# DOE banning multiple shower heads?



## ZL700 (Dec 8, 2009)

http://www.supplyht.com/Articles/Breaking_News/BNP_GUID_9-5-2006_A_10000000000000831250


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## TheMaster (Jun 12, 2009)

ZL700 said:


> http://www.supplyht.com/Articles/Breaking_News/BNP_GUID_9-5-2006_A_10000000000000831250


 
I've often wondered when this would come up.


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## SewerRatz (Apr 25, 2009)

Just have to put in more than one mixing valve per shower head for those that "Need" more than one shower head. This way you will meet the code.

I bet the tankless manufacturers would love to see this pass.


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## ZL700 (Dec 8, 2009)

"I bet the tankless manufacturers would love to see this pass."

Why would you say that?

A 199,000 BTU 83% will feed 2 heads (5 GPM) with room to spare at 70 degree rise forever, a 50 gallon tank runs out in 7 minutes or less with no one getting hot water again for awhile

The way I see it, the tankless companies, the gas pipe manufacturer, the fixture company and most importantly the contractor should like big showers, it means more money for all, except for the few plumbers are more concerned of the homeowners finances than their own earnings.


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## TheMaster (Jun 12, 2009)

SewerRatz said:


> Just have to put in more than one mixing valve per shower head for those that "Need" more than one shower head. This way you will meet the code.
> 
> I bet the tankless manufacturers would love to see this pass.


That will not be allowed. One showerhead per one shower compartment.


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## TheMaster (Jun 12, 2009)

ZL700 said:


> "I bet the tankless manufacturers would love to see this pass."
> 
> Why would you say that?
> 
> ...


You wouldn't need 2.5 gpm of hot water per shower. A showers max flow is 2.5 gpm so why would it need to be all hot?


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## ToUtahNow (Jul 19, 2008)

ZL700 said:


> "I bet the tankless manufacturers would love to see this pass."
> 
> Why would you say that?
> 
> ...


I'm curious how you came up with 7-minutes? 

I believe the normal temperature for a shower is 105 degrees. The water heater is set at at least 120 degrees if not higher so the shower is blended with cold water as well. The first hour rating of a 50 gallon gas heater is around 80-gallons.

Mark


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## ZL700 (Dec 8, 2009)

yea, yea, yea, Ok that was the quick answer, pretend the restrictor is removed or pressure is high

Utah, a 7 minute shower is not over a 1 hour period, so a 1 hour recovery doesnt apply. 

A 50g tank has about 70% capability before it drops below desired temp, thus 120 degrees will hit about 105 and continue dropping at 35 gals of usage. 35 gallons of hot with mixed cold water of 10% will thus give you about 15 minutes in round numbers.

If you read up we were discussing two - 2.5 heads flowing (or 5 GPM), thus the 7 minutes. (in round numbers)


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## TheMaster (Jun 12, 2009)

ZL700 said:


> yea, yea, yea, Ok that was the quick answer, pretend the restrictor is removed or pressure is high
> 
> Utah, a 7 minute shower is not over a 1 hour period, so a 1 hour recovery doesnt apply.
> 
> ...


Thanks for explaining the cold will mix in the tank  You do realize a longer diptube will slow the process.....but that will increase the risk of stacking. Welcome to my world


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## ToUtahNow (Jul 19, 2008)

ZL700 said:


> yea, yea, yea, Ok that was the quick answer, pretend the restrictor is removed or pressure is high
> 
> Utah, a 7 minute shower is not over a 1 hour period, so a 1 hour recovery doesnt apply.
> 
> ...


I read it and disagree with your conclusion. First you are assuming the shower is all straight hot water and not blended water as would be the normal condition. Secondly the "First Hour Rating" is not the same thing as the "First Hour Recovery".

Here is the DOE example of a storage water heater with a "First Hour Rating" of 46 gallon (smaller than a 50 gal).

