Systems we don't talk about enough

We spend a fair bit of energy talking about how to build walls and roofs and foundations, but not very much talking about plumbing and electrical systems.
And yes, we talk about how to manage greywater and aspects of solar, microhydro and wind generated electricity.

But we do not talk very much about how to get running water into our self-built homes, or the parts of the electrical system after the storage batteries and the inverter.

So, I am working on the designs for our house, the one we will build for ourselves from the land we will live on, and I am thinking about questions like "How do we get water pressure? What kind of pipe to use and where? i.e., pvc pipe is commonly used for drains, but is it ok to use on the source side in a potable water system, or is there something else that should be used on the potable side? Is theree something better on the drain side?

Drains, you need a certain amount of slope for them to work properly, but how much is that?

Where do you run the pipes when you are doing cob walls (or strawbale, or earthbag, or...)?

It seems to me that there are probably some principles out there that could be helpful in figuring out placement of things like sinks and showers and bathtubs to maximize efficiency of water management, both incoming and outgoing, but I do not have a working knowledge of what they might be.

Similar questions about electrical systems - the merits of using DC versus AC, what kind of wiring to use, what conduit, if any, and how to decide whether a given run can be loose wire or should be contained in conduit? Where does the wiring go in various forms of construction?

In balloon frame houses with drywall, there is all that space inside the walls to put your pipes and wires. Not so much in many of the natural building modes.

How much water pressure does it take to provide a nice shower, or a functioning kitchen sink? Ways of providing reliable hot water for that shower or kitchen sink?

I am sure there are questions I have not thought of.

Peter for anyone owning or building a home these questions will certainly come up. Lately I have been planning a number of future projects where these things come into mind, like planning An outdoor shower, rewiring and re plumbing existing houses for solar and grey water usage.Trying to make things simple and elegant is difficult when you are juggling ac and dc power circuits in the space, incoming and outgoing water, Energy production and storage. I have not read any books specifically about these topics in regards to building a permaculture system from the intricacies of the home and moving outward, I'll try to find some.

These are interesting and important questions. I've wondered the same about alternative types of walls.

As a plumber and electrician, I have seen what industry uses. Knowing that they will be upgrading and adding to systems,there is a lot if use of chases, cable troughs,or just oversized conduit. In houses I have thought concealing cable and pipe runs behind baseboards and chair rails could facilitate both initial and subsequent work.
As for PVC, I am rather ungreen for some one who hangs out on this forum, but PVC or CPVC should be avoided in water supplies.
A hot water line made of CPVC will become brittle over time as the plasticizing chemicals leach into the water. This is what I have observed.

ABS is a much more stable plastic, but if the big box stores around here only Menards carry it, and I have never used it as of yet. It does seem to cost a little more,in terms of money, but it seems like a cheaper alternative environmentally. That being said, I am awash in scrounged PVC, and I intend to use it. Many parts of a city water supply pass through plastics like PVC on the way to your faucet,so if you are eating and drinking conventional food and water,you ate ingesting the leachate from such plastics.
I am eating and drinking conventional food and water, so using on hand PVC to build a greenhouse makes sense for me.
But if you are building your own water supply, copper or PEX are better choices.

Yes, avoid all PVC and use a cellular core drain product like ABS and I like copper for all drinking lines and PEX for everything else, running it through a manablock so that every plumbing appliance has it's own valved circuit, like an electric panel. If you have cool water, you can use it to cool food.
I always use conduit and THHN stranded wire because the resistance of this wire is about 1/2 that of romex. I usually use ENT flex aka smurf tube. Here's a couple of pictures of our most recent endeavors.

You see how the kitchen has a wall built in front of the 17" thick 3 wythe brick wall that can hold all of the modernities and add insulation to the home. This is one way, the other is to embed the conduits and pipes in the mass and yet another is to run them in the floor or build a chase. For me this is best, because of the level of control and accessibility for future modifications.

We sort of, um, accidentally used PVC for our source water pipes. Well, the guys got some good looking pipe and laid it, and only later somebody pointed out that it's PVC, so I got alarmed and googled a lot about it. To my great relief, all the sources I found said that PVC is stable at cold temperatures and doesn't start leaching until a fairly warm temp, I forget what. In our site, the PVC runs cold cold spring water to the storage tanks, and from there onwards there isn't any PVC. Phew!

