[s-cars] Re: Air to Water intercoolers

[mlp qwest]

Mark - I don't think I'm disagreeing with you.  From what I've seen of the
charge (intake) air to water heat exchangers, they generally seem, at least
the photos do, to be much more compact than equivalent air to air units.
It's one of the air to water units potential packaging advantages.  On the
other hand, the charge air exchanger is only one of the two heat exchangers
that an air to water system needs.  It looks to me like the individual air
to water cores can be extremely efficient, but you have to use two of them
in the air to water systems - Don't I get to argue that, to a certain
extent, you have to add the efficiency losses across both heat exchanges
together?  Second, for the most part (at least within the air to air FMIC
that have been done to date), well the heat exchange area's are huge, even
in comparison to the stock air to air unit.

OTOH, from what little I know about the process, at least as important, if
not perhaps more so, are comparing pressure, or?  pumping losses, along with
the extent of the temperature drop across the charge air heat exchange
system.  I think one gets to ignore the pressure loss across the 2nd
external radiator in the air to water setups, but pressure loss across the
charge air heat exchanger, whether in an air to air or air to water system,
I would guess could be compared on a 1:1 basis, with the advantage going to
the system with the least restriction or pressure loss?  Depending on the
designs used, its my impression that some of the air to water exchangers
feel they often have an advantage on pressure loss vs. some of the really
"efficient" air to air units, e.g. the long 24", thickly internally
"turbulated" side to side runs on units like Hap's and my and a few others,
like Brian Bilotti and Josh Moody's FMIC adaptations.  I guess the claim is,
they can offer more heat transfer capacity in a small "run" for less
drag/pumping loss.  Unfortunately my amateur attempts to get some "real"
measured pressure loss number for the stock IC came to naught.  Couldn't get
the manometer to provide a differential pressure reading for some reason.

Heck, let's have some one build & install an air to water unit on their car
and report the results.

Mike


~-----Original Message-----
~From: Mark Strangways [mailto:strangconst at rogers.com]

~
~Mike I have to disagree on the air to water being LESS efficient
~than air to
~air.
~I can get a much closer ratio of water in to air out temperatures than is
~possible with air to air exchangers.
~Water has a higher moisture content than air does (obviously) and
~essentially than is all that is heating up...
~There really is very little latent energy in dry air.
~
~I cannot write very good explanations with out many drafts so I hope this
~makes sense.
~
~If you had to remove as much heat using air to air methods in your fridge,
~the surface area's of the heat exchangers would be huge.
~I can get a 100,000 BTU hydronic coil (hydronic is the term for hot water
~heating) and put it into a relatively small (sq.ft) air stream. I can get
~air temperatures fairly close to the exiting water temp while passing 1000
~CFM over it.
~
~Mark S
~
~