# PEX



## conarb (Dec 2, 2009)

As most know California has approved PEX after years of debate, I've never seen it but I presume I'll be seeing it now.  A poster from Massachusetts posted this today:





			
				Lou said:
			
		

> A client had a pex fitting fail on a heating system full of glycol/water mix when no one was home and it ran for at least an hour. It ran down several stud bays as well as completely filled a floor/ceiling bay with water(stains on the carpet above and ceiling below). It was about 1 inch deep on the floor and soaked the bottom of all the walls causing some of the wall paneling to buckleWe are planing on replacing the sheet rock on the ceiling and the carpet . I know the water in the framing will dry out but what about the glycol ? it smells like a leaking radiator down there.
> 
> Does any one have any experience with this situation? can the smell be sealed in with kilz or similar product?
> 
> should we just plan on replacing all the walls in the basement or will drying out make it all better?


It was the fittings that created all the polybutylene pipe failures, is this stuff a time bomb waiting to happen?  Can you imagine the chances of failure with PEX in the slabs for heat, the walls for potable water, and the ceilings for fire sprinklers?


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## north star (Dec 2, 2009)

Re: PEX

*conarb,*

*As I understand the situation with pex, the fittings that were / are being installed on the*

*piping itself are the concern.   They will fail over time,  because of the continual expansion*

*and contraction of the piping.    The metal fittings will expand and contract for a while,*

*but then they lose their ability to contact enough to seal the piping.*

*Yeah, it's a problem that's going to get bigger.   :shock:*


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## Pcinspector1 (Dec 2, 2009)

Re: PEX

North star,

PEX information guide sez' the pipe can expand 1" in a 100' span, I have not heard of the fitting's being a concern. Do you mean the connection to the fitting is a concern?


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## jar546 (Dec 2, 2009)

Re: PEX

The fittings have always been the problem in any plastic pressurized piping


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## beach (Dec 2, 2009)

Re: PEX

We have about twenty buildings in one area that used it about eight years ago, no problems yet....waiting to see


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## north star (Dec 2, 2009)

Re: PEX

*Pcinspector1,*

*The rings that were / are being used to crimp onto the individual fittings are the problem.*

*Some pex installations are using a copper type ring in the crimping process.    I do not*

*know the actual composition of those rings,  but as I understand it,  those "copper type"*

*rings will expand and contract for a period of time.     Because of the continuous*

*stressing of the piping, as it expands and contracts,  the metal type rings will lose their*

*ability to contract back enough to maintain a seal on the fittings.       Some pex*

*installations have recommended using a metal fitting that will not expand and contract*

*as much, ...something like a stainless steel fitting, that will maintain its seal onto the*

*individual fittings and still allow the piping to expand and contract.*


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## Moscow (Dec 2, 2009)

Re: PEX

Here it been used for about 5 years no problems YET. the only thing that has happend is in a new apartment building and tenate left for x-mas break and shut all his heat off, the weather truned very cold and froze the whole apartment, it got so cold that the fish tank was frozen soild with the fish still in it. Anyways the only leak they had in the whold systme was a shut off valve under the sink pushed off the pipe and was spraying. If that would of been a copper system they would of had to repipe the whole apartment.

Justin


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## Uncle Bob (Dec 2, 2009)

Re: PEX

ConArb,

As you see; everyone states that there have been few or no reports of failure.

When a home owner has a water leak in the wall they don't call the city inspections department; and, the plumber does report the leak to the inspections department.

The homeowner calls a plumber who repairs the leak.

Cheap, unreliable products increase service calls.  It's a win, win situation for the plumbing companies.

There will never be any reliable reporting of plumbing pipe failures.

Uncle Bob


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## RJJ (Dec 3, 2009)

Re: PEX

I have a number of jobs with pex! Have only had a few problems with the fittings over the last ten years. Mostly at the time of new installation. Just a bad connection made! Have no reports of failure on projects up and running.


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## Mule (Dec 3, 2009)

Re: PEX

Same here. We've had PEX installed now for around six years and have not had any problems that I am aware of.


