HOT WATER ON DEMAND, HEATERS

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condensing furnaces and water heaters dont use a chimey they exhaust thru PVC pipe thru the wall at a very low but slightly warm temperature.
condensing is more efficent than tankless, if you doubt this just hold your hand in a standard tankless exhaust:) get the burn cream ready you will need it
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I didnt state anything different on condensing systems. There are tankless condensing, how do you think a 94 EF rating is acheived, 94EF the highest rating of any water heating system. One of the highest rated tanks I know of is my AO Smith Cyclone a condensing commercial unit. It is in no way more efficient than my cheapy bosch non condensing tankless, Read the EF number on AO, if you can find it, because they hide the sad truth.
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one of the AO Smith condensing water heaters get the fed energy credit.
thats a wonderful tax break
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Dumb, completely dumb you are.
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<stuff snipped>

<I know what a British Thermal Unit is thankyou. To condense water you EXTRACT energy. (This how we get more than 100%) To evaporate water you add energy. Try to keep up.>
You're a puzzler alright, Harry. You've got this right, but you're so wrong about your world history.
This apparent violation of the laws of thermodynamics actually happens to be true. The trick to being over 100% efficient comes from condensing the flue gases to BELOW the input temperature of the fuel and air it's burning. As Harry stated, it depends on (ironically) having cold incoming water that's able to cool the exhaust gases (and water vapor) to below room temperature, extracting the energy of the room temperature air and fuel. So no, Carnot is not turning over in his grave over this perfect engine that he could only dream of, but he would be mightily impressed by such efficiencies even if they involve a little slight of hand like extracting latent heat energy (which it can only do because of the differential between inlet water temperature and room temperature.
Now we'll deal with your rabid Americaphobia, a disease so far progressed that you've lost your ability to deal with the subject rationally.
-- Bobby G.
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You both are wrong, standardised testing in the US for boilers and furnaces measure Btu per hour input and Btu per hour output , and nobody has even got to 99% yet. Net Btu input is still more than Net Btu output, thats a fact. You of course save energy condensing the moisture out of the combusted gas, about 13-15%, Net output still is below input. The most efficient heat is unvented , they are 100%, there is no exhaust but a downside is they can kill you easily.
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wrote:
<stuff snipped>

<You both are wrong, standardised testing in the US for boilers and furnaces measure Btu per hour input and Btu per hour output , and nobody has even got to 99% yet. Net Btu input is still more than Net Btu output, thats a fact. You of course save energy condensing the moisture out of the combusted gas, about 13-15%, Net output still is below input. The most efficient heat is unvented , they are 100%, there is no exhaust but a downside is they can kill you easily.>
You might want to read up on this, because I was surprised when I did because I also thought you can't get more energy out than you put in and 101% ratings were impossible.
The trick is that you're exhausting cooler air than the incoming air because of the heat exchanger's ability to cool down the exhaust way below room temperature and extract the heat energy that was required to bring the fuel and air to room temp. When the exhaust is below room temperature it means that energy has been removed from it and reclaimed *somewhere*.
True, it's not really the heat energy produced by the combustion process, but it is heat energy, and adding it into the mix is what propels the numbers to seemingly impossible "greater than 100%" efficiency. As Harry noted this trick only works well if the inlet temp of the water is very low, allowing it to cool the exhaust below the temperature of the incoming fuel and air and thus condense the water vapor back to water, recovering the energy it took to change water from a liquid to a vapor in the first place. The "trick" is the cooler than room temperature exhaust whose heat has been transferred to the incoming cold water, requiring less energy to heat it to usable temperatures. It's quite the engineering marvel, I think.
-- Bobby G.
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Not true, the rating-testing your heating system has been subjected to is done by measuring Btu input, and Btu OUTPUT. They measure it , the condensing effect is figured is in the rating. As i said it equals about10-15% gain, and doesnt bring it over 100%, or 99%
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I'd say both you and Bobby G have valid points. I can see how a condensing heating system could theorectically achieve greater than 100% efficency. The essential point here is that the extra heat would come from heat energy contained in the air and fuel that go into the heater. If you cool the exhaust gas down to say 33 degrees, you could extract out heat that normally would be wasted. I can see this in a theoretcial or lab experiment application, but doubt it's possible in a residential boiler.
What Hary claimed in the context of this discussion was that this greater than 100% efficiency was available in gas boilers today. I'd like to see Harry provide a data sheet for one that we could buy for a typical house.
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On Tue, 23 Nov 2010 06:37:49 -0800 (PST), snipped-for-privacy@optonline.net wrote:

"Cool down" implies that it was "warmed up" to begin with. How did that happen?

