# Uponer flow demand question



## Shoot'N'Plumber (Apr 27, 2013)

Hello PZ'ers, so I'm bidding on repiping a commercial facility and I will be using uponor, I would prefer copper,however, the well water is ridiculously high in manganese and other minerals that has been eating away at their copper. Right now there are 2 bathrooms each with 2 lav sinks, a 4.5 gal flushometer toilet and shower, then the rest is a standard kitchen sink and laundry with utility sink. The building is fed with 2" copper main. My initial plan was to isolate each restroom on separate feeds of 1-1/4", and run separate lines from manifold for kitchen and laundry, however, will 1" uponor meet the demand of each restroom. I know how to size and what my demand chart tells me, I'm just concerned that the reduction in I.D at the fittings will affect my flow to the flushometer. Any thoughts from more seasoned uponor users. Thanks


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## TX MECH PLUMBER (May 27, 2011)

No 1" isn't large enough. I've seen it. Had three 1.6 fv on a 1" line the middle one worked fine. The ones on the end of the line didnt and I had to put in 4.5 diaphragms in them. 
Def run 1 1/4" all the way to the fvs. At least to the drops


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## Shoot'N'Plumber (Apr 27, 2013)

Hi there TexMech! Thanks for the reply, my idea was to run separate supply mains to isolate each restroom so I would have 2 isolation valves off a brass manifold with shut offs in water heater room, so my demand on each SEPARATE trunk line will only be 2 lavs, 1 toilet and 1 shower so only 1 toilet on either a 1" or 1-1/4". So still stick with 1-1/4?


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## plbgbiz (Aug 27, 2010)

The extra 1/4" is much cheaper than explaining the lack of volume after your done.


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## wyrickmech (Mar 16, 2013)

plbgbiz said:


> The extra 1/4" is much cheaper than explaining the lack of volume after your done.


and a extra 1/2 would not hurt either


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## Shoot'N'Plumber (Apr 27, 2013)

Well right now both are being fed off of a 1-1/4" trunk reduced to 1" in the wall so I'm sure 1-1/4" separate trunk lines will be adequate. Thanks for the responses and input fellas!


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## plbgbiz (Aug 27, 2010)

Shoot'N'Plumber said:


> Well right now both are being fed off of a 1-1/4" trunk reduced to 1" in the wall so I'm sure 1-1/4" separate trunk lines will be adequate. Thanks for the responses and input fellas!


Don't shoot for "adequate". Aim higher and even if you miss, at least it will still be adequate.


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## TX MECH PLUMBER (May 27, 2011)

Shoot'N'Plumber said:


> Hi there TexMech! Thanks for the reply, my idea was to run separate supply mains to isolate each restroom so I would have 2 isolation valves off a brass manifold with shut offs in water heater room, so my demand on each SEPARATE trunk line will only be 2 lavs, 1 toilet and 1 shower so only 1 toilet on either a 1" or 1-1/4". So still stick with 1-1/4?


Water closet f.v. Needs 1" copper. And with out any thing els fed off the line. Ad a lav and u need 1 1/4. So on pex you'd need 1 1/4 just for the water closet and maybe larger. Matters friction loss for fittings and distance from manifold. It's all about fixture units but I'm not a master yet and don't know how to size pipe that way I just know from past jobs and what I was told FYI in the past when I'd have say 4 1.6gal w.c. On a wall. Instead of dropping down in size after every fixture like was drawn I'd just drop down once. Lot simpler install and more then enuf volume 

How far is ur run to the restrooms from the mech room ?


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## LIQUID (Sep 26, 2013)

plbgbiz said:


> The extra 1/4" is much cheaper than explaining the lack of volume after your done.



I'm with this guy. Like I tell apprentices.. aim for perfection and be happy when u get good enough. Always oversize ( within reason )


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## Shoot'N'Plumber (Apr 27, 2013)

TX MECH PLUMBER said:


> Water closet f.v. Needs 1" copper. And with out any thing els fed off the line. Ad a lav and u need 1 1/4. So on pex you'd need 1 1/4 just for the water closet and maybe larger. Matters friction loss for fittings and distance from manifold. It's all about fixture units but I'm not a master yet and don't know how to size pipe that way I just know from past jobs and what I was told FYI in the past when I'd have say 4 1.6gal w.c. On a wall. Instead of dropping down in size after every fixture like was drawn I'd just drop down once. Lot simpler install and more then enuf volume
> 
> How far is ur run to the restrooms from the mech room ?


From manifold to f.v. Is approximately 37' . I know over sizing is always good ,however, this bid needs to be spot on so the difference in going from 1-1/4" trunks to 1-1/2" is fairly slsubstantial as my manifold will be comprised of 1-1/2" brass, with reduced trunks as needed for four zones all on full port (lead free, ouch) ball valves along with required uponor x MIP adapters.


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## plbgbiz (Aug 27, 2010)

Shoot'N'Plumber said:


> From manifold to f.v. Is approximately 37' . I know over sizing is always good ,however, this bid needs to be spot on so the difference in going from 1-1/4" trunks to 1-1/2" is fairly slsubstantial as my manifold will be comprised of 1-1/2" brass, with reduced trunks as needed for four zones all on full port (lead free, ouch) ball valves along with required uponor x MIP adapters.


What percentage of the total job is the difference between 1-1/2 and 1-1/4 on two manifolds?


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## Shoot'N'Plumber (Apr 27, 2013)

Howdy PZ'ers, so just an update on the repipe project, I ended up going with a 1-1/4" trunk line from a manifold in water heater closet to the tee off above toilet where I reduced down to a 1" drop to flush valve, I then caught my shower and lavs after said 1-1/4x1-1/4"x1" tee. The toilets flushed just fine even while running the shower and lav, so a 3.5 GPF F.V will run fine off a 1/14" uponor trunk line


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## Plumbus (Aug 4, 2008)

Shoot'N'Plumber said:


> I'm bidding on repiping a commercial facility and I will be using uponor, I would prefer copper,however, the well water is ridiculously high in manganese and other minerals that has been eating away at their copper.


If the incoming *H*2*O* is that out of whack mineral wise, what do they drink in that building, bottled water?


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## Shoot'N'Plumber (Apr 27, 2013)

Plumbus said:


> If the incoming *H*2*O* is that out of whack mineral wise, what do they drink in that building, bottled water?


Well it's not necessarily the water that's bad other than the manganese and low ph, the problem is the extremely high copper concentration leaching into the water thereby making it unsafe to drink, and yes the fire crew drinks and cooks with bottled water, however after the repipe and water filtration it is now GTG. Trying to upload pics of the copper pipe and valves to show deterioration


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## Shoot'N'Plumber (Apr 27, 2013)

6 yr old 2" copper pipe, about half of diameter gone


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## Shoot'N'Plumber (Apr 27, 2013)

This is what the laundry sink


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