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## beach (Dec 3, 2009)

Re: PEX



> When a home owner has a water leak in the wall they don't call the city inspections department


If there were enough problems with Pex, you'd hear about it. It's been used for years in mobile homes, motor homes, campers and boats with no problems (or the manufacturer wouldn't use it for obvious reasons). Polybutylene was first used in mobile homes, etc., until a CLASS ACTION SUIT had the manufacturers switch to PEX...Hmmm, a class action suit....enough problems, and people COMPLAIN. I'm sure there were naysayers when plumbers started using copper instead of galvanized pipe....OMG, SOLDERED joints instead of threads and pipe dope??????? What kind of CRAP is that?? LEAD in my water????? We'll all die!! No problem, they switched to "lead less" solder, then it was ..OMG, LEADLESS SOLDER?? That will be too hard to sweat, the joints will leak.....



> Today’s plumbing in manufactured homes can be described as ‘on the cutting-edge of technology.’ Because codes for site-built houses are strict and hard to change, mobile-home manufacturers are often the first to test new technology. Thanks to mobile home manufacturers, this country is now seeing a shift towards plastic waterlines -- more specifically, a shift to cross-linked polyethylene (pex).





> Working with plastic waterlines is very simple, easy and fast. So why would plumbers scoff at that? One reason is that in many areas, codes for site-built homes have changed very little over the years. This has given many plumbers a good reason for not wanting to learn anything new. In fact, those same plumbers probably despise the new technology; therefore, they refuse to work on mobile homes.


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## conarb (Dec 3, 2009)

Re: PEX

So the idea is to lower the quality of site built homes down to the level of mobile homes?  Those damn building codes always do get in the way of new and innovative products, we should fire all those pesky building inspectors, all we really need is a fire code anyway, firemen make perfectly good inspectors and they need something to do anyway. 





			
				Class Action said:
			
		

> *Class Action Lawsuit Filed Against Zurn Pex and Zurn Industries Relating to Failure of PEX Plumbing Systems in Homes*ST. PAUL, Minn., Aug. 10, 2007 (PRIME NEWSWIRE) -- Homeowners in Minnesota have filed a class action lawsuit in federal district court against the manufacturer of residential plumbing systems. The homeowners, Denise and Terry Cox from Detroit Lakes, Minnesota, started the nationwide class action against Zurn Pex, Inc. and Zurn Industries after brass plumbing fittings used in their home's PEX plumbing system failed shortly after completion of their new home. The failures caused water and other damage at the Cox home.
> 
> PEX plumbing systems involve flexible plastic plumbing tubes (as opposed to the more common copper plumbing systems) that are attached to brass fittings throughout the plumbing system. "PEX" is a generic term for cross linked polyethylene -- the material used to make the plastic piping. PEX plumbing systems are the newest generation of non-copper plumbing systems coming into favor after the plumbing industry stopped selling the failure-prone polybutylene pipe systems.
> 
> According to Cox's attorney, Shawn Raiter, the problems with Zurn's brass fittings can cause significant damage to homes. "Water damage from a total failure, or even a slow leak, can cause serious damage. A large percentage of the brass fittings in a typical residential PEX system are hidden behind drywall or between floors. If undetected, water damage from a leaking fitting can even lead to mold, which in turn can pose a health risk.¹


¹ http://newsblaze.com/story/200708101350 ... story.html


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## beach (Dec 3, 2009)

Re: PEX

Zurn manufactured bad fittings, that doesn't mean the Pex is bad. That's like saying all copper plumbing is bad because Elkhart manufactured a batch of bad ninety degree fittings and flooded some houses. I get that you don't like plastic anything, or manufactured lumber products, etc. but the fact is...most homes will be built using that stuff long after you are gone from this earth. You can't live in the good 'ol days forever, you need to evolve. We've had some homes here that were less than three years old that had "bad copper" I didn't see it, but I think the plumber didn't ream the copper and the turbulance wore through the pipe or fittings, just my guess......but I did hear about it. My point is that UB stated that we will never hear about problems with pex if there are any..and I disagree.