I'd want to see the method used to measure the efficiency, too. No marketeering allowed.
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On Nov 23, 8:37am, snipped-for-privacy@optonline.net wrote:

There are none over 98% efficient, even Englands rating agency Sedbuk states so. Theory is all well and good , actual products are what matter. To me its also illgoical that you can get more than 100% out of burning a fuel, it takes energy to condense that vapor, its not free, and exhaust temps prove energy is wasted on condensing units. its really pointless arguing, his own counrtys rating agency disputes his claim and he refuses to see that fact.
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Im tired of your hearing your lies and stupidity, educate yourself, post one just one manufacturer that sells a SEDBUK Certified over 100% efficient heat plant fired by fossil fuel, or one 99% 98% 97% 96% 95% 94% 93%. You cant. Post just one tested by SEDBUK England, your own governments efficiencys standards system.
UK SEDBUK - Standards Efficiency Database for Boilers in the UK. www.SEDBUK.com
Your own, UK, certified testing standard, you are a nuts to keep this crap up because none are certified over 100%, none are even 91%. Your rating is more conservative than our US rating, read it and please stop the missinformation.
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Hang it up Harry your to old for this. SEDBUK shows no Warmflow over 90.4% Thats your UKs agencys ratings. But just to show you you can`t even read a simple spec sheet . The Warmflow GS 25a is a Sedbuk A class. It has an input rating of KW 25 output KW 24.6. Now you simply take out your pencil, sharpen it, get some clean paper and subtract the two numbers and you will see your spec sheet shows it to be 97.6% efficient. Just what I said that 98% is the high and nothing is at or over 100%. Its real simple to grasp Harry, output is less than input. Hey Harry, I own the Brooklyn Bridge, I will sell it to you real cheap
Try snipped-for-privacy@warmflow.co.UK
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. The Warmflow GS 25A is second on Sedbuks test list of Warmflow boilers. It is up to date, is it rated by Sedbuk 88.7% . Warmflow rates it 97.6% and you still think its over 100% Quit making up lies. You didnt eve post Warmflows most efficient unit.
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I'm with you Mr. Ransley. I did a bit of googling and came up with this nice explanation of how you get 100%+ efficiency:
http://www.blesi-evans.com/102%20percent%20efficiency.pdf
It's exactly as I tried to explain to Harry many posts ago. You can get to 100%+ theoretically or in a lab type experiment by condensing the exhaust gas down to temps lower than the incoming combustion air and fuel. So, you not only get all the heat from the combustion, but you also extract the heat that the air and fuel had before it was burned. Take incoming gas at 50F and incoming combustion air at 50F and extract all the heat so that the flue gas is at 35F. Now, you've achieved over 100% efficiency. Only problem is, it's totally meaningless in the real world of residential or commercial boilers. An example of where it would be effective if you had an industrial process where you actually needed to heat up a fluid that was 10F. Then you could transfer the flue gas heat to it, and cool the flue gas down to 35. In the case of a home boiler, there is no place colder than the 50 ambient to transfer the remaining heat from the flue gases to. Another way of looking at this is that you could get free heat out of the incoming gas and air without burning it all by transfering the heat via a heat exchanger to some other fluid that is at lower temp. The only problem is that in virtually all boiler applications, there is no such other lower temp fluid to transfer it too.
As for the kind of applications we're talking about here, these claims of 100%+ efficiency are just a marketing and spec playing game to fool guys like Harry into thinking that one company's boiler is far better than anothers when they are in fact the same. That's why you find the claims in the marketing hype. When you read the actual spec sheet, as in the case of the one Harry provided, nothing indicates it's 100%+ efficient. Nor does it show up in any govt list of efficient boilers. Yet it has Harry convinced that the Britts are onto some true miracle.
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On Nov 25, 8:07am, snipped-for-privacy@optonline.net wrote:

Its like the Hydrogen Generators to increase gas milage, or magnets, air turbulators, fuel ionizers, electronic bug repellers, pipe magnetic delimers and the thousands of scams we get everyday. WC Fields said it best, "there is a sucker born every minute".
Actualy his refrenced boiler is at SEDBUK and has a top A class rating of 88.7%. Try the SEDBUK site search for Warmflow, the GS25A is second on the list. SEDBUK tries to do a real world test, their conservative results you should realise. I think their testing is more real world than US testing. But Warmflow has even better models Harry missed at Warmflows site and Sedbuk.
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On Thu, 25 Nov 2010 11:20:28 -0500, "Stormin Mormon"

Yeah, he didn't say it either.
http://www.historybuff.com/library/refbarnum.html
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.
I know the difference between gross and net either way your boiler still comes up way short . Gross, as in in a laboratory, thats a joke, you cant even show independant test results of that mythical number you preach. Your posted crap ass boiler is no better than 88% and you stated it over 100, show me a published number ov over 100%, and that unit isnt the best unit that company makes, thats another joke. You see harry its what you use and put out in home, in real world use that counts. You cant reach your mythical gross efficiency number in a house, so who cares You keep backtracking and denying the facts you post when I provide proof you are wrong, Your link showed us a boiler thats not 100% as you state, I show you SEDBUK rating, you deny they exist. Its their newest rating, you say ity must be old. You are lying to yourself
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om...
Bottom line You are a &%#)* *&*()&^ &*()#&?, you cant show us that 100% + fabrication you were suckered into purchasing.
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Since you want to use Wikipedia and I dont know how to paste look up Condensing boilers, you will find what I said is true that 98% is the highest claimed for Condensing boilers, but also that figure is optimistic, a bit high, and a reduction of 4-5% is more realistic or real world performance. That makes condensing boilers about 93% efficient Maximum.
By SEDBUK this gives Condensing boilers a typical seanonal efficiency of 82-89% HHV.
I quote Wikipedia
""When installed in real houses, the performance of condensing boilers is typicaly 4-5% lower than in laboratory tests by groups such as SEDBUK . This gives the typical seasonal efficiencies of 82-89% in the UK [ HHV ]. ""
This is your testing done by your SEDBUK, we in the US have the same ceritified Gav standardised testing and sind same results, end use results are less optimistic than advertised by manufacturers and probably put units condensing units around 90%, you just dont get more Btus out than you put in.
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