Plumbing planning.

I can’t begin to tell you how much I loathe plumbing projects.  That said, it needs to be done.  The area in which I live tends to have very acidic water.  The last 2 houses I owned had water that was acidic enough to require remediation.  The last house I had a soda ash system.  Soda ash systems require monthly maintenance, but are very inexpensive to maintain.  Calcium carbonate systems (which I currently have) require yearly maintenance and the media is generally more expensive, but really don’t require much thought day to day.  The pipes in my house are copper and have been exposed to acidic water for an unknown amount of time, so we’re not sure of the integrity of the pipes.  Coupled with the fact that my neighbor has had leaks caused by acidic water prompted me to make the decision to replace the plumbing while we had so many walls open.

I started with the following:

  1. Hot water took way too long to reach the point of use
  2. Water pressure was nothing to write home about
  3. Water sometimes has a coppery taste

This led me to:

  1. Hot water recirculation system
  2. New pressure switch
  3. Pex vs copper

One of the things about Pex is that it’s very easy to install home runs to each fixture.  It can also be installed as a trunk and branch.  Since I’m using a loop for the hot water and my plumbing fixtures are clustered, I decided to use a modified trunk and branch.

I began thinking in terms of where the plumbing fixtures were and I went around the house and started counting them and generated a spreadsheet:

Location Hot Cold Loop Group Fitting Size Fixture Units Comments
Downstairs:
Washer 1 1 4  1/2 4
Dryer (steam) 0 1 4  1/2 1
Dishwasher 1 1 0 4  1/2 1.5
Kitchen Sink 1 1 4  1/2 1.5
RO dispenser tap 0 0 n/a  3/8 0 Fed by RO
Dishwasher 2 1 0 4  1/2 1.5
Bar Sink 1 1 4  1/2 1.5
RO dispenser tap 0 0 n/a  3/8 0 Fed by RO
Reverse Osmosis System 0 1 4  1/2 1
Refrigerator water and ice 0 0 n/a  1/2 0 Fed by RO
Totals Group 4 5 5 12
Master Sink 1 1 1 1  1/2 1
Master Sink 2 1 1 1  1/2 1
Master Toilet 0 1 1  1/2 3
Master Shower 1 1 1  3/4 2 has its own manifold.
Master Bath 1 1 1  1/2 4
Hall Bath Sink 1 1 1  1/2 1
Hall Bath toilet 0 1 1  1/2 3
Totals Group 1 5 7 27 subtract 1 of each for master shower – 4 hot, 6 cold
Total Downstairs 10 12 39 subtract 1 of each for master shower – 9 hot, 11 cold
Upstairs:
Upstairs master sink 1 1 1 2  1/2 1
Upstairs master sink 2 1 1 2  1/2 1
Upstairs master tub/shower 1 1 2  1/2 4
Upstairs master toilet 0 1 2  1/2 3
Total Group 2 3 4 9
Upstairs Washer 1 1 3  1/2 4
Upstairs Dryer (steam) 0 1 3  1/2 1
Upstairs hall toilet 0 1 3  1/2 3
Upstairs hall sink 1 1 1 3  1/2 1
Upstairs hall sink 2 1 1 3  1/2 1
Upstairs tub/shower 1 1 3  1/2 4
Total Group 3 4 6 14
Totals – Upstairs 7 10 23
Totals – Upstairs + Downstairs 17 22 62
Outside:
Hosebib 1 1 5  3/4 2.5
Hosebib 2 1 5  3/4 2.5
Hosebib 3 1 5  3/4 2.5
Total Outside 3 7.5
Totals: Hot Cold
Group 1 – Master Bath 5 7 27
Group 2 – Upstairs Master 3 4 9 subtract 1 of 1/2 in hot and 1/2 in cold
Group 3 – Upstairs hall bath/laundry 4 6 14
Group 4 – Kitchen / Utility 5 5 12
Upstairs 7 10 23
Downstairs 10 12 39
Total Inside 17 22 62
Total Outside 0 3 7.5
Grand Total 17 25 69.5

With this, I knew how many and what size manifolds I needed to buy.  I got online and did a ton of research and ordered my plumbing supplies.  Again there are various pieces and parts that I can pick up locally but for the most part everything is ordered.

Oh, one last thing.  Fixture Units.  Rather than try to explain, here is the Wikipedia article.  Basically, at 70 fixture units, I need about 35 gallons/min, or in more rational units 132.5 l/min.

From this I generated a block diagram of the new plumbing.

Plumbing block diagram