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HalfMooner
Dingaling
Philippines
15831 Posts |
 Posted - 08/11/2009 : 14:20:07 [Permalink]
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Originally posted by astropin
Originally posted by HalfMooner
I don't know about you guys, but I see a future for this amazing stuff. I'm going to hoard nitrogen. From here on, I'm keeping my apartment filled to the ceiling mostly with nitrogen.
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You're funny.
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You won't think I'm so damned funny when you run out of nitrogen. 
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“Biology is just physics that has begun to smell bad.” —HalfMooner
Here's a link to Moonscape News, and one to its Archive. |
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R.Wreck
SFN Regular
USA
1191 Posts |
Posted - 08/11/2009 : 15:37:44 [Permalink]
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| Here is an explanation of why compressed air contains moisture. Where I work we have large centrifugal compressors. They are equipped with coolers to condense the moisture out of the compressed air. Even with that the air receivers (large holding tanks) contain water in the bottom and must be periodically drained. It is a real phenomenon. |
The foundation of morality is to . . . give up pretending to believe that for which there is no evidence, and repeating unintelligible propositions about things beyond the possibliities of knowledge.
T. H. Huxley
The Cattle Prod of Enlightened Compassion
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vikingne
New Member
3 Posts |
Posted - 08/12/2009 : 18:16:42 [Permalink]
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"That's not an argument for pure nitrogen in the tyres, unless you can also prove that pure nitrogen keeps the tyre inflated longer than ordinary air."
Please see the Clemson Study at the link below. A scientic study conducted at a major University. Nitrogen works!! Or are you thinking there is some kind of a scam in the study, Maybe Clemson has a vested interest??
http://www.getnitrogen.org/savebillions/index.php
BINGO!!! |
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Dave W.
Info Junkie
USA
26021 Posts |
Posted - 08/12/2009 : 21:12:41 [Permalink]
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Originally posted by vikingne
Please see the Clemson Study at the link below. A scientic study conducted at a major University. Nitrogen works!! Or are you thinking there is some kind of a scam in the study, Maybe Clemson has a vested interest??
http://www.getnitrogen.org/savebillions/index.php
BINGO!!! |
Wow, not too unhappy with yourself, are you?
The problem with the Clemson study is that it was done on fleet trucks. Read it for yourself:The tables and plots presented in the report are calculated from data obtained from truck tires in static state and rolling resistance with variation of pressure was studied. The conclusions derived here can represent real condition in road testing with respect to pressure variation. All the results presented in the report are consistent with the objective. The biggest problem with that study are the basic numbers they derive. They say, the "leakage rate of air inflated tires is about 0.11 Kpa per week..." which is 0.015954 psi per week (1 psi = 6.894757 kPa), so it would have taken the air-filled tires 62 weeks to lose 1 psi. In other words, they would have us believe that these truck tires (logging an average of 2,500 miles per week) would go over 150,000 miles before losing 1 psi, which at the pressures they relate would be less than 2%.
That's for the air-filled tires, which is simply unbelievable. Either it's flat-out wrong, or truck tires simply don't lose air anywhere close to the rate that passenger cars do, otherwise air-inflated tires on passenger cars would maintain inflation to within the precision of measurement of the average tire-pressure guage longer than the life of the tire. I've never seen a tire-pressure guage graduated in milli-psi, have you?
Even worse is when we get to the nitty-gritty and see how the researchers were basing their claims. Table 8 is the prime culprit. They take the numbers in table 8 and claim that Nitrogen-filled tires have 70% less rolling resistance than air-filled tires, but that's not what they calculated at all. They took the difference in rolling resistance between the start and end of the tests, and found that the Nitrogen-filled tires had a 70% lower increase in rolling resistance. To call a 70% difference in increase in RR the same thing as a 70% difference in RR is astoundingly poor physics.
Made all the worse because if you just look at the raw data, you'll see that in two of the three test sites, the air-filled tires had lower rolling resistance throughout the entire test. In fact, if you look at the numbers closely, you'll see that the Nitrogen-filled tires had a linear-average rolling resistance of 29,627,797 N, while the air-filled tires had an average RR of only 29,297,971 N. That's right, the average RR of the air-filled tires was only 98.8% of the RR of the Nitrogen-filled tires. And since lower rolling resistance is why we're supposed to keep our tires at their proper inflation, table 8 makes it clear that we should fill truck tires with air, doesn't it?
