that drawing! It is a layout for 1/2" PEX plumbing-based sprinkler system, where the same pipe supplies the sprinklers and cold water plumbing fixtures. Uponor did the installation in New Mexico.


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## PlumberPhil (3 mo ago)

youthfulyellow said:


> I did that drawing! It is a layout for 1/2" PEX plumbing-based sprinkler system, where the same pipe supplies the sprinklers and cold water plumbing fixtures. Uponor did the installation in New Mexico.


Ooooh goodie! I've been waiting to be the one to do this...AHEM

Nice intro you got there😏


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