Tankless-luke warm shower

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Redwood

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And you reply to this?
Health hazards from a tank type water heater!

http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2094925

"There are two opposing risks when it comes to water temperature inside domestic water heaters; exposure to Legionella, the bacteria responsible for Legionnaires’ disease (pulmonary legionellosis), and the risk of scalding. In 1986, this dilemma was the subject of an editorial in the Canadian Medical Association Journal (1). A few months ago, Safe Kids Canada launched a media campaign aimed at preventing scalding by lowering domestic hot water temperature to 49°C at the tap (2). Among the means considered to reach this objective, Safe Kids Canada, with the support of some public health organizations, suggests and seems to favour lowering the temperature setting of domestic hot water heaters to 49°C."

"Like other authors (3,4), including the World Health Organization (WHO) who published a recent monograph on the Legionella problem in drinking water (3), we believe that there is evidence for the transmission of legionellosis through the drinking water distribution systems in private homes. This is a serious illness associated with high death rates (up to 12%). Primary groups at risk (the elderly, smokers, the immunocompromised and patients suffering from chronic respiratory illnesses), are groups who include a large proportion of the population at home. Although we support prevention against tap water scalds, we are against setting water heater thermostats at 49°C because we believe this could facilitate proliferation of Legionella inside the tank and increase the risk of legionellosis."

More of the same here:

http://customer.honeywell.com/Water...revention/Legionella+in+Your+Home/Problem.htm

Key Facts

According to the CDC, Legionella bacteria has a broad range of potential growth. “Legionella bacteria exist in the biofilm on the inside of pipes. Legionella grows rapidly between 77°F and 108°F.†Although it may seem feasible to raise the water temperature to 140°F, this leaves the water in the scald temperature range.†(22)

The International Plumbing Code Section 424.4: states, “Shower and tub/shower combination valves shall be balanced pressure, thermostatic, or a combination of balanced pressure/thermostatic valves that conform to the requirements of ASSE 1016 or CSA B125. Valves shall be equipped with a means to limit the maximum setting of the valve to 120°F, which shall be field adjustable in accordance with the manufacturers’ instructions.†(22)

“When a residential water heater is used, the codes do not limit the temperature to 140F, so it is not uncommon to find water at 160 degrees F.†This temperature will scald a child with third-degree burns in only .25 seconds. (22)

How common is Legionella bacteria in my hot water tank?

“In Quebec, a study of 211 homes (178 electric water heaters, 33 oil or gas water heaters) found Legionella contamination in 40% of electric water heaters. No water heaters using fossil fuels were contaminated. The authors concluded that, because of design variables, use of an electric water heater was the most significant factor leading to Legionella contamination in hot water in the home.†(28)

What are the affects?

Occurrences of Legionellosis have happened while people have been exposed to a infected water source and inhaled contaminated water: cooling towers, whirlpools, bathtubs, showers or even at a steamy faucet. Legionella has been shown to most greatly affect people whose immune system is low. For example in a hospital setting, patients that are most susceptible to Legionella infection include: cancer patients who are in radiation or chemotherapy treatments, organ-transplants, HIV, elderly and surgical patients. Severe Legionnaires’ disease has an overall mortality rate of 10% to 30% (1-3), and 30% to 50% of patients require admission to an intensive care unit (1-4) Additional source: Center for Disease Control and Prevention.

Now you have really outdone yourself in your twisting of facts and information resources. Your post is so full of incoherant ramblings of quoted misapplied information that a person reasonably educated could hardly understand it.

I propose that we bestow the title of "Google Boy" upon you.

This is a title that we give to those with a total lack of subject knowledge that manage to post "copy & paste" a long post that looks very knowledgable on the surface until a knowledgable person attempts to read the assembled drivel.


Simply put Legionella Bacteria is present in water. Usually in small quantities that have a miniscule chance of causing a problem. When water is stored at a temperature in the ideal growth range the small amount present can multiply.

The use of a tankless water heater will not do anything to the bacteria to kill it and infact if there is a recirculation system may keep it in the ideal growth range just like a tank type water heater.

The solution is simple for a tank type water heater and that is to raise the temperature in the tank to 140 degrees where the Legionella Bacteria will be killed then youe a tempering valve on the outlet to lower the temperature to 120 degrees for safe use.

There it is a few simple paragraphs that said more than all the drivel you posted...
Could it be that I know my subject matter and am qualified to post about it?
 

