Wallsters have sharp eyes and a keen nose for truth! (PAH)

Mike T., Swampeast MO

And a damned good and concerned one at that...

I understand all except a thermostatic AND pressure-balanced valve...

hot_rod

thanks to eagle eyed wallsters

I came home to find a number of e-mails with each containing a link to the article below - no, not a virus this time - just a heads up thing that clearly shows we're gaining recognition for what is a very serious and deadly issue.

Keep those cards & letters coming!

http://www.cnn.com/2003/HEALTH/conditions/09/15/legionnaires.ap/index.html

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Robert O'Connor_4

We heard it from

you first!!

Regards,
Robert

hot_rod

One sentence!

that appears in virtually every article I have read "Most people exposed to the bacteria never get sick" keep this from being and open and closed (pun intended) subject when related to combo hydronic applications.

If this disclaimer had some number to it 75%, 85% 99%?? What percentage range are thay talking about when they say most??

Without that sentence the issue, for me, becomes black and white. The potential is real and definable enough to imediatly seek a ban on combined systems. The aurguments at the RPA site, of late, have been powerful on the anti combined opinion, I must admit. Hope all the plumbers don't resign

hot rod

doug_10

Too bad...

the article didn't mention the use of a constant higher setting on the HWH and a mixing valve (or valves), instead of the "flush" - which is just a temporary fix...treat the problem not the symptom!

People will "plan" to do this flushing every so often...then reality sets in.

At least it is getting some national attention. Way to go PAH!

Take Care, PJO

bill clinton_3

Hot Rod:

The problem with a simple answer to your question is that there is "exposure", and then there is EXPOSURE. The legionnaire's bacillus is quite common: I'm sure you've drunk your quota over your lifetime. To get sick from it you have to inhale it and from what I can gather, inhaling one or two probably wouldn't get you very sick: your body's responses could handle it before they multiplied enough to be a serious threat.

The threat of EXPOSURE occurs when "amplification" takes place: Under favorable conditions (favorable from the point of view of the bacteria) a geometric increase in legionella population takes place. Inhaling a few droplets of water might then bring in thousands of the little suckers. The whole issue with regard to open radiant systems revolves around amplification: Open radiant systems provide exactly those conditions identified as favorable to amplification.

The Association of Water Technologies gives a figure that 2% to 5% of those "appropriately exposed" develop Legionnaire's. Fifteen to twenty percent of those die. We also have information that over 90% of those exposed contract Pontiac Fever, a mild flu-like disease caused by the same bacterium.

I believe there are enough facts for a reasonable person to make a sound judgement The CDC estimates up to 15,000 legionnaire's cases annually; OSHA estimates over 25,000; others estimate up to 100,000. Estimates of deaths range from 4,000 to 18,000 annually.

If Ms. Stout (quoted in the article mentioned above) is correct and 20 % of Legionnaire's cases are contracted from home water systems, then that comes up to between 6,000 and 20,000 cases annually and between 900 and 4,000 deaths.

Bear in mind that these are estimates of infections from home plumbing systems--most of which do not have open radiant systems.

There are certainly some areas where one might desire better information. Nonetheless, there is a powerful case that open systems probably do significantly increase the already present danger of contracting Legionnaire's from the home plumbing system.

Put it this way: There may be a link or two yet unproved in the causal chain linking open systems to increased disease risk, and, on the level of science, you might not be willing to call the case "open and shut" as of yet. HOWEVER: When it comes to deciding what course of action is prudent and responsible, the circumstantial evidence is overwhelmingly against open systems. Thus, I submit that on the level of policy, the case is indeed "open and shut."

Bill

Mike T., Swampeast MO

Hey Dave...

Guess I could look this up, but you'll probably know.

Is Legionella ph sensitive?

hot_rod

If we look at

elevated temperatures, say above 140, and high chlorine levels, combined with constant circ, some say we may see problems with pex breakdown?

