OT: Separate hot and cold valves on kitchen taps save energy.

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On 6/6/2011 1:17 AM, Lew Hodgett wrote:

Mea culpa. Tip of the slung/typo ... that was obviously supposed to be three 240v circuits per unit.

Ever pay to upgrade an existing home to a 300 - 400 Amp service to handle the electrical requirements of a whole house tankless unit?

The decision, and cost effectiveness, is based on many factors, including the ambient temperature of the ground water in your area.

This is the wRec after all, where those who have no experience with a product wax eloquent ....
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"Swingman" wrote:

I just spec the stuff, not buy it.<G>. ---------------------------------

"Tankless" first hit the marine market in the mid 1980s.
Propane fired, it was a natural; however, a couple of improper installations let to some deaths as a result of CO poisoning.
The liability suits forced the manufacturer into bankruptcy and that was the end of "Tankless" for the marine & RV markets.
Bosch was one of the first 12VDC controls from their units to make marine installation all but impossible.
The rest of the suppliers followed suit.
(BTW, had resolved the issue for my boat).
As far as reducing water waste to get hot water to the faucet, sailors solved the problem a long time ago.
A simple On-Off valve piped on the hot water side the directs the water back to the potable water storage tank solves the problem.
Open the valve, the water pump kicks on, the "tankless" heater kicks in and a few seconds later, hot water is at the faucet, ready for use.
Problem solved.
Not practical for shore side, but a standard configuration for the cruising sailor.
Lew
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"Lew Hodgett" wrote in message
"Swingman" wrote:

I just spec the stuff, not buy it.<G>. ---------------------------------

"Tankless" first hit the marine market in the mid 1980s.
Propane fired, it was a natural; however, a couple of improper installations let to some deaths as a result of CO poisoning.
The liability suits forced the manufacturer into bankruptcy and that was the end of "Tankless" for the marine & RV markets.
Bosch was one of the first 12VDC controls from their units to make marine installation all but impossible.
The rest of the suppliers followed suit.
(BTW, had resolved the issue for my boat).
As far as reducing water waste to get hot water to the faucet, sailors solved the problem a long time ago.
A simple On-Off valve piped on the hot water side the directs the water back to the potable water storage tank solves the problem.
Open the valve, the water pump kicks on, the "tankless" heater kicks in and a few seconds later, hot water is at the faucet, ready for use.
Problem solved.
Not practical for shore side, but a standard configuration for the cruising sailor.
Lew
============= Long pipes and large system pockets (manifolds) are the problem with most hot water distribution systems. Right at the tap sounds good but hasn't proven easy to implement.
--
Eric


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On 6/7/2011 8:23 PM, Eric wrote:

You're right about the long runs, but I'd argue that a PEX remote manifold, if located/done correctly, should improve your delivery system even in those cases. As I said in the beginning, easier to do in new construction, mostly difficult, and usually expensive to effect in most retrofits ... which is why it isn't often done, and IME results in the biggest cause of user dissatisfaction with tankless installations.
Close to the endpoint (your "right at the tap") is pretty much how Europe has operated for decades, and very successfully. Pumps and a loop system, if properly implemented, also seem to work very well, although I haven't built one that way personally.
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"Swingman" wrote in message
On 6/7/2011 8:23 PM, Eric wrote:

You're right about the long runs, but I'd argue that a PEX remote manifold, if located/done correctly, should improve your delivery system even in those cases. As I said in the beginning, easier to do in new construction, mostly difficult, and usually expensive to effect in most retrofits ... which is why it isn't often done, and IME results in the biggest cause of user dissatisfaction with tankless installations.
Close to the endpoint (your "right at the tap") is pretty much how Europe has operated for decades, and very successfully. Pumps and a loop system, if properly implemented, also seem to work very well, although I haven't built one that way personally.
====== I could see using a low temperature preheat (maybe NG or solar) to take the edge off the initial water heating and then a small (maybe electric) booster to give the final temperature at the faucet. Probably too much installation expense though.
I have many of my runs disconnected from my hot manifold to keep more frequent circulation going in the trunk runs. I was waiting so long for hot water it was painful. I want to put my air handler on the end of that run yet, to keep hot water close to faucets, except it will not help in the winter and the legal limit of 60C makes an upstairs warm-up each morning a little too lengthy. I did add it to the feed of the manifold and that cut a few seconds off the time delay. I still have access to most of my PEX as the basement ceiling is removable tiles or open. Not done experimenting yet.
The PEX really puzzles me over my old house copper system. I have less length to the farthest faucet, and the PEX is supposed to be smaller ID and it still seems to take double the time the copper house did for hot water to hit the end faucet??? Maybe I am just watching too closely. It also seems to cool off much faster than copper pipe so you start with room temp every time. I was thinking it should be the other way around. Meanwhile a neighbour installed all copper and a circ pump and has hot water within 2 seconds anywhere. GRRRRR...
--
Eric