Of course not. Table 8 also shows us that the researchers were damn sloppy. The air-filled tires all had a lower rolling resistance than the Nitrogen-filled tires because in two of the three test sites, the air-filled tires were all filled to a higher pressure than the Nitrogen-filled tires. The Nitrogen-filled tires were filled to an average of 5.8 kPa at the start of the test, while the air-filled tires were filled to 6.26 kPa, a difference of 7.3%. At the end of the tests, the Nitrogen-filled tires had an average pressure of 5.68 kPa, while the air-filled tires were at 5.84 kPa, favoring air-filled again, but only by 2.7%. And remember, the difference in pressure in the air-filled tires was an insanely small 6.4 one-hundredths of a psi. After a whole four weeks.
(Again: if car tires worked that way, it would take over 14 months to register a 1-psi drop in pressure, and nobody would be suggesting that everyone check every month.)
Do tires which are filled to a higher pressure lose that pressure faster than tires filled to a lower pressure? Seems like it would be intuitively true, but I don't know for sure. If it is true, then the test was set up in such a way as to ensure that the air-filled tires would perform worse than the Nitrogen-filled tires.
Everything in section 5.2.5.3, "Fuel Economy and Environmental Effects," is bogus because it all hinges upon the idea that Nitrogen-filled tires had 70% less RR, when in fact, in the tests, almost all of them had more rolling resistance, and so worse fuel economy, simply because the tires weren't filled to as large a pressure as the air-filled tires. The idea that "one can save about 67 gallons of diesel every week by using nitrogen inflated tires" (and thus save money and emit less CO2) is not just unsupported by the data in the Clemson study, it is contradicted by the data in that study. The conclusions in the study, based upon that 70% figure (which was probably just a mistake, but one which should have been caught and fixed in review), are entirely a crock.
Really, what the numbers tell us is that we should maintain our tire pressure well, with regular checks, regardless of what is inside the tires.
Plus, the Clemson test parameters were so extraordinarily outside the conditions found on an average passenger car (tires inflated to over 100 psi, running 2,500 miles per week, etc.) that they simply cannot be taken as evidence that any average car owner should switch to Nitrogen. The study doesn't even support the idea that truck fleet owners should switch, because of the wrong reasoning in it.
Got anything without such glaringly obvious errors in it, vikingne? Or was that "BINGO!!!" an indication that you had brought your "A" game? |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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Dave W.
Info Junkie
USA
26021 Posts |
Posted - 08/12/2009 : 21:46:21 [Permalink]
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Oh, and the Get Nitrogen Institute (GNI) is simply wrong to include the Clemson study under the heading "Vehicle Type: Passenger Car" ...and to claim it was a "Lab" study ...and to claim that it lasted five months ...and to claim that the study claimed 6% fuel savings ...and to claim that the study claimed 31% extended tire life ...and to claim that the study claimed a yearly savings of $149.83.
Really, there are so many things wrong about what the GNI says about the Clemson study that I would wonder if anything else they say is true. Reporting on what the study says should be a no-brainer, but they apparently get almost all of the details wrong. They keep a copy of the PDF file on their own servers, and link to it, fercryinoutloud! How could the GNI be so wrong about something they seemingly want people to read? They've simply shot their own credibility in its foot.
Edited to add that I decided to go ahead and check out the other studies listed at GNI's page (vikingne's link):
The Australian study to which GNI gave three stars? The link goes to an Australian tire dealer's Website, which lacks even a single mention of any scientific study. Under the "FAQs," you can find "So what's Nitrogen all about?" which also doesn't mention any research, and makes the bizarre claim that the "only by-product" in the process they use to create Nitrogen gas is Oxygen, which must mean that the water "and any other pollutants in the air" are magically disintegrated. Now that is something the world should know about! But GNI gets 0% for seemingly making a bunch of stuff up.
The University of Bologna study isn't even a study, it's a couple of theoretical calculations for a non-moving car with some reporting of studies from the 1960s thrown in, along with copy-and-pastes of tire companies' suggestions for using Nitrogen fill. The only number that GNI uses from it is the 48% reduction in pressure loss, but GNI wrongly claims that it includes "Field and Lab" work, which it flatly does not. Remarkably, GNI gives this entirely math-on-the-page report two stars, while at least Consumer Reports put a bunch of real tires outside for a while. GNI gets 50% correct, but loses points for obviously giving this piece more credit than it deserves.
Speaking of Consumer Reports, GNI links to its report, too, and gives it half a star. It is the only test that GNI reports accurately, but they clobber it for not doing the test under real-world conditions (as if U of Bologna did?!). GNI claims that if the tires had been supporting the weight of a car, the pressure loss would have soared from 3% to 24% over the year-long test, but they offer no support for that contention.
Overall, I would have to say that GNI is thoroughly not credible in its reporting of Nitrogen-fill studies. They clearly have an anti-air agenda, and a clear motive for pushing Nitrogen with obvious misrepresentations and other skullduggery. |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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HalfMooner
Dingaling
Philippines
15831 Posts |
Posted - 08/12/2009 : 22:01:30 [Permalink]
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Dammnit, Dave! You've ruined me financially. Now I have a whole apartment filled mostly with the stuff, and you've shown the world that it's probably worth no more than air!
