Propane on-demand water heater

Chuck_7

I have never thought much about on-demand water heaters. But then I have never lived in a house with a large family. On the other hand I have stayed at a B&B where we tried to fill up the Jacuzi and ran out of hot water.
I am looking at a water heater for a house that will be for a large family and has a large master bath tub. So an on-demand water heater is looking better. Anyone disagree?????
It will have to be propane.

Unknown

yes

I disagree. Good luck finding an on-demand water heater with the flow rates a large family will require.

Remember output isn't the whole story!

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Ranger

Look at...

...www.rinnai.us

dave connors

on demand

I believe Bosch makes one too.

ScottMP

yes Look

At the flow rates.

Maybe a on demand dedicated to the tub alone and don't go beyond the flow rates the heater will put out. Most wont keep up with the faucets for a large tub.

If you can talk everyone in the large family into only using hot water when no one else in the family is using it ... You'll get unlimited water.

BUT as soon as some one else turns on a faucet or takes a shower or use's the dishwasher or the washing machine ... Fahgetabout it !!

Scott

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Unknown

am I on crack?

I'm not familiar with all the on demand heaters out there, but typically the ones I've seen cap out at less than 5 GPM. are Bosch's or the Rinnai's rated for more GPM?

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D lux_2

rinnai

I took the rinnai course . they had a setup with 2 shower heads worked fine . I have only installed one they had took 2 showers and had the dishwasher and washer going said it was fine . 3/4 copper and a return loop grav. 6 gal tank with a pump to keep 6 gal hot / they did this test before the tank and loop were finished .

dave connors

Bosch 250sx

supposedly up to 6.3 gpm

Jim M

Tankless

> I disagree. Good luck finding an on-demand water

> heater with the flow rates a large family will

> require.

>

> Remember output isn't the whole

> story!

>

> _A

> HREF="http://www.heatinghelp.com/getListed.cfm?id=

> 340&Step=30"_To Learn More About This

> Professional, Click Here to Visit Their Ad in

> "Find A Professional"_/A_

Jim M

Tankless

Wow, Tankless won't handle a large family. We have sold numerous tankless systems precisely for large familys or large consumers of hot water (restaraunts, gymnasiums, hot tubs). The brand we use will provide 8.5 gpm in a single unit and has master/slave controllers for multiple units. Largest we have done is 3 units this gives you 25.5 gpm and 540,000 btuh. My partner, married with three teenage daughters, installed one, says finally on Sunday morning he gets a warm shower.

ScottMP

So Jim ?

What unit provides 8.5 gpm and what is the temperature rise ?

Inguiring minds wants to know ?

what do you mean by a "warm" shower on Sunday morning ? Is that a good thing or bad ?

Scott

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S Ebels

We've had super results

We've installed a lot of Takagi on demand water heaters in a lot of different applications from two person homes to dairy barns.

www.takagi.com has all the specs and some engineering drawings to look at. They have specs and drawings for adding storage tanks for large draws also. Great product!

Pay careful attention to flow rates and temps required and your customer will be happy with the result.

Dave Yates (PAH)

read the ads carefully

note the water temp used to obtain ratings

I'm covering this at ISH-NA on Friday morning.

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ScottMP

exactly Dave.

gpm is only part of the question.

Temperature rise is the other side of the issuie.

Scott

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jackchips_2

I have

a Takagi "Aquastar 240" piped in series with my 50 gallon gas fired water heater. It was done like this so I could heat our swimming pool through a heat exchanger. An added benefit has been continuos hot water.

Before installing the Takagi my wife would drain all the hot water out of the 50 gallon and I would wait for it to recover. Now we have not drawn the hot water down. We are very pleased with the Takagi performance and it will be interesting to see how long it and the 50 gallon unit last.

I may do a little research with a thermometer to see what the temperature leaving the indirect is with one shower valve, two shower valves and then the kitchen sink running. I'll follow up a few times as the weather, therefor the incoming water, gets colder.

Gosh, this must be how ME, Hot rod and Pah must feel? :-))

Jim M

Tankless

> gpm is only part of the question.

>

> Temperature

> rise is the other side of the issuie.