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Did you ever go back, as a check, and re-spec your house as if were a new installation?
I don't think they were strictly for builder accounts, but my suppliers had downloadable spreadsheet based software that would allow you to put in all your parameters, ambient ground water temps, list all bath and kitchen fixtures and their flow requirements, etc., and spec a general idea for a recommended tankless unit.
Might give you a start point in sussing out the reasons .... Just a thought.
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"Swingman" wrote in message wrote:

Did you ever go back, as a check, and re-spec your house as if were a new installation?
I don't think they were strictly for builder accounts, but my suppliers had downloadable spreadsheet based software that would allow you to put in all your parameters, ambient ground water temps, list all bath and kitchen fixtures and their flow requirements, etc., and spec a general idea for a recommended tankless unit.
Might give you a start point in sussing out the reasons .... Just a thought.
--

I am not sure what problems you think I have but I did talk with the Rinnai
engineers today about their flow sensitivity cutoff at 0.6 gpm and their
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Eric presented the following explanation :

Circulating pumps would seem to defeat any effort to reduce power usage as they keep sending hot water around the loop to cool and then be reheated even when there is no usage so instead of wasting one pipe full of cold water that heat is being lost all the time. Of course the water is saved but the heat (heating power ) is lost. Choice is on the user I guess.
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"John G" wrote in message
Eric presented the following explanation :

Circulating pumps would seem to defeat any effort to reduce power usage as they keep sending hot water around the loop to cool and then be reheated even when there is no usage so instead of wasting one pipe full of cold water that heat is being lost all the time. Of course the water is saved but the heat (heating power ) is lost. Choice is on the user I guess.
============== Definitely! except in the winter the heat displaces some home heating needs anyway. and costs nothing. Our NG is much cheaper than elect. anyway.
Either N.America will take a step down in their standard of living, down to Europe's standards using tankless, the tankless will improve from years of development in Europe, or disappear as a bad sales joke to extract money from our pockets.
Here is one manufacturer's solution. Check out page 33 http://www.rinnai.us/documentation/downloads/V_Series_Indoor_25xx_U245-3250x0100_revised_A.pdf Get a tank for your tankless water heater. Now you can spend the money over and over again!
--
Eric



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There's a device called the 'hot chillie' which, when the hot water tap is turned on, pumps it back through the cold water line until it's up to temperature. It's only for a single tap but is a neat idea for long runs.
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On Fri, 17 Jun 2011 10:52:58 GMT, scatter

I don't understand. When the hot water faucet is turned on, that water comes out the tap. The cold water faucet isn't open. What does the pump send back? And if something's being sent back in the cold pipe, what happens if both are opened for some strange reason, like warm water? Or does this only work down there?
I watched the movie _Australia_ last night and it was fantastic. Tears in me eyes and all that. http://www.imdb.com/title/tt0455824 /
-- Happiness is when what you think, what you say, and what you do are in harmony. -- Mahatma Gandhi
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On 6/17/2011 9:11 AM, Larry Jaques wrote:

Just installed one of these in the last kitchen we built:
http://www.insinkerator.com/dispensers/index.shtml
Pretty cool ... or hot, whichever you desire!
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On Fri, 17 Jun 2011 17:20:18 -0600, Swingman wrote