3-showers 36-gallons
1-shave 2-gallons
1-shampoo 4-gallons
1-hand dish washing 4-gallons

3 showers12×3=36 1 shave2×1=2 1 shampoo4×1=4 1 hand dishwashing4×1=4 Peak Hour Demand =46

Under our code a storage water heater with a "First Hour Rating" of 46 is limited to a one bath home or a one bath one powder room home. Consider an AO Smith GCVT-50L has a "First Hour Rating" of 90 gallons so you can just about double the DOE numbers for the "First Hour Rating" of the 46 gallon water heater.

Mark


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## JK949 (Mar 18, 2009)

First hour rating for the GPHE-50 A.O. Smith Vertex is 126 gal, with a first hour recovery of 92 gal at a 90 degree rise in temperature.


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## ROCKSTARPLUMBER (Dec 14, 2008)

But I like multiple shower heads.


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## ToUtahNow (Jul 19, 2008)

JK949 said:


> First hour rating for the GPHE-50 A.O. Smith Vertex is 126 gal, with a first hour recovery of 92 gal at a 90 degree rise in temperature.


Yes but I was trying to keep it simple. The GPHE-50 has a 90% efficiency rating and I believe the tankless is 83%.

Mark


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## Everflow (Feb 1, 2010)

You can debate back and forth all you want. The biggest flaw a tankless has is GPM. We will not recommend them for anything over a 2 bath house.


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## ZL700 (Dec 8, 2009)

Yes but the point your missing is if the tank has a first hour rating of 90, if you draw more than 90 gallons in that hour, temp will be below the given rise/temp at that 1st hour rating.

Thus 1 hour equals 60 minutes, that 90 / 60 = 1.5

Meaning exceed 1.65 GPM (90/10 mix) continuous over 60 minutes the tank cant keep up or 6 - 7 minute showers (90/10 mix) in an hour, cant keep up.
One thing to remember, tanks are rated on first hour, or gallons per hour tankless are rated on peak GPM, most importantly, followed by GPH

Increase a tank BTU, storage capacity, combustion efficiency or decrease flow rate, 1st hour rises

Tankless increase BTU, combustion efficiency, decrease required temp rise, GPM increases


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## Everflow (Feb 1, 2010)

Oh...The stock answer to all these questions of GPM. Decrease required temp rise. That always gives me a good laugh, I decrease the temp coming out of the tankless, then all I hear is complaining about the temp not being hot enough. A tankless just does not produce enough hot water when the incoming water is cold, and there is nothing that tankless manufacturers can do about it.

Now I'm going to hear the next stock answer put in multiple units.

I like most people think going green is cool, unless that green is coming out of my pocket.


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## ToUtahNow (Jul 19, 2008)

ZL700 said:


> Yes but the point your missing is if the tank has a first hour rating of 90, if you draw more than 90 gallons in that hour, temp will be below the given rise/temp at that 1st hour rating.
> 
> Thus 1 hour equals 60 minutes, that 90 / 60 = 1.5
> 
> ...


I've seen your other posts here and at other sites. I know you have posted you are a specifying engineer and you have taught plumbing classes. I would still like to see your calculations on a 50 gallon water heater with a FHR of 90 gallons only lasting 7-minutes with two showers at 2.5 gpm. Unless I am missing something your calculations are way off. Your figures would probably sell a lot of tankless heaters but they flat out are baseless.

BTW, as a disclaimer I do not dislike tankless heaters and I have specified them as well.

Mark


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## JK949 (Mar 18, 2009)

Tankless manufactures are spec'ing temp rises between 45 and 60 degrees. In California, they are claiming we have 60 degree incoming water temperature in the summer, colder in the winter. That puts us at 120 degrees optimal down to 105 in the winter to figure their flow rates. While that may be adequate, customers generally seem to prefer 130 which taxes the most popular model we deal with. 

To keep things simple, over two showers and you're talking about linking multiple heaters. $$$

The biggest advantage to tankless is space savings. If there is room, Vertex's rule the day.


