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#1
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posted to rec.boats.cruising
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Jeff writes:
No one really cares about the Amps in a system where the load varies. So what. My point is, the spec sheet uses gibberish. "Amp-hours" are not a measure of "current". The author couldn't pass a freshman engineering class. If they can't even get that right, then the actual product must be a joke. A spec sheet for a heat pump ... that doesn't give the heat pumped? Yes, BTU/hour would have been handy. Handy? How about less than utterly ridiculous. yada yada yada - if this is the only real problem you can find what's the big deal? Phoney-baloney pseudo-technology marketing doesn't pass the crank test. It is a mad inventor's perpetual motion machine. Then perhaps you should learn some of that stuff. I posted one link to CO2 systems (out of thousands I found in a few minutes), here's another: http://www.appliancemagazine.com/ama...hp?article=567 Despite the cheerleading, the guy admits there are no commercial products based on CO2, and if there were, they would be less efficient and cost more. "... introducing new refrigerants is never easy." Right, because the old ones are far better. "... expect to see systems ...in the years ahead." Right. Just believe, even though no one has any idea how to build one. Reminds me of the zombies who preach Peltier devices. |
#2
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posted to rec.boats.cruising
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Richard J Kinch wrote:
Jeff writes: No one really cares about the Amps in a system where the load varies. So what. My point is, the spec sheet uses gibberish. "Amp-hours" are not a measure of "current". The author couldn't pass a freshman engineering class. If they can't even get that right, then the actual product must be a joke. It looks like you can't read - the spec sheet says "Average current consumption for 12 VDC systems over 24-hour period" I think we've found our new Jaxashby! A spec sheet for a heat pump ... that doesn't give the heat pumped? Yes, BTU/hour would have been handy. Handy? How about less than utterly ridiculous. yada yada yada - if this is the only real problem you can find what's the big deal? Phoney-baloney pseudo-technology marketing doesn't pass the crank test. It is a mad inventor's perpetual motion machine. Yes, I suppose you would be the "crank test." Frankly, the fact that you think its a hoax makes it look like its probably breakthrough technology and worth considering. I wonder if I can buy stock in the company! Then perhaps you should learn some of that stuff. I posted one link to CO2 systems (out of thousands I found in a few minutes), here's another: http://www.appliancemagazine.com/ama...hp?article=567 Despite the cheerleading, the guy admits there are no commercial products based on CO2, and if there were, they would be less efficient and cost more. No, he says that new technology will be required to make it as efficient - in fact he states that its possible to improve efficiency "to parity with fluorocarbon-based equipment while achieving the aforementioned environmental benefits described." And while there are no home air conditioners with CO2 yet, Coca-Cola deployed 1000 CO2 based vending machines at the last Olympics, CO2 Heat & A/C units are shipping in fleet vehicles, and the military uses it. Its a major advantage to have a system that can be opened, repaired or reconfigured, and recharged without expensive equipment or a license. And having only a few moving parts is also an advantage. This particular device might no be suitable for all, but its not inconceivable that this type of system will be the standard in a few years. "... introducing new refrigerants is never easy." Right, because the old ones are far better. Holy Back Pedal Batman! First you claim they're impossible, now you're claiming they're just not quite as good! Which is it? And you must realize that CO2 was one of the "old refrigerants" that got replaced by fluorocarbons that were perceived as better. "... expect to see systems ...in the years ahead." Right. Just believe, even though no one has any idea how to build one. Right, that's why there are thousands in use now. Reminds me of the zombies who preach Peltier devices. Peltier technology certainly works and has it place. Are you claiming that's a hoax also? |
#3
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posted to rec.boats.cruising
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Jeff writes:
It looks like you can't read - the spec sheet says "Average current consumption for 12 VDC systems over 24-hour period" I explained why the spec you quote is stupid, because current is not measured in amp-hours. You haven't grasped that. Peltier technology certainly works and has it place. Are you claiming that's a hoax also? It was touted for many applications that an engineer could easily see were futile. To the extent it was promoted to the public that couldn't so easily see the futility, yes, it was a hoax. Yes, CO2 is a refrigerant and you can build a refrigerator based on it. What you can't do is build a CO2 refrigerator that works as well as, say, an R-134a unit. If you were to genuinely engineer improvements in CO2 refrigeration that made it less ridiculous, then those same improvements would make R-134a systems that much better, too. This is because R-134a is an inherently better phase-change refrigerant in all its material properties than CO2. It's like the banned R-12 vs R-134a. R-12 is always the better choice, in terms of engineering. The substitution was made for reasons other than engineering. To the extent CO2 is used, it is essentially the same process, substituting an inferior refrigerant for political reasons, not because it is anywhere as good as what it replaced. You can make a phase-change heat pump out of any condensible gas. Few such materials make a good heat pump. |
