Re: Water Wetter

["Brant M. Miller" <brant@xxxxxxxxxxxxxx>]

Steve -

If a cooling system is functioning normally and the heat load is not
excessive, the coolant temperature is regulated by the thermostat.  When
the system is functioning poorly or the heat load is excessive, the
thermostat goes full open and the temperature of the coolant becomes a
function of coolant circulation rate, air flow rate thru the radiator, ai=
r
temperature, heat load (how hard the engine is working), and heat transfe=
r
coefficients.  Heat transfer coefficients are a function of a bunch of
things.

I've heard it said that Water Wetter permits the water to get into the
little pores of the engine casting, thereby improving heat transfer.  If
true, that would suggest that WW reduces the surface tension of the
coolant.  But looking at classical equations for heat transfer
coefficients, surface tension is not a variable.  That is, at least McAda=
ms
(Heat Transmission, McGraw-Hill) does not believe that surface tension
affects the heat transfer coefficient for heating and cooling inside tube=
s
- - which is an approximation of the automotive environment.  So if WW is a=

surfactant, I would not expect it to be effective at lowering coolant
temperature.

But those same equations do show that viscosity has an effect on heat
transfer coefficient.  So if Water Wetter is actually a viscosity reducer=
,
one would expect it to improve heat transfer.  "Wetter" sounds better tha=
t
"Slippryfier" or whatever, so maybe it is a viscosity reducer.

Whatever the science, quite a few Digesters have said that under tough
conditions, Water Wetter has improved their cooling system's performance =
- -
has lowered the temperature from abnormally high to about normal.  Of
course, Water Wetter can not lower the temperature below normal, as the
thermostat would simply close a bit to offset any improvement in heat
transfer coefficient.

Brant

Message text written by INTERNET:bmw@domain.elided
>Date: Tue, 26 Jan 1999 15:26:07 -0800
From: Steve Albrecht <albrecht@domain.elided>
Subject: Redline Water Wetter

I am confused by the marketing hype of Redline's Water Wetter.  The
label claims that it will lower the temperature of the cooling system
water by some amount, 10 degrees or something, I don't have a Water
Wetter container handy so I am working from memory (poor as that may
be).  Can someone with some chemistry background explain how this
works?  My understanding of the automobile cooling system is that the
coolant temperature is controlled by the mechanical/thermal properties
of the thermostat, not the chemical properties of the liquid coolant. =

So is this stuff snake oil or what? =


Thanks
Steve Albrecht
Golden Gate Chapter
'95 540 (still w/factory installed mud flaps)
German Shepherd (near 10 years old w/high mileage & worn left rear
suspension)
Gray Cheek Parakeet (reincarnation of a Mafia hit man - also 10 years
old)<

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