Multiple Shower Heads

[JohnF]

I'd like to install 3 or 4 shower heads in a 2nd floor bath remodel. It would also have a tub. The hot and cold water supply lines are 3/4 copper and the run is approximately 35 feet to the shower on the second floor. The supply lines originate in a basement. Can you tell me what I must do/buy/install to have adequate water pressure/volume. Should each shower head have its own shower valve. If I reduced the number of shower heads to

2 would anything special be required. TIA John

[SofaKing]

This sounds do-able but it may depend on your water pressure as so how satified you are with the results. Personally when making anything from scratch like this myself I'd build a mock-up of the pipes and heads on a piece of plywood and connect it to the water system and see how it works. Most modern shower heads output 2.5 gallons/minute, ask yourself do you really want/need a shower that sucks 10 gals/m?. I'm not sure what effect the 35' rise in elevation would have either. Are you trying to simulate some of the modern shower which spray along the whole length of your body?

[JohnF]

Thanks for response. Want to have spray coming from different directions. The total run from hot water tank is approx. 35 feet. The rise from basement to shower head would be only approx. 15 feet. The 2.5 gpm is not to my liking. I use more water with these reduced flow heads than with older style. I'm trying to avoid the need and the cost to turn on 3 or four separate valves. I had read somewhere about a thermostatic mixing valve with no volume control but can't recall where or how it fits in. John

[SofaKing]

35' is also a long run. I have a run like this to the MB in my house. You'll be running the water a good minute or two before you see any hot. Make sure you insulate the pipes if possible. Another thing to consider is another is what I'm considering is putting in a tankless water heater dedicated to the bathroom. They're a little more money but you'll save a little in warming up time water use and you'll have a more comfortable shower (and sink?) because you'll never wait for hot water. I believe the mixing valves are to ensure you don't get scalded. Once you've determined the amount of flow you need you may want to add the valve which is rated for that capacity. Maybe one of the plumbers on the rec can give you better advice.

[Ivan]

Are you looking for a full flow or just a relaxing full body misting? Have you considered a lower flow nozzle such as the ones a green house might use for misting their crops? Or perhaps a pressure washer nozzle. Probably a whole host of low flow nozzles that might be applicable.

[JohnF]

My goal is to have 4 standard shower heads working simultaneously when I open the hot and cold valves in the upstairs bathroom to be. I'm sure that simply connecting them all together through one valve will either not work at all or give me a drizzle of water.

[John Hines]

Go over to the

and and see what they have.

You need a shower temp valve, and a 5 way diverter, which switches between different shower head options. One setting allows for 2 devices to be on at the same time (shower head and body sprays usually).

There are lots, and lots, of options for designing your own bath spa.

[Ivan]

[JohnF]

Thanks. A quick initial look shows a multiple diverter at Moen's site but am wondering if the 3/4" supply lines by themselves would supply enough volume to have a good flow. Would changing the 3/4" h/cold riser lines to

1" copper offer any advantages?

[JohnF]

Was wondering about pump but am concerned somewhat about noise and leaking down the road.

[John Hines]

Is your supply any bigger than 3/4" ? If not, then no.

They (the faucet companies) have a hi-flow version of the thermostatic valve, that flows a higher than the standard model.

Current shower heads and sprays are limited in their volume of water they can spray, so the piping size is less of a factor. 3 gpm isn't a real high flow rate.

If your going to have more than what a single temp valve can provide, then you need to have multiple, like one at each end of the tub.

[Edwin Pawlowski]

Just check the GPM rating for the heads and look up the flow through a 3/4" tubing. My book is not with me so I can't help. Remember that two pipes will be feeding the system. The limiting factor is probably the valve, not the feed lines. My guess is that the two 3/4" risers will give you much more than you will ever need. Ed

[Chris Lewis]

According to Edwin Pawlowski :

Remember that the whole system is fed thru one pipe, so, unless the pipe up to the water heater is larger than 3/4", _two_ risers doesn't get you double the flow rate.

And, yes, the valves will probably be the limiting factor. Look for gatevalves or full aperature ball valves preferentially. Washer-type stop valves wreak havoc on high flow rates.

[I've had some experience with trying to coax high flow rates - trying to run 10 or more irrigation sprinkler heads off a 1/2HP well pump. I've succeeded. Barely... ;-)]

Probably best is to check the GPM ratings as mentioned, and target a total flow rate in the 4-5GPM range. 3/4" is capable of much more (like 13 or so), but this leaves you with higher pressure at the nozzles (giving a vigorous shower rather than something wimpy) than going flat out.

Jury-rigging the devices together is a good way to tell whether it's going to be satisfactory.

[Edwin Pawlowski]

Yes, I did not think it through completely. Most homes are fed with a 1" main so the maximum would be that, not matter how large the branch. FYI, my reference book shows 3/4" can handle 53 gpm at 10 psi and 119 gmp @ 50 psi. Feeding will not be the problem, the heads will be more restrictive than the lines. You can get a nice shower at 2 gpm and the right pattern, so four heads are easily fed.

[JohnF]

[Chris Lewis]

Some of my experiences show that even _if_ the main is 1", they're often crudded up badly. So, while you get reasonable operation up to a certain point, they perform really badly at moderate-to-high flow rates.

Are you sure about those numbers? Is that reference of yours a plumbing handbook or "physical properties" book?

It was my understanding that 1/2" pipe shouldn't be expected to deliver more than about 7-8GPM, and a 3/4" pipe 12-15GPM in normal residential situations.

Being a rule of thumb taking into account elbows etc.

Anything higher than those numbers implies that the water velocity down the pipe is causing pipe friction ("drag") to skyrocket. Resulting in impractical- for-residential pump power requirements.

[barry martin]

J > My goal is to have 4 standard shower heads working simultaneously when I J > open the hot and cold valves in the upstairs bathroom to be. I'm sure that J > simply connecting them all together through one valve will either not work J > at all or give me a drizzle of water.

My guess is would get a "heavy drizzle". The problem is supplying a sufficient amount of water to all four shower heads simultaneously. Remember the problem of being scalded by hot water when someone flushes the toilet? The water pipes can only supply so much water.

Solution would be to have larger water pipes BUT I would think this would mean all the way to the city supply under the street. If the shower heads use one gallon per minute each (no idea if this figure is accurate or not - let's use '1' as it's a simple number for the example) then four shower heads use 4 gal/min. The control valve needs to be able to pass at least 4 gal/min, and the hot and cold water pipes to and from the valve this volume also. (OK, two in's and one out!)

The cold water side isn't too much of a problem but the water heater may be. Not only does it have to be able to connect to the potentially larger diameter pipes (input and output) but also needs to supply 4 gal/min for a 10 minute or so period. ...Guess that's a 40 gallon capacity (4 gallons x 10 minutes).

Well, probably should have deleted this message but won't and endure a bit of scolding for being so stupid. Guess what: we'll both learn! Personally I'd test all this out -- think you or someone suggested than already. Buy some plastic pipe, connectors, glue, valve, the four shower heards, etc. Connect it up and run it for the length of a shower and see what happens. If it doesn't work you'll know for sure and maybe can use the test jig to water the flowers. :)

- ¯ barry.martinþATþthesafebbs.zeppole.com ®

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