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“Biology is just physics that has begun to smell bad.” —HalfMooner
Here's a link to Moonscape News, and one to its Archive. |
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Dave W.
Info Junkie
USA
26021 Posts |
Posted - 08/12/2009 : 23:30:21 [Permalink]
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Originally posted by HalfMooner
Dammnit, Dave! You've ruined me financially. Now I have a whole apartment filled mostly with the stuff, and you've shown the world that it's probably worth no more than air! |
Don't worry about it too much, Mooner, since there's plenty more of the stuff in your toilet which might one day power your scooter. |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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Dr. Mabuse
Septic Fiend
Sweden
9687 Posts |
Posted - 08/13/2009 : 05:47:57 [Permalink]
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Originally posted by R.Wreck
Here is an explanation of why compressed air contains moisture.
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What that website is saying is basically that relative humidity isn't dependent on over-all pressure, but the dew-point is absolute.
But they provide no reference to that effect.
I totally buy the fact that you can accumulate water in the tanks, but I suggest that this happens when the uncompressed air is warm and humid, and when the compressed air gets inside the pressure tank which is cooler the dew-point drops because of this lower temperature.
I maintain that the dew-point is dependent on the amount of molecules in the gas that can help keep the water solved. I could be wrong, and if I am, I'll gladly read your source because this is something I don't want to be wrong about. I take pride in my physics knowledge, since I got high grades in it when I went to school, but sometimes you forget stuff.
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Dr. Mabuse - "When the going gets tough, the tough get Duct-tape..."
Dr. Mabuse whisper.mp3
"Equivocation is not just a job, for a creationist it's a way of life..." Dr. Mabuse
Support American Troops in Iraq:
Send them unarmed civilians for target practice..
Collateralmurder. |
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R.Wreck
SFN Regular
USA
1191 Posts |
Posted - 08/14/2009 : 11:19:43 [Permalink]
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Originally posted by Dr. Mabuse
Originally posted by R.Wreck
Here is an explanation of why compressed air contains moisture.
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What that website is saying is basically that relative humidity isn't dependent on over-all pressure, but the dew-point is absolute.
But they provide no reference to that effect.
I totally buy the fact that you can accumulate water in the tanks, but I suggest that this happens when the uncompressed air is warm and humid, and when the compressed air gets inside the pressure tank which is cooler the dew-point drops because of this lower temperature.
I maintain that the dew-point is dependent on the amount of molecules in the gas that can help keep the water solved. I could be wrong, and if I am, I'll gladly read your source because this is something I don't want to be wrong about. I take pride in my physics knowledge, since I got high grades in it when I went to school, but sometimes you forget stuff.
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There will definitely be more moisture in the compressed air receivers if the intake air is hot and humid, but there is always some. And yes, it does cool and condense in the receiver. The point is that there will be some water in the compressed air you use to fill your tires (unless the air has been sent through an air dryer, but I've never seen that done at a tire shop). Therefore there will be some moisture in any tire filled with air. I haven't seen any evidence presented that shows that the amount of water likely to be in a tire shortens the tire's life. And I'm not suggesting that paying extra for nitrogen is worth it to eliminate the moisture. |
The foundation of morality is to . . . give up pretending to believe that for which there is no evidence, and repeating unintelligible propositions about things beyond the possibliities of knowledge.
T. H. Huxley
The Cattle Prod of Enlightened Compassion
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HalfMooner
Dingaling
Philippines
15831 Posts |
Posted - 08/14/2009 : 13:42:16 [Permalink]
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Water actually preserves latex, as demonstrated by latex offerings thrown into water pools by the Mayans. How this applies, if at all, to modern rubber tires, I don't know, but I do understand they contain little if any rubber from natural latex.
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“Biology is just physics that has begun to smell bad.” —HalfMooner
Here's a link to Moonscape News, and one to its Archive. |
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Lyndon
New Member
3 Posts |
Posted - 11/22/2011 : 15:23:49 [Permalink]
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I am a Distributor for NitroFill and an informed supporter of nitrogen tire inflation. Those that claim that free air is composed of 79% good nitrogen and 21% hurtful wet oxygen are correct. The key to nitrogen tire inflation is to effectively remove 80% of the wet oxygen content to achieve 95+% dry nitrogen purity in the tires, which does entail using rather expensive nitrogen generators to achieve. Many auto service shops charge around $20 to perform the conversion, plus free top-offs when you stop in - simply outrageous, right?!!
