The condensing boilers were designed to recycle the CO2 emissions and steam that would normally be vented outside and then feed it back into the system through the waste water pipe. The new system was touted to increase efficiency by as much as 93%.
First of all, I believe the author should have said that it will increase the efficiency to 93%, not by 93%. The traditional non-condensing boiler probably operates around 75% efficiency, based on HHV of the fuel.
But my question is not about the efficiency increase. Rather, it concerns the CO2. From what the author says, the CO2 leaves in the waste water, and that is recycled back into the system. For one thing, although some of the CO2 would dissolve in the water, I believe that a considerable portion of it would end up in the flue gas. There is no way to eliminate the flue gas entirely, since most of it is nitrogen which entered with the combustion air. So, implying that all of the CO2 is removed by condensing the water in the flue gas seems deceptive to me.
Additionally, I feel certain that the acidic water condensed from the flue gas would not be recycled into the system. You certainly wouldn't want the dissolved CO2 and H2S going into your boiler. Rather, the wastewater must be dumped somewhere. And neutralized, if your disposal pipe is not made of a material which can tolerate the low pH of the water. Is this not correct?
Now, for the global warming bunch, who justify these boilers partly by this claim of CO2 removal:
1) As I stated above, I don't think it is possible to remove all of the CO2 by condensing the water in the flue gas.
2) Any CO2 which is dissolved in the condensed water in the flue gas, if it doesn't react with an alkaline chemical to form carbonates, will eventually end up in the oceans or the atmosphere. So, it's sort of like sweeping it (the CO2) under a rug and pretending you've eliminated it, when in fact, it comes back to us from another direction.
Do you agree with these points, or am I missing something? Again, I don't doubt the improved efficiency, but this CO2 removal business just sticks in my craw.
first of all, the author of the article is a MORON.
ignore the idiot.
condensing boilers get efficiency ratings similar to high efficiency furnaces...maybe just a schmidge higher...but not enough to brag about. that means 93 to 99 percent efficient. btw, these efficiency ratings are bullshit. they are assigned by a government agency just as automobile mpg figures are assigned. you will get something similar to what they say but just because one car is assigned 40mpg and another is assigned 42mpg does not mean you are guaranteed that. very likely the lower rated vehicle will get better mileage than the higher rated vehicle.
a traditional non condensing boiler (assuming is is hot water not steam) can get up to 82 or 86 percent efficient. sometimes even higher I think, but I don’t know for sure off the top of my head and I don’t want to do research for this post for a point or three efficiency to prove a point.
CO2 is a hoax. forget about that crap. You save CO2 emissions by burning less fuel. Period. any claims that some of the co2 emissions are trapped in the water vapor of the exhaust are cause to point at the idiot and laugh. no further comment from me.
when they say “recycled back into the system”, they lie. nothing in the exhaust stream is recycled back into the system. if there is an economizer(technical term in a steam boiler system) there is heat recycled back into the system through a heat exchanger but that is all, and this article is about hot water condensing boilers, not about steam systems with economizers installed. so ignore this idiot writer. The only way they get away with “recycled back into the system” ccomment is that the water vapor in the exhaust stream is turned into water and it trickles back to the boiler combustion chamber where it sits when the boiler is unfired(not running) and gives up its heat to the boiler heat exchanger. when enough of this water has accumulated in the combustion chamber, it flows out the overflow to the floor drain next to your boiler. but any efficiency gains from this trickle effect are marginal at best in my opinion. the efficiency gains are simply from the fact that the exhaust exiting your house is a lower temp than that from a non-condensing boiler.
You aint no dummy. the co2 removal claims should stick in your craw. it is pure horshit. The only possible claim of a benefit is reduced acid rain since a portion of the acidic properties of combustion are sent to your sewage treatment plant to be dealt with there rather than to your clouds in the sky to produce acid rain. btw, the “bugs” at your local sewage treatment plant produce CO2 as well. so does poop and landfills and compost piles.
If you want to learn a little more bout the ecosystem, google biological oxygen demand...or BOD for short.
any more questions, don’t hesitate to ask. If I don’t know, i’ll say so. one thing I guarantee is you will know exactly my opinion on the matter when I answer. I don’t play games or fuss with diplomacy.
ok, after re reading my comments, I must modify some part of it. there are rare instances when an economizer is part of a hot water boiler system. This economizer may in fact have it’s own condensate drainage system. this may be what the author is talking about when he talks about a drain pipe freezing. if the drain pipe is at an economizer near the outdoors and thus subjected to outside temps it could in fact freeze.
Upon further thought, I think this is what this article is about. I could see a design in which the condensing portion of the boiler system is restricted to the economizer only and thus a manufacturing savings could be realized in the boiler heat exchanger itself by NOT constructing the boiler out of stainless. the rationale for this would be that the boiler is not a condensing boiler, the economizer is only the condensing portion. I personally have never seen nor heard of such a design, but it makes sense to me that someone somewhere might have thought of this hair-brained concept and produced a product. Now I’m beginning to understand why there is a problem with the condensate drain freezing up and plugging up the whole dam boiler system.
BAD DESIGN.
condensing boilers are not a bad concept however.
ps this revelation also would explain why the author is usting the phrase “recycled back into the system”. economizers do recycle heat back into the system.