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## RJJ (Dec 3, 2009)

Re: PEX

CA: I don't like pex but do allow it. Anything can fail! The statement that when a problem occurs they don't call the city inspector! That maybe! In my ahj they call me on just about anything even when they did something with out a permit or inspection and the job has problems. That is real dumb, but it happens.

When I was on the other side of the counter one job was a real mess. People had a new bath and kitchen installed. About six month after the install the supply line in the bath toilet popped. It was a brass line. New! The homeowners had left for work early and returned late. The house from the second floor to the basement was destroyed. What a mess. It wasn't pex! It was all copper and chrome. Anything can't fail. This is just one project. Never made it to city hall and probable was buried in some insurance static for water damage in a home.

Fact is pex is somewhat new! We may see problems! I would say that is to be expected!


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## conarb (Dec 3, 2009)

Re: PEX

The polybutylene failures that resulted in it's approval being withdrawn had to do with fittings too, so what's the difference between fittings failing on polybutylene and PEX? I think Uncle Bob's comments ran to the fact that this is the tip of the iceberg, maybe for every hundred or thousand PEX failing only one failure is reported? 

As to my hating low quality materials you should see what's happening with California's new voluntary Green Building Standards, people are already getting so sick in new homes that some can't even be occupied, at least one city is paying for air quality tests prior to people moving in. 





			
				Examiner said:
			
		

> New homes in Los Altos tend to have elevated formaldehyde. Exposure to formaldehyde causes asthma, bronchitis, sinus infections, headaches, and sleep disorders.Late 2007, the City of Los Altos passed an ordinance requiring new homes to be GreenPoint Rated. A program designed to conserve energy and resources, GreenPoint Rated homes are often designed with inadequate ventilation.
> 
> A large study funded by the State found that homes need about 1 air change per hour (ACH) to dilute formaldehyde to safe levels. Many GreenPoint Rated homes have less than 0.2 ACH. New regulations taking effect in January 2010 will only require 0.3 ACH.
> 
> ...


 ¹ http://www.examiner.com/x-5101-San-Jose ... -Los-Altos


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## beach (Dec 3, 2009)

Re: PEX

Pb fittings AND *pipe* broke down from chlorinated water. I stand by my example in my last post regarding copper fittings.

http://www.repipenews.com/


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## conarb (Dec 3, 2009)

Re: PEX

20 Years and $10 million dollars later it was banned, will the same thing happen to PEX?  We do have chlorinated water, that will never go away.


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## beach (Dec 3, 2009)

Re: PEX

You don't know if chlorinated water deteriorates Pex. I'm not going to play this game with you, it's been done before. Back up your claims before posting and stop the heresay.


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## conarb (Dec 4, 2009)

Re: PEX



			
				Beach said:
			
		

> You don't know if chlorinated water deteriorates Pex


No I don't, it's always been illegal here, I have seen it in Oregon and in a double-wide trailer that a friend owns up in Santa Rosa, all I know is  that in both cases the water pressure is very low, too low for me to enjoy a shower, in Oregon I was told that the low pressure is the PEX, that nobody knows how to install it properly and they clamp it too strong at the connections redistricting the tube diameter.

So tell us, does chlorinated water destroy PEX and/or its connectors?


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## Jasper (Dec 4, 2009)

Re: PEX



			
				conarb said:
			
		

> Beach said:
> 
> 
> 
> > You don't know if chlorinated water deteriorates Pex


So tell us, does chlorinated water destroy PEX and/or its connectors?

At least one manufacturer of PEX lines says that chlorinated water and ultra-violet light damage PEX:

http://www.calpipes.org/pdf/Lubrizol_Letter.pdf

According to Lubrizol, the best measure [available to most buyers] of the PEX lines' ability to resist such degradation is the length of the manufacturer's warranty against exposure to sunlight.  The best way to take advantage of such a warranty is to keep the lines out of sunlight, and keep the protection for use against the chlorine.


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## conarb (Dec 4, 2009)

Re: PEX

Thanks Jasper, it looks like California AHJ's should exclude the product if their water is Chlorinated. If it isn't chlorinated (which all municipal water in California is), then the AHJs should disallow it in recirculating hot water systems, Inspectors then have to make a field determination as to whether it's been exposed to UV light prior to installation.