#4
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posted to rec.boats.cruising
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If you look closer at the technology you will find that the working
fluid is helium. In a Stirling machine this is an excellent choice. The CO2 is only in a secondary circuit to transport heat from the refrigerated area to the Stirling cooler and is not used in the stirlig engine itself.. "RJK" == Richard J Kinch writes: RJK Jeff writes: It looks like you can't read - the spec sheet says "Average current consumption for 12 VDC systems over 24-hour period" RJK I explained why the spec you quote is stupid, because current is not RJK measured in amp-hours. You haven't grasped that. Peltier technology certainly works and has it place. Are you claiming that's a hoax also? RJK It was touted for many applications that an engineer could easily see RJK were futile. To the extent it was promoted to the public that couldn't RJK so easily see the futility, yes, it was a hoax. RJK Yes, CO2 is a refrigerant and you can build a refrigerator based on it. RJK What you can't do is build a CO2 refrigerator that works as well as, RJK say, an R-134a unit. If you were to genuinely engineer improvements in RJK CO2 refrigeration that made it less ridiculous, then those same RJK improvements would make R-134a systems that much better, too. This is RJK because R-134a is an inherently better phase-change refrigerant in all RJK its material properties than CO2. RJK It's like the banned R-12 vs R-134a. R-12 is always the better choice, RJK in terms of engineering. The substitution was made for reasons other RJK than engineering. To the extent CO2 is used, it is essentially the same RJK process, substituting an inferior refrigerant for political reasons, not RJK because it is anywhere as good as what it replaced. RJK You can make a phase-change heat pump out of any condensible gas. Few RJK such materials make a good heat pump. -- C++: The power, elegance and simplicity of a hand grenade. |
#5
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posted to rec.boats.cruising
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Ole-Hjalmar Kristensen writes:
If you look closer at the technology you will find that the working fluid is helium. That's rather obscurely and incompletely explained on the Web site, being that purveyors of perpetual motion cannot, of necessity, be too specific about how it is achieved. But if you're correct about the helium and Stirling, then so much the more is this made not credible. |
#6
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posted to rec.boats.cruising
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Hmmm. I actually find the following explanation a pretty good
description of the principle, if we assume the reader knows the Stirling cycle. I cannot comment on the suitability of CO2 in the secondary circuit, but it seems clear that the primary circuit is a Sirling engine with helium as a working medium, and that the CO2 is used to transport heat from the refigerated area to the Stirling engine. http://www.avxcel.com/free_piston_stirling_cooler.html http://www.avxcel.com/heat_rejection.html http://www.avxcel.com/marine_refrigeration.html "RJK" == Richard J Kinch writes: RJK Ole-Hjalmar Kristensen writes: If you look closer at the technology you will find that the working fluid is helium. RJK That's rather obscurely and incompletely explained on the Web site, being RJK that purveyors of perpetual motion cannot, of necessity, be too specific RJK about how it is achieved. RJK But if you're correct about the helium and Stirling, then so much the more RJK is this made not credible. RJK -- C++: The power, elegance and simplicity of a hand grenade. |
#7
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posted to rec.boats.cruising
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Richard J Kinch wrote:
It looks like you can't read - the spec sheet says "Average current consumption for 12 VDC systems over 24-hour period" I explained why the spec you quote is stupid, because current is not measured in amp-hours. You haven't grasped that. But the spec sheet says "Average current consumption for 12 VDC systems over 24-hour period." This is the number of interest to most boaters, and the proper measure is Amp-Hours. You haven't grasped that. Condemning a product because the spec sheet isn't in exactly the terms you want to see is pretty petty. Peltier technology certainly works and has it place. Are you claiming that's a hoax also? It was touted for many applications that an engineer could easily see were futile. To the extent it was promoted to the public that couldn't so easily see the futility, yes, it was a hoax. Anything you say, Jaxie. Whatever is new and different must be a hoax. Yes, CO2 is a refrigerant and you can build a refrigerator based on it. What you can't do is build a CO2 refrigerator that works as well as, say, an R-134a unit. If you were to genuinely engineer improvements in CO2 refrigeration that made it less ridiculous, then those same improvements would make R-134a systems that much better, too. This is because R-134a is an inherently better phase-change refrigerant in all its material properties than CO2. The engineering issues are different - that should be pretty obvious to you, if you know anything about refrigerants. It's like the banned R-12 vs R-134a. R-12 is always the better