But if you're starting from scratch, save yourself the worry and use some other pipe than PVC for pretty much all purposes. It is seriously nasty stuff, and anything you invest in higher priced pipes will last for decades and add peace of mind, if you go for something other than PVC.

Bill I was worried that you had so much water on an out side wall, till you mentioned insulation!

Your system looks great, are you tagging circuits and "water circuit" as you go?

This is what formulas I have collected for use building an outdoor shower. I heard regular municipal water pressures range from 30-60 psi. So here they are.
First will calculate your static pressure, the second will tell you the flowrate out of tank, the third will play with flowrate, velocity, and pipe diameter.


Hydrostatic pressure in a liquid can determined using the following equation:

p = h ρ g (1)

where

p = pressure (N/m2, Pa, lbf/ft2, psf)

h = height of fluid column, or depth in the fluid at which the pressure is measured (m, in)

ρ = density of liquid (kg/m3, slugs/ft3)

g = the gravitational constant (9.81 m/s2, 32.17405 ft/s2)

Hydrostatic pressure in a water column (density 1000 kg/m3) - or depth - is indicated below:

hydrostatic pressure water kPa Pa bar psi meter feet

Example - Pressure acting in water at deep 1 m

The density of water at 4oC is 1000 kg/m3. The pressure acting in water at 1 m can be calculated as

p = h ρ g

= (1 m) (1000 kg/m3) (9.81 m/s2)

= 9810 Pa

Example - Pressure acting in water at deep 3 ft
The density of water at 32oF is 1.940 slugs/ft3. The pressure acting in water at 3 ft can be calculated as

p = h ρ g

= (3 ft) (1.940 slugs/ft3) (32.17405 ft/s2)

= 187.3 lbf/ft2 (psf)

= 1.3 lbf/in2 (psi)

(Examples taken from hyperphysics)
--------------------------------------------------------
The flowrate is Q and can be found with Q= Av, where A is the cross sectional area of the pipe and v is the water velocity.
A more practical way to measure flowrate is with Q= c/t where c is the carrying amount of the tank, and t is the time is takes for it to go from full to empty.

---------------
The other formula is

V= Q / ((3600)(pi)(d/2)^2)

Where

d : Pipe Inner Diameter (m)
Q : Water Flow Rate (m³/h)
v : Water Velocity (m/s)

I have not gotten exceptionally far in trying to apply all these to a shower system, but I will.

William Bronson wrote: Bill I was worried that you had so much water on an out side wall, till you mentioned insulation!

Your system looks great, are you tagging circuits and "water circuit" as you go?

Thanks William,

The masonry wall only has an R-value of 4 or 5, but the dynamics of a mass wall enables much better real world performance, so the pipes didn't freeze before the restoration, but I agree; why chance it? We are adding R-15 stone wool for a mass dynamic enhanced R-20 assembly.

Oh yeah, everything is labeled. This 5 bedroom, 3 1/2 bath, 2 kitchen and 2 laundry home has 21 plumbing circuits and 32 electrical circuits, way past the capability of my memory!

Bill the work looks very clean and organized, excellent job!

Thanks Zach.

Here is a photo of a 20" thick adobe wall with romex buried in a groove that looked to be hatcheted out. This is during the replaster job.

This way works, but if we want to change a wire out, we will be replastering the whole room.

@Bill Bradbury

Why all the curly queues in the copper line?

I take it that all the red lines are water circuits, using PEX?
Are the blue water lines also PEX?

I don't recall ever seeing a water patch panel like that, is it industrial grade water distribution panel or the new thing on the block?

This thread started to address the use of PEX tubing in water supply lines but then trailed off. I did not come across any other PEX discussions in other threads, but admit the search was not exhaustive. All of the current water lines in our old home are copper. I assume that using PEX would significantly reduce cost and increase ease of installation on some remedial pipe work to accommodate a new hot water system. But it's always been a bit disturbing to use some sort of synthetic for home water delivery, especially hot water. Any comments or opinions on the safety of PEX for this purpose? Thanks.

So far as we know, there has never been a documented case of somebody being harmed by the plasticizers that may be leached out of cross linked polyethylene (PEX).