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## RJJ (Dec 4, 2009)

Re: PEX

CA: The chlorinated issue is interesting! I would need more facts. However, No inspector has the time or the ability to make a determination if, or if not, that the Pex has been exposed to sunlight! Is 1 minute to much or is the right determination 3 days! Who Knows? Now I know you can find the facts. Next it is code approved! Big hurtle to overcome to deny such a product from use.


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## Jasper (Dec 5, 2009)

Re: PEX



			
				RJJ said:
			
		

> CA: The chlorinated issue is interesting! I would need more facts. However, No inspector has the time or the ability to make a determination if, or if not, that the Pex has been exposed to sunlight! Is 1 minute to much or is the right determination 3 days! Who Knows? Now I know you can find the facts. Next it is code approved! Big hurtle to overcome to deny such a product from use.


My hypothesis is that PEX uses up its rated life (against chlorine, other oxidants, and UV) in proportion to its exposure, with each exposure adjusted for time-at-temperature and concentration of the harmful influence.  Based on the information in Lubrizol's letter, I have a few SWAGs (scientific wild-ass guesses):

1)  If PEX with a 15 day warranty against exposure to sunlight is exposed to sunlight for 3 days, it has used up 20 percent of its rated margin for exposure to oxidants.

2)  If PEX with a 180 day warranty against exposure to sunlight is exposed to sunlight for 3 days, it has used up just two percent of its rated margin for exposure to oxidants.

3)  If PEX with a 15 day warranty against exposure to sunlight is designed to handle 50 years of exposure to chlorinated drinking water, then each day of exposure to sunlight potentially reduces PEX's life by a few years.

4)  PEX with a 180 day warranty against exposure to sunlight is designed to last a lot longer than PEX with a 15 day warranty against exposure to sunlight.


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## Jasper (Dec 5, 2009)

Re: PEX



			
				RJJ said:
			
		

> CA: The chlorinated issue is interesting! I would need more facts. However, No inspector has the time or the ability to make a determination if, or if not, that the Pex has been exposed to sunlight! Is 1 minute to much or is the right determination 3 days! Who Knows? Now I know you can find the facts. Next it is code approved! Big hurtle to overcome to deny such a product from use.


I am not a lawyer, but I would guess that for purposes of the code, you would need to look at three factors:

1)  Were the manufacturer's instructions followed?

2)  Was the product exposed to sunlight for longer than the manufacturer's warranty period against exposure to sunlight?

3)  Does your code have any special provisions?


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## Jasper (Dec 5, 2009)

Re: PEX



			
				conarb said:
			
		

> Thanks Jasper, it looks like California AHJ's should exclude the product if their water is Chlorinated. If it isn't chlorinated (which all municipal water in California is), then the AHJs should disallow it in recirculating hot water systems, Inspectors then have to make a field determination as to whether it's been exposed to UV light prior to installation.


There is a difference between what Authorities Having Jurisdiction should do, and what the law allows.  Now that the State of California has approved PEX, California AHJs have fewer options.  Unfortunately, I am under the impression that California's approval did not discriminate between types of PEX, nor did it consider the length of the manufacturer's warranty against exposure to sunlight.

Different kinds of PEX tubing have different properties.  For example:

1)  Silane PEX (PEX-B) can have far more anti-oxidants than PEX-A and PEX-C.

2)  PEX tubing can be lined to reduce the amount of oxygen that diffuses into the tube from the surrounding air.

Also, it is possible to change the amount of chlorine in a recirculating hot water system.


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## RJJ (Dec 6, 2009)

Re: PEX

Jasper: Interesting! is this a guess? where the info come from?


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## Jasper (Dec 6, 2009)

Re: PEX



			
				RJJ said:
			
		

> Jasper: Interesting! is this a guess? where the info come from?


Yes, most of my conclusions are guesses, based on:

 * The information in Lubrizol's letter

 * Other websites I looked at when I wanted to improve wikipedia's article on PEX.  I put some notes at:  http://en.wikipedia.org/wiki/Talk:Cross-linked_polyethylene#Comparison_of_types

 * Basic "chemical kinetics".  "Chemical kinetics" is the theory of how fast a chemical reaction uses up its reactant(s) to produce its product(s).