The chlorine and DHW temperatures, especially in DHW recirc systems was a problem for the PB and fittings. They waffled for years on PB in constant circ DHW applications. One day it was OK the next day not, then intermitten recirc was OK, then not. Never really did get a straight answer. Then PB left the market and a trail of lawsuits and expensive repipes in it's trail.

I have read snippets about this (chlorine, temperature and pex life) in the Global Pipe newsletter (from Germany)
It seems to be a concern with the PEX resin folks, as I recall. Keeping in mind European don't chlorinate, I have heard. So the R&D on this will undoubtably be on this side of the pond! Maybe in our customers homes! Ouch! Shiver me crimpers, mate-ee


We need to be careful "fixing" one potential problem at the larger expense of failed tube in years to come!

Does anybody really have all the answers?? Bueller.... Bueller..... anyone.... Bueller. (from the movie Farris Buellers day off)

hot rod

hot_rod

well - that's a deep subject

Legionella need the following:

pH of 5.0 to 8.5

Stagnation

Biofilms

temperatures of 55 to 133 F with the ideal range being 80 to 122 and 98 F being the optimum (what's the human body temp???)

What part of an open system doesn't offer up all four? Fuggetaboutit!

They infest the lung's macrophages, which look just like an Amoeba to them and use them as a nursery until they literally burst at the seams - spewing forth the offspring. In small doses, healthy individuals never know this happened and go on living. With doses large enough to overwhelm a healthy individual's immune system, death can occur. In people whose immune systems are suppressed, pneumonia-like symptoms can set in resulting in death.

I resigned from the RPA committee studying this issue when it became blatantly apparent that the truth wasn't being sought out for considering the outcome of the "standards". Specific questions I posed to those who avidly support open systems were ignored and went unanswered. Suppositions put forth that couldn't be supported by sound factual reasoning and that were challenged also went unanswered.

I submitted documents that detailed the results of five scientific studies in which a percentage of all water heaters tested were found to be positive for Legionella Pneumophila sero group #1 - the nasty strain that causes Legionellosis.

A second document submitted, penned by lawyers, detailed their interest and how they intent to prosecute cases of LD. Guess who's in the cross-hairs? You.

The argument most often heard? "Show me the bodies." Well, here's two for starters in this article on CNN. Do we really need to see them all to know there's a problem that's within our ability to control? Open systems are an amplifier - they can't help but be one.

How can we prevent this bug's ability to survive and thrive within our potable hot water systems? Simply by doing the following (which CIPH missed by a mile when they ignored the system).

#1 - raise the storage temp to 140 minimum (CIPH got this part right)

#2 - install a temperature limiting scald guard device at the point of source set for 133 to 140. (CIPH got this part right too) Why? Stacking temps in water heaters are allowed by codes governing their controls to be as high as 190 F! Let's flat line that outlet temp.

#3 - constant circulation within the distribution system to within a short distance of all points of use. = no stagnation and continued pasteurization of the potable hot water. No bugs will thrive.

#4 - install scald guard devices at ALL points of use where human contact can/will occur. Have the plumbing inspector inspect the system (that's what CIPH missed BTW - it's a system, not just one component)and sign off on the fact that we've installed it to specs. Reduces liability.

Now, let's look at scald guard faucets. They come in three styles: pressure balanced or P-only; temperature balanced or T-only; and pressure/temperature balanced or PT.

P-only are the least expensive and meet codes, but do they do the job adequately? NO. Here's why. They are blind to temperature changes such as seasonal, which in my area ranges from a low of 37F to a high of 85F / unitrol setting changes such as when the HO runs out of hot water too frequently & changes the unitrol - oops, there goes that faucet limit stop temp / stacking temp spikes.

T-only are better in many respects but can be goofed up by sudden changes in pressure and can be too slow to react.

PT are simply the best for protection and should be mandatory in all bathing areas and where children will use hot water. Remember this, 3.1 minutes of contact with 120 degree F water for youngsters will still result in 3rd degree burns. Same goes for the elderly or infirm.