And, so far as we know, there are a tiny tiny number of people who have been adversely affected by copper piping. Not from the copper, but from the solder. For a long time now, lead solder has been banned from residential plumbing. But, things can happen...

PEX will likely last longer if your water is acidic, or has a lot of dissolved minerals, which is most of the U.S.


There is no wrong answer here.

But one useful fact is this. Everything leaches something. But it's a very slow process, and the leachate gets less and less over time. So, to mitigate the risk (real, perceived, whatever), most of leaching happens when the water sits without moving for 8 hours. When you get up in the morning, let the tap run for one minute. Boom, you just flushed 99.9% of the leachate out and now you're good to go, whatever piping you choose.

Same thing when you get home from work. The water has been sitting there for 8 hours and has picked up whatever the pipe wants to give off. Another flush for one minute, and you're totally safe again, if you are concerned at all.

So, a reasonable option might be to flush before drinking/cooking with water for the first year after new piping is installed, and then never bother again.

Lead is different, and can leach for decades. If you have lead solder, you should flush the lines every time the water has sat in there for hours and hours.

A lot of this depends on the pH of the water, so your mileage may vary concerning whether or not you "need" to flush the lines.

Thanks, Troy, for this helpful response. With as old as the copper is in this house, the solder probably had lead in it so we have been dealing with some of that already in the drinking water. The well water here tests out pretty good, even with a bit higher arsenic than desired. My hope is to just use the PEX tubing to create new junctions for a wall-mounted tankless water heater, with or without a small tank heater placed in series. With the PEX and the new fittings, it should be easier that using copper to mix and match if I am improvising and testing configurations. Your comments plus information elsewhere on the internet give me some confidence that, used with some thoughtfulness, it should be okay. Will be checking the acidity soon.....pretty hard water for sure. Thanks again.

While lead is some bad stuff, most installations with lead solder never contribute any meaningful amount of lead to the water. Only certain combinations of water quality and lead exposure cause the big problems.

Even places that had solid lead supply lines from the street to the house rarely caused real toxicity problems. Even under those awful circumstances, flushing still works.

John Weiland wrote:This thread started to address the use of PEX tubing in water supply lines but then trailed off. I did not come across any other PEX discussions in other threads, but admit the search was not exhaustive. All of the current water lines in our old home are copper. I assume that using PEX would significantly reduce cost and increase ease of installation on some remedial pipe work to accommodate a new hot water system. But it's always been a bit disturbing to use some sort of synthetic for home water delivery, especially hot water. Any comments or opinions on the safety of PEX for this purpose? Thanks.

John, I'd stick with copper if you can afford it. I have not seen a comprehensive field study by credible third party showing PEX is safe, on the contrary there is a lot of data showing it is not you'll find on this thread: http://www.greenbuildingadvisor.com/community/forum/green-products-and-materials/37891/what-greenest-and-best-material-use-indoor-plumbi

Read my "Terry" and Richard Beyer's opening comments if you don't want to read the entire long thread. Martin Holaday called Richard and I and asked us to stop posting on his site since we kept showing supporting data as to why much of the foam and plastics he recommends as "green" are not safe nor good for the environment: http://www.greenbuildingadvisor.com/community/forum/green-products-and-materials/37891/what-greenest-and-best-material-use-indoor-plumbi

That led me to Permie.com once called "green builing" now due to these green sites promoting sponsors and not safe materials "natural building" ....

Also, be careful what your read on the internet. Question it unless supported & posted by credible data and fact. Your life could depend on it.

Copper with lead free solder is the gold standard.

Even the report that highlights the potential risk of chemicals leaching from cross linked polyethylene note that flushing for several months would reduce the leaching risk in a meaningful way.

Peter: There have been a number of new forums created lately. I'm wondering if the primary subjects of this post might be best served by having forums of their own. The DIY Electrical Forum. The DIY Plumbing Forum. Etc. Perhaps a request to that effect to the staff might serve the purpose of not having this sort of question be lost in the Natural Building forum, and be easier access to the next people. Just a thought.

Thanks for these additional comments. In keeping with these comments and my thinking here, I'll likely use a small amount of PEX for creating modular junctions that will allow rapid reconfiguration in part of the water system. The rest will be done in standard copper with lead-free solder. Great to have all of your input here.

Bump!

I'm always amazed by how thoughtful and thorough the discussions are on this site in all the details of green living.