Various, reputable "scientific" studies support the benefits of nitrogen tire inflation. Studies prove that nitrogen tire inflation improves tire pressure retention and rolling resistance by 70%, thus significantly improving fuel economy and tire life. Go to NitroFill.com or getnitrogen.org to check it out. The Consumer Reports study is flawed; tires don't operate in ovens.
I believe that most of us, excluding stupid people, can agree that proper tire pressure maintenance will produce optimal fuel economy and tire life. However, around 80% of drivers do a poor job of doing so. Who relishes monthly tire maintenance, though you can save $20?!
TPMS sensor alarms, which must be annoying to many drivers using air inflation, don't go off until tires are deflated by 20%; at that point you may be reducing your fuel economy by as much as 10%! Moreover, the corroding affects of wet oxygen in your tires will eventually cause problems with TPMS, providing another reliable source of revenue for maintenance shops. Nitrogen is an inert gas, thus can't corrode anything it comes in contact with, including our lungs.
Last, but not least, with nitrogen, I can honestly state that I have experienced a 9% improvement in fuel economy with my 98' Wrangler since switching to nitrogen ten months ago, and my ride is far more enjoyable, dependable, safer.
You "snake oil" supporters can continue to bother with your "free" air program, lose hundreds of $/year in fuel and tire costs, and continue your mission to harm our environment by emitting more pollution and expending more tires. Hey, but you're saving $20 for eschewing the nitrogen service fee. This is a free country - your choice.
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bngbuck
SFN Addict
USA
2437 Posts |
Posted - 11/22/2011 : 16:35:25 [Permalink]
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| Based on the job you did on Viking, it sounds like this is your kind of guy to deal with, Dave |
| Edited by - bngbuck on 11/22/2011 16:38:37 |
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Dave W.
Info Junkie
USA
26021 Posts |
Posted - 11/22/2011 : 17:06:22 [Permalink]
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Originally posted by Lyndon
I am a Distributor for NitroFill and an informed supporter of nitrogen tire inflation. Those that claim that free air is composed of 79% good nitrogen and 21% hurtful wet oxygen are correct. |
How, exactly, does Oxygen become "wet?"| Various, reputable "scientific" studies support the benefits of nitrogen tire inflation. |
Putting "scientific" in quotes is downright scary.| Studies prove that nitrogen tire inflation improves tire pressure retention and rolling resistance by 70%, thus significantly improving fuel economy and tire life. |
Can you name or link to even one of these alleged studies? If you're thinking of the Clemson study, it was seriously flawed, as I detail above.| Go to NitroFill.com or getnitrogen.org to check it out. |
No, you support your own claims.| The Consumer Reports study is flawed; tires don't operate in ovens. |
The Consumer Reports study isn't the only study that shows that Nitrofill is bunk.| TPMS sensor alarms, which must be annoying to many drivers using air inflation, don't go off until tires are deflated by 20%; at that point you may be reducing your fuel economy by as much as 10% |
Since most people who've got TPMS will ignore tire maintenance until the light goes on, nitrofill will be responsible for people driving on underinflated tires for 70% more miles.
Now, I don't but the 70% claim anyway, but if it were true, people who depend on the TPMS going off will be doing much more harm to the environment than TPMS-dependent people with air-filled tires. Nitrofill doesn't magically make the TPMS sensor alarm at only 10% underinflation, does it?| Last, but not least, with nitrogen, I can honestly state that I have experienced a 9% improvement in fuel economy with my 98' Wrangler since switching to nitrogen ten months ago, and my ride is far more enjoyable, dependable, safer. |
Where's your data?
Of course, you could get a 100% increase in fuel economy by switching to a '98 Saturn. Put brand-new, air-filled tires on it, and your safety and dependability worries won't be with the tires, they'll be with the brakes, suspension and engine.| You "snake oil" supporters can continue to bother with your "free" air program, lose hundreds of $/year in fuel and tire costs, and continue your mission to harm our environment by emitting more pollution and expending more tires. Hey, but you're saving $20 for eschewing the nitrogen service fee. This is a free country - your choice. |
Come back, please, when you've got data and a decent argument. |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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sailingsoul
SFN Addict
2830 Posts |
Posted - 11/22/2011 : 19:23:08 [Permalink]
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| What a bunch of garbage. |
There are only two types of religious people, the deceivers and the deceived. SS |
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Lyndon
New Member
3 Posts |
Posted - 11/23/2011 : 14:04:36 [Permalink]
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| Dear Dave W. Have you tried nitrogen inflation in your tires? Can't spare the 20 bucks? And to claim that your data is more sound then Clemson University is idiotic. I suppose you contend that Bridgestone Tire are idiots; Jay Leno too! And to request my personal experience data is as absurd as you are. The vast majority of nitrogen tire users love the product. Go ahead, spend your $20 at McDonalds, then get a life! |
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Nitrofill your car tires