SewerRatz

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Now back to "the code". Our friend Mr. Rat (a professional plumber who takes pride in following the code) installed a tankless sytem in a home that had three full bathrooms. He knew that a single tankless system would not supply "hot water" to all three showers when they were run simultaneously. He made the customer sign a disclaimer for that job. Obviously, the installation was permitted and inspected. Obviously, Mr. Rat knew that while the installation met code, it would not provide "hot water" to all fixtures at the same time.


So now the plumbing instructor should answer some serious questions.

Was Mr. Rat considered to be a hack?

Was Mr. Rat following "the code"?

Was the local plumbing inspector incompetent (or worse)?

If Mr. Rat has violated "the code", his customer signed disclaimer will not hold up in court since the agreement violates state law.


Just wondering if your interpretation of "the code" is a valid one. Maybe you should try to have Mr. Rat's plumbing license pulled for not "following the code"!

Sad part about Tankless heaters is the code does not address properly sizing the heater as of yet. Having them singing the disclaimer that I had informed them the system the want installed is not the one they where advised by me to install. It has help up in court as part of the contract, and some of the people did have me come in and install the system as advised. Others changed their usage habits as well as installed flow restrictors everywhere. 1 gpm shower heads .5 gpm aerators and so on. Just so the single unit can handle their demand. Once the code address this issue then I can tell the customer sorry I can not install this the way you want it installed.

Now for restaurants that go tankless do a hybrid set up there. We have two units one direct feeding the bathrooms each with a .5 gpm aerator. The second tank is tied into a 180 Gallon storage tank with recirculating pump and a thermostat on the tank maintaining the water to the required 160 degree water if they use a chemical sanitizer, or to 180 degrees if they just use a hot water rinse on their dishwasher. Granted the second set up is a tankless boiler running at 400,000 BTU but can handle the large demand of the restaurant.
 

Redwood

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Laddy Boy's Credibility?
laugh-1.gif

Answer the Questions!
 
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Ladiesman271

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Ladiesman,

I'm not against tankless heaters (I may go tankless myself next time due to severe space restrictions) but I do have a question on your numbers.

You mentioned that your system is rated at 2.09 GPM output at, I believe, 75 degree temp rise and you have also stated that you can run multiple showers at the same time.

That doesn't seem to add up and I'm wondering how you achieve this? Given that a low flow showerhead is rated at a higher GPM that the unit, how can you run two at once?

The only thing I can think of is that each shower uses some cold and some hot so you might be able to squeak by with two running but it still doesn't seem quite right, particularly for those who might like hot showers.

Also, how do you find it works when you have someone in the shower and a sink calls for hot water on full? (filling sink to do dishes, for example) Is it able to keep up?



As a follow up to that question, I measured everything with that scenario.

1. Typical water temperature that I prefer was measured at 105 degrees. No surprise there.

2. Incoming water temperature is around 42 degrees (winter low).

3. Incoming water pressure with nothing turned on is 71 psi.

4. Tankless heater is an older Aguastar gas tankless with 125,000 BTU maximum.

5. Thermostat set to 120 degrees nominal.

6. 2.5 gpm flow shower head, standard old style three knob valve system.

7. 1.0 gpm maximum flow from kitchen fixture.

8. Normal shower setting (105 degrees) would be about 1/3 cold mixed with 2/3 hot with winter incoming water temperature (42 degrees).

9. Fixed 3.5 gpm flow restrictor was not removed from tankless heater.



I did perform a hot water capacity test in the manner that you described.

1. Hot water in the shower set to full ON with no cold mixed in.

2. Hot water in the kitchen sink set to full ON with no cold water mixed in.

3. Ran water to cool down the tankless unit unit until a stable temperature was observed.

4. Temperature of the hot water in shower and at the kitchen sink went down to 98 degrees and stayed there.
 

SewerRatz

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Sad part about Tankless heaters is the code does not address properly sizing the heater as of yet.

sjsmithjr has made a post in anther thread https://terrylove.com/forums/showpost.php?p=184390&postcount=78 that made me do some more research in the Illinois plumbing code.

The Illinois plumbing code does not address the proper sizing of a tankless water heater directly like Florida does. But there are a couple parts that do help determine the proper size. For showers the maximum temperature is 115 degrees. For kitchen sinks the minimum temperature is 120 degrees. So with that in the code it addresses that the tankless system must be properly sized, or designed to be able to deliver these temperatures. With this information I contacted an Inspector and he informed me that he has failed installations that do not deliver 120 degree water to the kitchen sink while other fixtures are running. So now I need to write a couple letters to a few people explaining to them that they ether have to install the second tankless unit or ensure they are using low flow devices on their shower and sinks to ensure their single unit can meet the code properly. As for future installs I will insist on properly sizing the system for the demand to meet the code.
 
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