choice, in terms of engineering. The substitution was made for reasons other than engineering. To the extent CO2 is used, it is essentially the same process, substituting an inferior refrigerant for political reasons, not because it is anywhere as good as what it replaced. So now we get to your central issue. You're defining the ozone-depletion and other environmental issues as simply "political" and somehow not relevant to the discussion. While R-134a is safer than other refrigerants it is still illegal to vent and difficult to handle properly. Its toxic and corrosive, and anyone who has had a larger refrigeration system serviced understands from the amount of gear the technician hauled down to the boat that these are not trivial procedures. A CO2 system, on the other hand, can be vented freely, and recharged with a simple cartridge. No license or special training is required. If this does not look like a significant advantage to you, then you should not be posting in a "cruising" forum. You can make a phase-change heat pump out of any condensible gas. Few such materials make a good heat pump. But you didn't base your argument on weighing pros and cons, you claimed that CO2 refrigeration was impossible, a hoax, and likened it to "perpetual motion machines." Thank you for admitting you were wrong, however obliquely. |
#8
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posted to rec.boats.cruising
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Jeff writes:
But the spec sheet says "Average current consumption for 12 VDC systems over 24-hour period." This is the number of interest to most boaters, and the proper measure is Amp-Hours. No it isn't. Current is measured in amps. Amp-hours are not a measure of current. Nothing could be simpler, and nothing more can really be debated about it. This is not an oversight, it shows the author is a fraud or a fool. While R-134a is safer than other refrigerants it is still illegal to vent and difficult to handle properly. Its toxic and corrosive, and anyone who has had a larger refrigeration system serviced understands from the amount of gear the technician hauled down to the boat that these are not trivial procedures. A CO2 system, on the other hand, can be vented freely, and recharged with a simple cartridge. No license or special training is required. If this does not look like a significant advantage to you, then you should not be posting in a "cruising" forum. You are in your typical error about the "simple cartridge" as a comparative advantage. A cartridge for CO2 at 1000 psi is not "simple" in comparison to ordinary refrigerants at 100 psi. Whatever "simplicity" advantage you are imagining, it inheres more in the usual refrigerants. The fact that it is *harder* to store CO2 in a cartridge, yet this is claimed as an "advantage", just further shows the stupidity and/or deceit of the claims. "Vented freely" is a political, not a technical advantage. CO2 is lousy refrigerant for all but a few unusual applications, because of its material properties, such as high saturation pressure, and low critical temperature. It does not fit ordinary refrigeration applications, and it cannot be engineered to do so. It only "works" as a political force-fit, like when Coca-Cola wants PR for the Athens Olympics. But you didn't base your argument on weighing pros and cons, you claimed that CO2 refrigeration was impossible, a hoax, and likened it to "perpetual motion machines." Thank you for admitting you were wrong, however obliquely. No, I said that this "tropikool" gadget amounts to perpetual motion claims, and that CO2 efficiency was a hoax, that efficiency (relative to, say, R-134a) was impossible. That politicians let you vent CO2 but not R-134a says nothing about their respective material properties as a refrigerant. I never said CO2 refrigeration was impossible in principle, just impossible that it would be practical in ordinary applications. You might as well claim that a steam engine is better than gasoline internal combustion, because we can fuel it with grass clippings instead of that expensive petroleum. Yes, it is possible to get steam power from grass clippings, but it is impossible that it could work better than a gasoline engine. Now I will admit I was wrong, in that if a politician holds a gun to my head and insists that CO2 is all you seem to be claiming, then yes, CO2 is just great. Since we still haven't reached quite that point, I regret I must maintain that the OP points to a product that is a phony based on either fraud or foolishness. |
#9
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posted to rec.boats.cruising
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Richard J Kinch wrote:
Jeff writes: But the spec sheet says "Average current consumption for 12 VDC systems over 24-hour period." This is the number of interest to most boaters, and the proper measure is Amp-Hours. No it isn't. Current is measured in amps. Amp-hours are not a measure of current. Nothing could be simpler, and nothing more can really be debated about it. This is not an oversight, it shows the author is a fraud or a fool. Yes current is measured in amps. But to be useful you need another measurement, time. That gives amp hours. Battery capacity is rated in amp hours, usually at a 20 amp rate. If I want to know what size batteries I need to supply my house load I measure the current used by each device, i.e. lights, fans, reffer, etc and determine the approximate time used by each device and compute total amp hours load over a 12 or 24 hour period. Multiply the amp hour load by two and use that size battery. So while you are correct that the measurement of current is amps, if a manufacturer list a spec of 54 amp hours