Each chemical reaction has a different rate.  Most chemical reactions have the following properties:

 * The rate depends on the chemicals involved, and what intermediate products are created along the way.

 * The rate increases (roughly exponentially) with temperature.  A 10 Celsius degree increase in temperature can double or triple the reaction rate.

 * The rate increases (possibly non-linearly) with the concentration of each reactant.

 * The rate depends on whether there is a catalyst.

 * The rate depends on the solvent.  In this case, the reaction happens in the tube material.

The degradation of PEX has the following reactants:

 * Something that causes the damage, such as chlorine or ultra-violet light.

 * The cross-linked polyethylene.  (This has a fairly constant concentration, because it is most of the material.)  Different kinds of PEX have different kinds of cross-links, so some kinds might be slower to be damaged.

 * The anti-oxidants in the material.  I assume the anti-oxidants are used up as they "try" to repair the damage.  I assume that the tube will fail when it no longer has enough anti-oxidant in a spot to prevent a leak.  Different kinds of PEX start out with very different amounts of anti-oxidants.

Basically, I am assuming that the amount of anti-oxidants used up is the sum of:

 * The number of days exposure to sunlight * the amount of UV in the sunlight * a fudge factor, adjusted for the length of each day and the temperature of the PEX and whether the PEX contains any "sunblock".  Many black plastic pipes use graphite as a "sunblock".

 * The number of years exposure to chlorinated water * the concentration of the chlorine in the water * another fudge factor, adjusted for the temperature of the water and whether any linings prevent the chlorine from diffusing into the PEX.

I am also assuming that each PEX tube has a potential life, if it were never exposed to chlorine or UV.  In effect, I assume that exposure to sunlight uses up some of the tube's life, and exposure to chlorinated water uses up more of the tube's life.  Of course, you can only find out how long any particular tube will last when it fails.  I hope that PEX tubes that are warranted against 180 days of exposure to sunlight have long potential lives (if they are kept out of sunlight).

A similar theory is used to estimate lung-cancer risk -- a smoker's risk of dying of lung cancer is roughly proportional to the number of cigarettes they have smoked, times the average time they kept the smoke inhaled.  In the lung cancer analysis, body temperature is fairly constant, so it does not factor into the results.  And yes, I knew a woman who never smoked who died of lung cancer.


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## Jasper (Dec 6, 2009)

Re: PEX



			
				Jasper said:
			
		

> And yes, I knew a woman who never smoked who died of lung cancer.


This just goes to show that there is a difference between theory and practice.

Thus, code inspectors are wise to ask for tests to show how long products are likely to last.  Unfortunately, I do not know of any test that can prove that a product invented in the last 100 years will last as long as I want my house to last.

On the other hand, PEX is not the only plumbing product "invented in the last 100 years", and it is not the only product that can fail if exposed to "harsh" conditions.  The best kinds of copper (for various applications) were also "invented in the last 100 years".  Copper pipes, galvanized steel pipes, and other kinds of plastic pipes also have known failure modes.


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## conarb (Dec 6, 2009)

Re: PEX

Jasper:

The Cal Pipes article says:





> PolybutyIene (PB) is still being used in a many parts of the world for hot and cold potable water applications because those parts of the world don't rely on chlorine for the purification of their water. Countries that don't chlorinate their potable water use ozone, reverse osmosis, carbon or ground well systems. There is a direct scientific connection between chlorinated water and Polyolefin based materials decreased performance and longevity


Since the claim is made that PEX has been proven by many years of use in Europe, do you know if the European countries chlorinate their water?


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## Jasper (Dec 6, 2009)

Re: PEX



			
				conarb said:
			
		

> Since the claim is made that PEX has been proven by many years of use in Europe, do you know if the European countries chlorinate their water?


I am afraid I do not know much about water chlorination.  For purposes of analyzing customers' pipe durability, the concentration of chlorine compounds "at the tap" is more important than whether the water is chlorinated at all.