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## ToUtahNow (Jul 19, 2008)

JK949 said:


> Tankless manufactures are spec'ing temp rises between 45 and 60 degrees. In California, they are claiming we have 60 degree incoming water temperature in the summer, colder in the winter. That puts us at 120 degrees optimal down to 105 in the winter to figure their flow rates. While that may be adequate, customers generally seem to prefer 130 which taxes the most popular model we deal with.
> 
> To keep things simple, over two showers and you're talking about linking multiple heaters. $$$
> 
> The biggest advantage to tankless is space savings. If there is room, Vertex's rule the day.


I had a project in Laughlin that had a cold water temperature of 105 degrees at the meter for much of the summer. The water company would have to open hydrants at the bottom of the hill and let water just run down the street to cool it down.

Mark


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## SewerRatz (Apr 25, 2009)

ToUtahNow what do you think about the Bradford White GX models?

The 25 gallon unit gives 155 gallons first hour delivery, and the 55 gallon unit can give 200 gallons first hour delivery with 82 and 84 gallon recovery at 90º rise respectively. http://www.bradfordwhite.com/images/shared/pdfs/specsheets/119-B.pdf

I installed the GX-2 (25 Gallon) unit in place of twin 50 gallon standard units. The home owner is thrilled. They say it out performs the 2 50 gallon units they had in parallel.


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## grandpa (Jul 13, 2008)

I think many are missing one of the advantages of tankless for new contstruction: use MULTIPLE units, located near the scene of major uses. For example, one for the master bath, one for the laundry, one for other secondary uses....kitchen and other lavs. This brings in the added water-savings and may obviate any need for recircs/


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## ToUtahNow (Jul 19, 2008)

SewerRatz said:


> ToUtahNow what do you think about the Bradford White GX models?
> 
> The 25 gallon unit gives 155 gallons first hour delivery, and the 55 gallon unit can give 200 gallons first hour delivery with 82 and 84 gallon recovery at 90º rise respectively. http://www.bradfordwhite.com/images/shared/pdfs/specsheets/119-B.pdf
> 
> I installed the GX-2 (25 Gallon) unit in place of twin 50 gallon standard units. The home owner is thrilled. They say it out performs the 2 50 gallon units they had in parallel.


 
I have not looked at them yet but that sounds like a winner.

Mark


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## ToUtahNow (Jul 19, 2008)

grandpa said:


> I think many are missing one of the advantages of tankless for new contstruction: use MULTIPLE units, located near the scene of major uses. For example, one for the master bath, one for the laundry, one for other secondary uses....kitchen and other lavs. This brings in the added water-savings and may obviate any need for recircs/


If I was building a new home I would for sure go with a tankless with the exception of the jetted tub.

Mark


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## PLUMB TIME (Feb 2, 2009)

SewerRatz said:


> ToUtahNow what do you think about the Bradford White GX models?
> 
> The 25 gallon unit gives 155 gallons first hour delivery, and the 55 gallon unit can give 200 gallons first hour delivery with 82 and 84 gallon recovery at 90º rise respectively. http://www.bradfordwhite.com/images/shared/pdfs/specsheets/119-B.pdf
> 
> I installed the GX-2 (25 Gallon) unit in place of twin 50 gallon standard units. The home owner is thrilled. They say it out performs the 2 50 gallon units they had in parallel.


Ron, 

I put two of the 55 gallon models in for a job that would have required FIVE tankless units. Been in now for a year an a half and the customer loves them.


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## Protech (Sep 22, 2008)

If you are installing multiple units then you are talking about $4k-$8k. For that price you could install a single solar heater and have free (not cheap) hot water and have installation cash to spare. No need to go around flushing 2-3 heat exchangers every year either.




grandpa said:


> I think many are missing one of the advantages of tankless for new contstruction: use MULTIPLE units, located near the scene of major uses. For example, one for the master bath, one for the laundry, one for other secondary uses....kitchen and other lavs. This brings in the added water-savings and may obviate any need for recircs/


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## Protech (Sep 22, 2008)

How much for the 25 gallon unit? Looks pretty snazzy.