I have some experience with the hot water dispensers. These things are great for getting that hot cup of tea or what ever without using the microwave. The one I personally have is connected to the output of our RO water system.
Avoid any units where the tank is connected directly to the dispensing valve (generally the cheapest ones available). The one I first installed and those installed by several others locally all have died horrible deaths within a year or two. Usually the valve explodes or the tank thermostat dies. They also have the tendency to spit hot water regardless of where the temperature is set.
The preferred units have a remote (1-2+ quart) tank which is better insulated and generally of higher quality. Pay attention to the valve. More money spent here means less plastic. Our current Kitchen-Aid unit (about $300) is the cats meow.
At my day job, they use the cheap in-sink-erator types in the kitchens and they last about 6 months before breaking. Either they have a large stock of these or some kind of contract because they keep buying them...
As to the hot water loop, the only solution I see that really works without wasting lots of power is to install a water heater (5 gallon or so) at the sink. The trick is to have this fed from the hot water line so by the time the tank is running low on heat, the 'real' hot water has begun to arrive. You need to consider the energy used and compare that with the recirculating pump approach and also consider that this only works at a single point whereas the recirculator can cover a whole house. $0.02
-Bruce
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Back in 1955 somebody was thinking because the 40 gallon hot water tank is directly, and I mean directly below the main bathroom. That particular bathroom sink has, what I would call, instant hot water... so does the tub and shower. Now the kitchen, on the other hand, is at the opposite end of the house. Maybe they weren't thinking that day? <G>
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On 6/18/2011 9:30 AM, Bruce wrote:

This particular faucet fixture is hooked up to both an InstaHot (?), and chilled water unit.
On a custom job I don't buy the appliances, I just build the kitchens and supervise installation of the clients choice in hardware and fixtures.
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It sounds like a _pump_ connected from the hot line, to the cold line. fore= they get to the faucet/valves.
On a pressure drop in the hot line (when the faucet is opened), the pump turns on and draws water out of the hot line, forcing it into the cold one. More-or-less making the cold water line the 'return' of a recirculating hot-water system.
When the _water_temperature_ coming into the pump rises to a threshold value, the pump shuts off.
In a 'simple' installation, this will get hot water to a 'slightly open' faucet as quickly as if the faucet was turned 'all the way on'.
If there is an 'anti-backflow valve' installed between the pump intake and the faucet valve, then one can use a bigger pump -- one that pulls a net suction on the hot-water supply, and thus moves the water faster than a full-open faucet would. This, however, leads to the 'counter-intuitive' situation of turning on the hot water, and more-or-less _nothing_ comes out until the water is up to temperature.
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Its an electronic system that senses taps opening and water temperature. No water comes out of the hot water faucet until it's up to temperature. It gets pumped back into the cold water line - it saves water without eating too much power (which can be a big deal during our droughts).
Here's a page showing one. http://www.mrsolar.com.au/water-saver.htm
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wrote:

Is all of your hot water line insulated?

And it costs him $40/mo for the extra electricity or gas to do that.
-- Fleas can be taught nearly anything that a Congressman can. -- Mark Twain
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"Larry Jaques" wrote in message

Is all of your hot water line insulated?

And it costs him $40/mo for the extra electricity or gas to do that.
================== Apparently the costs are very small. If you listen to the sales people it saves money on water bills not running the taps to get hot water up from the depths of hell. The units have timers on them and additional heat in the house costs nothing in the winter.
http://www.google.ca/search?source=ig&hl=en&rlz=&=&q=grundfos+circulating+pump&aq=2&aqi=g10&aql=&oq=grundfos
--
Eric


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"Eric" wrote in message

Is all of your hot water line insulated?

And it costs him $40/mo for the extra electricity or gas to do that.
================== Apparently the costs are very small. If you listen to the sales people it saves money on water bills not running the taps to get hot water up from the depths of hell. The units have timers on them and additional heat in the house costs nothing in the winter.
http://www.google.ca/search?source=ig&hl=en&rlz=&=&q=grundfos+circulating+pump&aq=2&aqi=g10&aql=&oq=grundfos
==================== Here is a newer unit that has circulation pumps and controls built right inside the unit. Also a hi-efficiency unit with condensing heat exchangers. Looks like a newer and more modern unit than the Rinnai (supposed to have been top of the tech. at the time) I bought two years ago.
http://www.navienamerica.com/PDS/ftp/NavienCondensingTankless/NR_NP/Installation_Manual/TanklessGasWaterHeater (NR-NP)-Installation.pdf
--
Eric


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