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## Jasper (Dec 6, 2009)

Re: PEX



			
				Jasper said:
			
		

> For purposes of analyzing customers' pipe durability, the concentration of chlorine compounds "at the tap" is more important than whether the water is chlorinated at all.


A quick Googling shows that there are two common measures of chlorine concentrations:

* "Free chlorine" (HOCl/OCl-) in acidic water damages copper pipes, according to http://www.springerlink.com/content/kh872002rt2547p8/

* "Total chlorine", especially in acidic water, kills fish and other aquatic life, according to http://www.h2ou.com/h2wtrqual.htm#Chlorine

I do not know which measure is better for estimating the life of a PEX tubing system.


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## Jasper (Dec 6, 2009)

Re: PEX

Animal Lab News (ALN) Magazine has an article on what the "free chlorine" measurement means.  As pH increases, the "free chlorine" changes from Cl2 to HOCl to OCl-.  The article is "Animal Drinking Water Chlorination and Monitoring", by Susan McDaniel and Stacey Smart, in the September 2008 issue:  http://www.alnmag.com/Article_Print.asp?pid=367

The article further explains that:



> Combined chlorine is defined as the amount of chlorine existing in water in chemical combination with ammonia or organic amines. The disinfection capability of combined chlorine is much more limited than free chlorine. Ammonia is sometimes deliberately added to chlorinated public water supplies however, as combined chlorine is more stable than free chlorine and provides a residual chlorine concentration for a longer period of time. Total chlorine is simply the sum of free and combined chlorine.  Free chlorine is the strongest disinfectant of the chlorine family, and the measure of its concentration is the number that is of concern when determining the chlorine residual in water.


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## conarb (Dec 6, 2009)

Re: PEX

Jasper:

I don't really understand this, they say that France doesn't chlorinate then the chart seems to show that they do, apparently the European countries use a combination of Chlorine, Ozone, UV and reverse osmosis, while we us strictly chlorine?

I stumbled upon something else that I wonder about in researching this.





			
				Wikipedia said:
			
		

> Household reverse osmosis units use a lot of water because they have low back pressure. As a result, they recover only 5 to 15 percent of the water entering the system. The remainder is discharged as waste water.¹


I installed a fancy reverse osmosis system under the kitchen sink when my mother was alive, we never use it now, but I have a $300 a month water bill which I've always attributed to watering landscaping and too many showers.  Now I wonder if that thing is sitting there wasting water all day long?  Do they use water when not used? If so I better turn it off.

¹ http://en.wikipedia.org/wiki/Reverse_osmosis


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## Jasper (Dec 7, 2009)

Re: PEX



			
				conarb said:
			
		

> Wikipedia said:
> 
> 
> 
> > Household reverse osmosis units use a lot of water because they have low back pressure. As a result, they recover only 5 to 15 percent of the water entering the system. The remainder is discharged as waste water.¹


I installed a fancy reverse osmosis system under the kitchen sink when my mother was alive, we never use it now, but I have a $300 a month water bill which I've always attributed to watering landscaping and too many showers.  Now I wonder if that thing is sitting there wasting water all day long?  Do they use water when not used? If so I better turn it off.

If the schematic you linked to is accurate, it probably does use a lot of water all the time.  It does not seem to require any electrical power, so it probably does not have any electronics, and it probably is powered by water pressure.  Reverse osmosis is similar to pumping water uphill.  Using water pressure to pump part of the water uphill results in a lot of "waste" water.  If it does not have any electronics, and if it does not have any feedback loops from the output tank, then it might not shut off when the output tank is full.  At 45 gallons per day (of output), this system is slower than typical 2 gallon per minute tap usage, so it probably runs continuously to try to feed the output tank.

If you "never use it now," turning it off seems like a very good idea.  Please let us know whether you notice the difference in your water bill.


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## JBI (Dec 7, 2009)

Re: PEX

My pappy never had these problems when he was a young-un. Just went to the well, bucket in hand, and came back with water. No Chlorine, flourine or BS. Just plain old water. Ah, the good old days!


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