>

> Scott

> _A

> HREF="http://www.heatinghelp.com/getListed.cfm?id=

> 237&Step=30"_To Learn More About This

> Professional, Click Here to Visit Their Ad in

> "Find A Professional"_/A_

Jim M

Tankless

It's interesting we all look at something and have different conclusions about it's operation. Tankless is not a cure all solution for every application. The most important thing is finding out what your customers hot water consumption is. For instance in my partners case he runs two showers with a 75f rise as long as he wants ( warm being a figure of speech but what he needs). If your customer has high flow volumes ie roman tub valves, multiple shower heads, or wants a recirc loop, special considerations need to be made (as with water makers water heaters and coils). But matching systems with customers is part of the service we provide and tankless should be part of our arsenal

Dave Yates (PAH)

exactly

well said

low flow and intermittent flow need to be considered carefully too

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Dave Yates (PAH)

feels good

don't it!(G)

Once you know "it" inside and out, you own it and nobody can take that away.

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Jack_21

On demand

Again, I'm biased towards them. Through the years, every hot water system I have ever lived with has had a "personality". You learn what it can do and you either make a change or you learn to live with it. My Buderus and Buderus indirect is the balls. My Rinnai is the balls and my gas bill dropped 65% since I turned off the boiler/indirect and turned on the Rinnai. And why would I want to size my boiler for DHW rather than for the heating load? When I'm at ISH listening to Dave I cannot understand why I would want to have a water heater (The indirect)that was continuing to make hot water while I am 40 mi away. As a nation, I don't think we can afford to continue to live like that

On demands are all about flow and temperature rise. The Rinnai 2532FFU can produce 8.5gpm but at a very low temp rise. At a 70 rise it will make 4.5gpm all day long. In New England where I live we have 50 ground water...most of the time. I cannot ever get 8.5 gpm of useful temp water here due to the cold ground water. The 2520FFU model will make the same 4.5gpm at a 70 rise and is $200 less than the 2532. All my customers buy the 2520 for residential apps. Roger the rep in FL (assuming he hasn't blown to GA or points north by now) uses the 2532 and gets 8.5gpm. He has ground water temps of 80 though, so it works for his area as his temp rises are so low.

My partner put one in his new "camp" and had a housewarming party. Sun morning, 19 people, 2-2.5gpm showers. Both showers ran simultaneously. Everyone got as long a shower as they wanted at a very satisfactory shower supply water temp (120F) mixed to their desired temp. When both showers were running and someone opened a lav faucet the water pressure dropped a bit but the temp remained the same. When he left the house for the week the unit consumed no gas, but it was ready to go the following weekend. Seems pretty cool to me!

All Rinnai or any of the other on-demand needs to be successful is a mechanic who understands how they work, and represents, applies and installs them so they can do their best.

Mark Eatherton1

A btu, is a btu, is a btu...

and it doesn't matter if its German, Chinese, Japanese, Taiwanese or Maerican. It's STILL just a btu.

The problem with that industry (yeah right, like our boiler industry is perfect....) is that they don't have a uniform standard for rating water heaters. They should ALL be rated for worst case scenarios, like a 100 degree F rise. This way, everyones on the same playing field, and no misleading information is given out.

Having had lived with a tankless (ELM Aquastar, pre Bosch), I can tell you they ae wonderful, provided you're willing to adjust your life style to their availability. Not really that big of an inconvenience.

An interesting note, however. Even WITH my T-50 munchakin, and the 80 gallon upside down (Poisidon) Amtrol tank I have, I'm still seeing fuel savings in the area of 10% during the summer months...

A tankless heater IS a heck of a lot more efficient than the American invention (hot water tank with a hole running through the middle to release LOTS of your hard earned money), but I'm not convonced that they're better than a good combination like I have.

Rating tankless heaters is a simple matter of mathematics.

It's the marketeers playing games with those ratings that irks me.

Which delivers more energy. 1 gallon per minute at a 100 degree rise, or 100 GPM at a 1 degree rise...

You do the math.

ME

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Chuck_7

The house I am looking at will have a multi head shower in (and a jucuzi) the master bath. There will be a kids bath with a standard shower along with washer (which with 5 kids I imagine bing used quite often) and a dishwasher. I picure at least two water heaters.
Here's the big question - what is typical temperature of well water in the western NY?

jackchips_2

c

you'll have better luck getting responses if you go to the top of the page and start a new thread.

Dave_22

WNY

I live in WNY and have a well also. I believe in the winter my well water is in the 50's. Do you have a hot water heat system in the new house? It would be a good place for an indirect- you'd be asking a lot of an on demand for a house with that many amenities.

D lux_2

put in 2

rinnai