SewerRatz said:


> ToUtahNow what do you think about the Bradford White GX models?
> 
> The 25 gallon unit gives 155 gallons first hour delivery, and the 55 gallon unit can give 200 gallons first hour delivery with 82 and 84 gallon recovery at 90º rise respectively. http://www.bradfordwhite.com/images/shared/pdfs/specsheets/119-B.pdf
> 
> I installed the GX-2 (25 Gallon) unit in place of twin 50 gallon standard units. The home owner is thrilled. They say it out performs the 2 50 gallon units they had in parallel.


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## SewerRatz (Apr 25, 2009)

Protech said:


> How much for the 25 gallon unit? Looks pretty snazzy.


 My cost was around $900 for the unit. List is up there with the standard 50 Gallon power vent.


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## ZL700 (Dec 8, 2009)

Sometimes I read fast and recovery is definitely not the same as rating

Assume 55 gallon tank (GX-1-TW),
78,000 BTU gross input @ 82% operating efficiency 

78,000 x .82 /8.34/ 90 rise = 85 gallon recovery
Bradford White states 84 GPH recovery at a 90 degree rise, so my calc is close

Turbulent mixing of cold with hot water in the tank will reduce the available storage from 55 gallons to about 50 gallons.
Add 84 GPH recovery to 50 Gal storage and you will have a net available hot water draw of 134 gallons for a 60 minute draw (first hour delivery). 

Above is the factual part.

They state 200 first hour delivery in their literature, but what they don’t tell you is that would be at a near 50 degree rise

78,000 x .82 / 8.34 / 50 = 153 GPH recovery + 50 gallon storage = 203 First hour delivery


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## Protech (Sep 22, 2008)

In central Florida, 50 degrees rise is all you need.



ZL700 said:


> Sometimes I read fast and recovery is definitely not the same as rating
> 
> Assume 55 gallon tank (GX-1-TW),
> 78,000 BTU gross input @ 82% operating efficiency
> ...


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## ZL700 (Dec 8, 2009)

Protech said:


> In central Florida, 50 degrees rise is all you need.


And even less at times


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## SewerRatz (Apr 25, 2009)

ZL700 said:


> Sometimes I read fast and recovery is definitely not the same as rating
> 
> Assume 55 gallon tank (GX-1-TW),
> 78,000 BTU gross input @ 82% operating efficiency
> ...


The GX-1 or 2 cooks the water to 180º F and it has a tempering valve built onto the tank to limit the outlet temperature to 120º Which is how they can give you 200 Gallons for the first hour.


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## ZL700 (Dec 8, 2009)

SewerRatz said:


> The GX-1 or 2 cooks the water to 180º F and it has a tempering valve built onto the tank to limit the outlet temperature to 120º Which is how they can give you 200 Gallons for the first hour.


Imagine the lousy efficiecy doing that??????

130 degree temp rise? (50-180)

How comfortable are you with a small mix valve betwwen 180 degree water and the kid in the shower?


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## ZL700 (Dec 8, 2009)

ToUtahNow said:


> I've seen your other posts here and at other sites. I know you have posted you are a specifying engineer and you have taught plumbing classes. I would still like to see your calculations on a 50 gallon water heater with a FHR of 90 gallons only lasting 7-minutes with two showers at 2.5 gpm. Unless I am missing something your calculations are way off. Your figures would probably sell a lot of tankless heaters but they flat out are baseless.
> 
> BTW, as a disclaimer I do not dislike tankless heaters and I have specified them as well.
> 
> Mark


40,000 x .72 / 8.34 / 70 rise = 49 GPH Recovery

49 x .25 (15 minutes) = 12.25 Gallons (15 min recovery)
12.25 (Gallons/15 minute recovery) x .9 (intial tank burner delay) = 11
11 + 46 = 57

57 gal (storage + 15 minutes of recovery) / 5 GPM (2 heads) = 11 minute shower, within a 15 minute period

That’s the quick answer, I didn’t factor mix

Sorry for posting slightly inaccurate figures thrown from a cloudy head.


