Does this quote make sense? Dual Shower w/ Body Sprays

[zipsilver]

House has 1/2 supply lines.

Custom Shower Design
MOEN TS276BN
+
MOEN TS3400BN

Her Shower:
1 Moen Exactemp Shower Valves at 3/4" (2.5gpm at max) S3600
4 Moen Body Sprays new version at 1/2" piping (ea at 2.0gpm at max) Model TS1322
1 Moen Handshower

His Shower
1 Moen Exactemp Shower Valve at 3/4" (2.5 gpm at max)

Shower and Body sprays have independent volume controls.

Max demand her shower with everything on blast: showerhead and 4 valves = 10.5 gpm
Frequent use: Just dual showerheads at 5.0gpm


Contractor is finally willing to look at plans and says whoa big change order!
Plumber has not done any kind of pressure/flow tests, but contractor has decided to run seperate 3/4" cpvc in attic full length of house to bring 3/4 to shower. Does that make sense? Does this price make sense?
Others have said this Moen system works great with 1/2" and just stepped up to 3/4 for connections.
No Flow/Pressure tests have been completed.


NOTE: (plumber suggestion)
I have an additional 3/4" Cold water supply(Hose Spigot) right outside of bathroom wall.
20' from city meter.
(it may be 3/4, or it may be 3/4 spliced into 1/2' under ground he said)

[hj]

WE have no way of knowing because we do NOT know what your house looks like. But, since 1/2" CPVC is only slightly larger than 3/8" copper, I would question how much flow you would get from the valves if the length of the runs is substantial. Even those new 3/4" CPVC lines would only be the equivalent of 1/2" copper. In other words, 1/2" supply lines are ridiculous, and I would NEVER install them, assuming I would use any type of plastic piping.

[zipsilver]

I am not sure if you saw the details I took the time to include.
I did list the specific parts and rough in dimensions.
Here is an easier way to review the system and the solution they are proposing.
http://m.moen.com/search?search_term...UMER%3ATS276BN

and

http://m.moen.com/?s_kwcid=TC-15824-...MER%3ATS3400BN


There is no 1/2" except for the body sprays and they would be fed off the flow of the 3/4" run to the independent volume control.

The length fo the run is disclosed at 120'

The question is will running 3/4" CPVC (minus friction/fitting resistance negate any benefits of going up in size)
Would I be better off doing what the plumber suggested and just tying into an additional cold water near the bathroom for pressure?

[Terry]

The hot will need 3/4" from the water heater. The cold should also be a combined 3/4"
Most outside faucets are run with 1/2", even though the body of the faucet looks to be 3/4"
Plumbers normally run 3/4" cold to a bathroom set anyway to prevent shower shock if someone flushes a toilet while in the shower.
I wouldn't go to the trouble of putting that many shower heads in unless you can really supply them.
The Moen IOdigital system also has 3/4" incoming. There seems to be a pattern here. And like hj mentions, 3/4" CPVC isn't even that. For instance, you can't run plastic or PEX pipe to a tub spout diverter; it forces water out the shower head. Those are run in copper or full bore threaded pipe to prevent restriction. After the wall is tiled in, you options go down to nearly zip!

[jimbo]

Don't equate 3/4" CPVC with 3\4" copper or ips piping. Not close to the same thing,

[jadnashua]

When you say the house has 1/2" supply, is that from the street? If so, doesn't really matter what you do inside, the supply line is just too small.

[zipsilver]

Thanks Terry.

I did a lot of research on this forum and read that you have no seen problem with 2 Moen showerheads on 1/2" Copper.

I have already purchased both systems and rough-ins.




Question 1: Regarding the proposal above.
Will routing 3/4" (CPVC) at great expense provide any improvement over existing 1/2" Copper?

Question 2: What is a proposed alternate solution? (lines will be ran in Florida Attic approx 60')

Typical use: 1 Person = 2.5gpm plus body sprays
Main Showerhead and body sprays

Alternate use: 2 people
Just 2 shower heads will suffice = 5.0gpm

No Pressure Tests have been done even after requested.

Drain Requirements also:
Concrete is scheduled to be poured tomorrow around 2" drain.
I have brought up concern that I have read on here that this may not be adequate.

Water Heater: 50Gal Electric Dual element
House has 3/4" supply from Curb to Waterheater

Any advice is greatly appreciated.