Legionella protection requires the need to incorporate scald guard protection.

Put your money where your mouth is? We did & recently completed a commercial project that incorporates all of the above - on a well water system no less. More to come on that later in CM.

Raise the bar cause I can't limbo that low no more! But, that's just my own personal opinion and as some would say - I'm just a stinkin plumber.

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hot_rod

chlorine

dissapates as water is heated, which has led some to believe the pitting in copper hot water lines is a ditrect result.

Kill me or leaks? I'll accept the leaks first. Chlorine degradation is unproven, although I don't find it a hard leap of faith. Legionella flourishing in potable hot water systems, on the other hand, is a stone cold fact.



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hot_rod

most people

who smoke don't get sick or die as an immediate result, but the dangers are well recognized now. Tweren't always so & I can remember the time when we were kept in the dark by the tobacco companies. Hells bells, I used to be assigned the job of keeping the cigarette decanters filled with various brands during my parent's dinner parties. Dad & I would go out ahead of time to purchase the various brands smoked by the guests they'd have invited. Damn near everyone smoked.

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hot_rod

PAH politician at heart

You're well supported arguments were not, and are not, falling on deaf ears. Trust me. Committies take time to work, ask Robert Bean, don't throw in the towel at the first volley.

You have stated here, that you would not accept a RPA board nomination until the open system issue is resolved and removed from the standards guideline. Yet you, the most well read master plumber on the committe, on this subject, resigned. Sounds like a catch 22 to me. Reconsider please.

I had hoped to sit on the board at the same time and lob spitballs at you

You're not the type to run from a challange. And I'll bet you didn't join the RPA just to cover your wall with awards, and hang with the boys

In friendship

hot rod

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Dave Yates (PAH)

no patience for politics

Sausage and laws - two things no one should be forced to watch being made!

I was ready to stand fast and defend my beliefs. I expected the same from those who support open systems, especially those who make outlandish claims regarding their belief that open systems are just hunky-dory. I backed mine up with hard facts, they would not even answer questions or supply one shread of factual information to support such nonsense such as supplying 100% of a home's A/C by virtue of circulating the incoming potable water through the in-floor tubing.

Then the committee's direction was altered by someone not even on the committee and I was chastised for being a "wordsmith" while no one directed that the reasonable questions I (and others) posed be answered or supported by facts.

I have better things to do than waste my time serving on a committee that allows its members to make claims supporting open systems without requiring they support those claims with factual information.

The CNN report documents two CAP deaths from LP, so there goes the argument about "show me the bodies". Of the 7% average of water heaters that tested positive for LP #1, an open system coupled up to them would have simply offered a veritable banquet opportunity for rampant reproduction.

Open systems are simply stupid and a dangerous practice. Here's the real question: How can an open system not be an amplifier for Legionella bacteria?

You've read the four basic needs above, all of which open systems offer. Hot water flushes don't eradicate the bugs and chlorine dissapates as water is heated and, besides which, it's concentration is too low to begin with for suppressing the numbers of Legionella. Chlorine does not penetrate biofilms very well. Pasteurization at 140F takes 20 minutes of contact time, so exercising the pumps simply re-seeds the system and you already know my arguments about relying on mechanical devices (pump & timer)for safety.

As for why TP being the best scald guard protection? It incorporates both types in one valve and isn't blind to temperature fluctuations.


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Joe_13

Reverse indirects?

Wouldn't a reverse indirect DHW tank offer the best solution? I would think that most DHW tanks sit for part of the day with stagnant water brewing at 120 degrees or less. What about vacation homes where the heaters might be turned off for a few days or weeks to save energy? I'm sure most people do not totally flush the tank and then allow it to come up to temp. At least the tankless coil immediately brings in fresh water. Putting it in a insulated tank with low standby losses seems like a great idea, not to mention you get a free buffer tank to use on a radiant/low mass system. Anyone a faithfull believer in the ErgoMax, Turbomax, or Dunkirk Artesian reverse indirects?