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## SewerRatz (Apr 25, 2009)

ZL700 said:


> Imagine the lousy efficiecy doing that??????
> 
> 130 degree temp rise? (50-180)
> 
> How comfortable are you with a small mix valve betwwen 180 degree water and the kid in the shower?


 Just as comfortable as I am with 180º water and the mixing valve installed in restaurants, hotels and other places that have to have 180º water for their kitchen or laundry area, as well as tempered water for the showers, or hand wash sinks.


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## ZL700 (Dec 8, 2009)

SewerRatz said:


> Just as comfortable as I am with 180º water and the mixing valve installed in restaurants, hotels and other places that have to have 180º water for their kitchen or laundry area, as well as tempered water for the showers, or hand wash sinks.


Yes, but much different grade of mix valves and they are designed to fail cold


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## SewerRatz (Apr 25, 2009)

ZL700 said:


> Yes, but much different grade of mix valves and they are designed to fail cold


Do you really think Bradford White will not use one that fails to cold? Its the same damn valve I have installed in restaurants to provide tempered water to the rest rooms. I honestly can not believe you would think a manufacture would design a water heater that can fail in a way that would cause scalding.


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## ZL700 (Dec 8, 2009)

SewerRatz said:


> Do you really think Bradford White will not use one that fails to cold? Its the same damn valve I have installed in restaurants to provide tempered water to the rest rooms. I honestly can not believe you would think a manufacture would design a water heater that can fail in a way that would cause scalding.


Do you understand what fails to cold means?

It means it wont go full hot on a failure and scald someone

So I looked it up and the valve on the BW is ASSE 1017 which means it shuts off if cold is lost. ASSE1017 are the lowest priced mixing valves out there and not to be confused with 1016's or 1070's such as made by Powers, Symmons or Watts, that would be placed in commercial applications

According to ASSE (American Society of Sanitary Engineering)
"ASSE 1017, does not address final temperature control at fixtures and appliances. It is concerned with valves used at the source of hot water for distribution to the supply system, and therefore allows wider variation of the outlet temperature at higher flow rates. 

ASSE 1017 listed devices should never be used to deliver water directly to the user. These valves should be used in combination with an ASSE 1016 and/or ASSE 1070 listed devices."

Well how safe is that? 

BTW, the residential gas valve on the heater we have been discussing will not go over 150 degrees. The mix valve was added to be proactive in the future legislation and requirement of storing water at 140, to eliminate bacteria growth


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## Titan Plumbing (Oct 8, 2009)

DOE needs to keep their nose out of things................


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## ZL700 (Dec 8, 2009)

Choctaw said:


> DOE needs to keep their nose out of things................


I second that, the ADA disabilities folk will definitely be involved since many showers are specially outfitted.


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## Protech (Sep 22, 2008)

The valve on the that heater will only fail to cold. I know this from experiance.



ZL700 said:


> Do you understand what fails to cold means?
> 
> It means it wont go full hot on a failure and scald someone
> 
> ...


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## GREENPLUM (Jul 27, 2008)

TheMaster said:


> I've often wondered when this would come up.


 
me too, now I will let the customer know they better get while the gettins good times a tickin


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## Turd Herder (Jun 4, 2010)

Regarding this law, I read it on Friday, and the language seems specific to prepackages systems, like the grohe shower wall, or those packages you see at home depot with a handheld and a shower head on the same unit. I dont see how the DOE would have jurisdiction within building codes, but i dont know. I knwo that lead law passed and all the lead stuff is off the shelves in the supply houses, but I have yet to hear of any sort of enforcement on job sites that is lead related. We will see. I know all the supply houses are panicking, but i am really not worried about it.
Scott


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## Redwood (Sep 8, 2008)

Turd Herder said:


> I dont see how the DOE would have jurisdiction within building codes, but i dont know.


It's pretty simple...

The states adopt a code and it may have local amendments that cannot weaken the adopted code...

So that says the state trumps your little town or, county...

Who do you think trumps the state?

Could it be the fed?:whistling2:


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## GREENPLUM (Jul 27, 2008)

well, what happened? 



anybody


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