usage in 24 hours it tells me a lot more than just 4 amps compressor draw. krj While R-134a is safer than other refrigerants it is still illegal to vent and difficult to handle properly. Its toxic and corrosive, and anyone who has had a larger refrigeration system serviced understands from the amount of gear the technician hauled down to the boat that these are not trivial procedures. A CO2 system, on the other hand, can be vented freely, and recharged with a simple cartridge. No license or special training is required. If this does not look like a significant advantage to you, then you should not be posting in a "cruising" forum. You are in your typical error about the "simple cartridge" as a comparative advantage. A cartridge for CO2 at 1000 psi is not "simple" in comparison to ordinary refrigerants at 100 psi. Whatever "simplicity" advantage you are imagining, it inheres more in the usual refrigerants. The fact that it is *harder* to store CO2 in a cartridge, yet this is claimed as an "advantage", just further shows the stupidity and/or deceit of the claims. "Vented freely" is a political, not a technical advantage. CO2 is lousy refrigerant for all but a few unusual applications, because of its material properties, such as high saturation pressure, and low critical temperature. It does not fit ordinary refrigeration applications, and it cannot be engineered to do so. It only "works" as a political force-fit, like when Coca-Cola wants PR for the Athens Olympics. But you didn't base your argument on weighing pros and cons, you claimed that CO2 refrigeration was impossible, a hoax, and likened it to "perpetual motion machines." Thank you for admitting you were wrong, however obliquely. No, I said that this "tropikool" gadget amounts to perpetual motion claims, and that CO2 efficiency was a hoax, that efficiency (relative to, say, R-134a) was impossible. That politicians let you vent CO2 but not R-134a says nothing about their respective material properties as a refrigerant. I never said CO2 refrigeration was impossible in principle, just impossible that it would be practical in ordinary applications. You might as well claim that a steam engine is better than gasoline internal combustion, because we can fuel it with grass clippings instead of that expensive petroleum. Yes, it is possible to get steam power from grass clippings, but it is impossible that it could work better than a gasoline engine. Now I will admit I was wrong, in that if a politician holds a gun to my head and insists that CO2 is all you seem to be claiming, then yes, CO2 is just great. Since we still haven't reached quite that point, I regret I must maintain that the OP points to a product that is a phony based on either fraud or foolishness. |
#10
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posted to rec.boats.cruising
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Richard J Kinch wrote:
Jeff writes: But the spec sheet says "Average current consumption for 12 VDC systems over 24-hour period." This is the number of interest to most boaters, and the proper measure is Amp-Hours. No it isn't. Current is measured in amps. Amp-hours are not a measure of current. Nothing could be simpler, and nothing more can really be debated about it. This is not an oversight, it shows the author is a fraud or a fool. Yes current is measured in amps. But to be useful you need another measurement, time. That gives amp hours. Battery capacity is rated in amp hours, usually at a 20 amp rate. If I want to know what size batteries I need to supply my house load I measure the current used by each device, i.e. lights, fans, reffer, etc and determine the approximate time used by each device and compute total amp hours load over a 12 or 24 hour period. Multiply the amp hour load by two and use that size battery. So while you are correct that the measurement of current is amps, if a manufacturer list a spec of 54 amp hours usage in 24 hours it tells me a lot more than just 4 amps compressor draw. krj Ya know, this thread keeps gettin sillier and sillier. Amp-hours, if anyone cares to look it up instead of just flappin, is a measurement of current. And I defy anyone, including Mr. Kinch, to find a way for current to flow without time. If current was without time, it could not possibly *be* current. It would then be reduced to "...potential for current to flow, which when flowing would be measured in amp-hours..." Current is a verb, it defines an action. Without the action, there's no flow. Without the flow there's no "amps", which is always measured against a unit of time - the convention being hours (notice I said 'convention'- you could use any time measurement, days, U-seconds, etc.). It cannot be measured without time - ever. Therefore, "amps" by itself, does not describe anything. You could say there is a measurement of an *instantaneous current* but that would still be just a snapshot of the presently measured current-against-time. Amp-hours is and has been the correct term because a "1 amp" device is defined by convention as a device that passes a current of 1 amp during the course of an hour. The term "1 amp" is simply a contraction for "device that passes 1 amp of current during the period of one hour" Now, isn't that a mouthful? Jeesh! The engineers and tech's of old used to actually *say* "amp-hours" when describing current, and all my old electronics textbooks use that term exclusively. So if Mr. Kinch wants to call all my electronics professors frauds or fools, so be it. But then I'll challenge him to come over and put his instruments where his mouth is and show us all how he manages to measure "amps" without time for the electrons to flow. Or was that holes flowing... hmmm... ![]() |