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Propylene glycol



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 It's my contention that since pure water has a lower specific heat (delta H, IIRC), it has a greater cooling capacity in that it can _exchange_ heat faster that a medium with a higher specific heat (e.g., EtGlycol or PGlycol) - also provided it has an outlet to exchange that heat to. However, since water has a somewhat low boiling point, the glycols offer a better advantage from the standpoint in that they don't either heat or cool in such a rapid manner. They can absorb more heat and act as a sort of "heat buffer" (any of you familiar  with pH and titration know what I'm talking about) because the typical cooling system or average VW is not efficient enough to exchange the required amount of joules to keep pure water from boiling/vaporizing/overpressuring/superheating your cooling system.
Did that make sense? I've had a couple of beers...
Oh well - I'm off to the Digest. I'll be getting hitched on Saturday and off in Jamaica until the 15th.
have fun everyone!  Jeff
  Larry <rocco16v@netzero.com> wrote: I've heard (can't remember where) that pure water has better cooling characteristics than any antifreeze, even though the AF has a higher ultimate boiling point.  The higher the ratio of AF to water, the worse the cooling.  Can't say for sure if this is true, since I've not experimented along these lines...take it for what it's worth (maybe nothing) Larry ----- Original Message ----- From: DEMETRIS RAPTIS To: scirocco-l@scirocco.org Sent: Wednesday, June 26, 2002 12:42 AMSubject: Propylene glycol
I noticed something peculiar the other day. It' been very hot lately around 90-93F. i was driving my 16V and I noticed that it was running cooler than usual around 80-83C water temp and oil temp at 95C steady!! I figured it will be a loose ground so I poped the hood . Grounds were fine , but coolant was leaking from the sensor on top of the plastic coolant reservoir. I fixed the seal temporary so the system holds pressure and gave it another ride. It ran at normal temps abit warmer than earlier.Now, everybody knows propylene glycol (Sierra) has better thermal conductivity and higher boiling point than ethylene glycol. What if I run 100% Sierra in a pressurized system?in theory it should run cooler. Mecca cooling systems claims so.Any input?Demetri


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<P> It's my contention that since pure water has a lower specific heat (delta H, IIRC), it has a greater cooling capacity in that it can _exchange_ heat faster that a medium with a higher specific heat (e.g., EtGlycol or PGlycol) - also provided it has an outlet to exchange that heat to. However, since water has a somewhat low boiling point, the glycols offer a better advantage from the standpoint in that they don't either heat or cool in such a rapid manner. They can absorb more heat and act as a sort of "heat buffer" (any of you familiar&nbsp; with pH and titration know what I'm talking about) because the typical cooling system or average VW is not efficient enough to exchange the required amount of joules to keep pure water from boiling/vaporizing/overpressuring/superheating your cooling system.
<P>Did that make sense? I've had a couple of beers...
<P>Oh well - I'm off to the Digest. I'll be getting hitched on Saturday and off in Jamaica until the 15th.
<P>have fun everyone!&nbsp; Jeff
<P>&nbsp; <B><I>Larry &lt;rocco16v@netzero.com&gt;</I></B> wrote: 
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<DIV><FONT face=Arial size=2>I've heard (can't remember where) that pure water has better cooling characteristics than any antifreeze, even though the AF has a higher ultimate boiling point.&nbsp; The higher the ratio of AF to water, the worse the cooling.&nbsp; </FONT></DIV>
<DIV><FONT face=Arial size=2>Can't say for sure if this is true, since I've not experimented along these lines...</FONT></DIV>
<DIV><FONT face=Arial size=2>take it for what it's worth (maybe nothing)</FONT></DIV>
<DIV>&nbsp;</DIV>
<DIV><FONT face=Arial size=2>Larry </FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B> <A title=raver@prodigy.net href="mailto:raver@prodigy.net";>DEMETRIS RAPTIS</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=scirocco-l@scirocco.org href="mailto:scirocco-l@scirocco.org";>scirocco-l@scirocco.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Wednesday, June 26, 2002 12:42 AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Propylene glycol</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>I noticed something peculiar the other day. It' been very hot lately around 90-93F. i was driving my 16V and I noticed that it was running cooler than usual around 80-83C water temp and oil temp at 95C steady!! I figured it will be a loose ground so I poped the hood . Grounds were fine , but coolant was leaking from the sensor on top of the plastic coolant reservoir. I fixed the seal temporary so the system holds pressure and gave it another ride. It ran at normal temps abit warmer than earlier.</FONT></DIV>
<DIV><FONT face=Arial size=2>Now, everybody knows propylene glycol (Sierra) has better thermal conductivity and higher boiling point than ethylene glycol. What if I run 100% Sierra in a pressurized system?</FONT></DIV>
<DIV><FONT face=Arial size=2>in theory it should run cooler. Mecca cooling systems claims so.</FONT></DIV>
<DIV><FONT face=Arial size=2>Any input?</FONT></DIV>
<DIV><FONT face=Arial size=2>Demetri</FONT></DIV></BLOCKQUOTE></BLOCKQUOTE><p><br><hr size=1><b>Do You Yahoo!?</b><br>
<a href="http://rd.yahoo.com/welcome/*http://fifaworldcup.yahoo.com/fc/en/spl";>Sign-up for Video Highlights</a> of 2002 FIFA World Cup
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