[hj]

3/4" CPVC and 1/2" copper are almost the same size, and a plumber would SELDOM use it for more than two faucets, and even then on a short run.

[jadnashua]

About the most you can flow with 1/2" copper line is two showerheads. Now, if both you and your wife will be taking showers at the same time, and they share a 1/2" supply line, forgetaboutit.

You didn't answer my question...what is your supply from the street? What is it to/from the WH?

[zipsilver]

About the most you can flow with 1/2" copper line is two showerheads. Now, if both you and your wife will be taking showers at the same time, and they share a 1/2" supply line, forgetaboutit.

You didn't answer my question...what is your supply from the street? What is it to/from the WH?

3/4 copper from Street to Meter
3/4 copper from City Meter to WH

I spoke with the Contractor today regarding CPVC and he swears there is no difference between it and Copper regarding water supply to the shower.
Are there any officially recognized ratings that compare them? ANSI etc...

[nukeman]

CPVC and copper are both sized as CTS (Copper Tube Size) standard. This means that the outside diameter of either one is the same. However, the wall thickness in the CPVC pipe is much thicker, so the flow area is smaller. You can check the differences here:

http://www.engineeringtoolbox.com/ct...ns-d_1664.html

http://www.engineeringtoolbox.com/as...bes-d_779.html


The 3/4" CPVC is 0.713" inside diameter. A 3/4" copper (say Type L) is (0.875" - 2*0.045") = 0.785"

The difference doesn't sound like much, but if you figure the area, the increase is over 21% when going to copper.

I personally would use 3/4" copper in this situation. However, I also would install it myself, so the cost isn't much (just difference in material cost). I do know that if you ask for copper, the plumber will up the price since it will cost him more for materials and probably take more labor as well.

You want to be sure that you can supply the flow. You would hate to build the shower, install all those jets, and find that you can't use them because the flow just dribbles out.

[zipsilver]

Thanks nukeman!
I had checked out these specs.
I understand the smaller internal diameter is going to give faster flow, given the pressure as constant.
The faster flow will lead to greater resistance. I am not sure in this small residential application that will be significant.

The real nuts and bolts I need to know is given the same configuration from water heater to shower
6 foot vertical (up), Horizontal 60 foot, 6 foot vertical (down)
How big of an impact 3/4 CPVC will have on flow as compared to 3/4 Copper.
Should I be requesting the CPVC to be 1". (it appears this is a big jump in cost to this size.)

It is not so much the ID of the pipe I am concerned with. It is the internal fitting restrictions of CPVC.
Thanks again!

[lifespeed]

The faster flow will lead to greater resistance. I am not sure in this small residential application that will be significant.

The real nuts and bolts I need to know is given the same configuration from water heater to shower
6 foot vertical (up), Horizontal 60 foot, 6 foot vertical (down)
How big of an impact 3/4 CPVC will have on flow as compared to 3/4 Copper.
Should I be requesting the CPVC to be 1". (it appears this is a big jump in cost to this size.)

It is not so much the ID of the pipe I am concerned with. It is the internal fitting restrictions of CPVC.
Thanks again!

AFAIK, CPVC fittings have essentially the same internal diameter as the pipe they are mating, unlike PEX.

However, 60' is a long run and you most definitely will be subject to friction losses over distance. There are calculators for this.

As to cost, you are talking about plastic!! The difference in price between 1" and 3/4" plastic pipe can't be that much?

Check the frictional losses based on your total length, and add some more for elbows. If the drop in pressure is more than 5-10 psi either go to 1" plastic or 3/4" copper. Friction over a distance most certainly does matter. If you want a car wash shower put in the right pipes to feed it.

[toolaholic]

When the rubber hits the road 1/2' internal Diam, Ain't gonna do You!

[johnfrwhipple]

Aside from all the pipe sizes comments the actual cost of the new work does not seem out of line. If your on a roll with the change orders you can consider a few more options.

1). What about a heat recovery pipe on the shower's cold water intake? This can pre-warm the cold water reducing the demand on the hot while you shower.

2). What about a secondary hot water tank to pre-heat the cold water for the master shower. This I have not seen done but something I want to do in my own home.

3). A on demand hot water system for your en suite shower. Just in case you get all the flow you want and want to stay in the shower for more than 30 minutes.

Just more food for thought.

JW