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Richard,  At the risk of getting yet another angry
phone call from you at home, I just have to chime in
again on the phase-change discussion.  I appreciate
your passion for your product, it has some very good
features.   However, I disagree with the science you
are trying to use the market it.  I have no vested
interest in either product, my only interest is to see
the scientific data presented correctly.

First the from an experimental design stand point of
view the science fair project was very good.  She
included two variables; A) Supracore B) EquiPedic C)
Control Group no pad.  She also used three replicates,
testing each pad on three different horses.  25 horses
would have been more statistically significant but
under the circumstances three is quite reasonable.  If
provided with all the data I could run an analysis of
variance to establish the statistical significance of
the differences.

The science project also benefited from the real life
testing that I suspect is missed in your lab test. 
Reading the report she tried very hard to control as
many variables as possible.  They used a GPS to
measure speed and distance, they were tested on the
same day so ambient temperature should be reasonably
close.  They also took measurements over a long enough
period of time to a achieve a steady state between the
heat of the horse and the cooling heat capacity of the
pad.

My primary complaint about the marketing data
presented is it ignores heat capacity.  There isn't
enough heat capacity in the phase change material
contained in the pad to make a significant reduction
in temperature.  Assuming there is about 1 lb of phase
change material contained in the pad and the average
horse weights 1000lbs.  By way of analogy this would
be like dumping 10lbs of ice (another very inexpensive
phase change material, solid to liquid) into my
swimming pool in Texas in July and expect to measure a
significant drop in temperature.  Sure if I measure
the temperature right next to the ice just as I dump
it in I'll see a lower water temperature.  But after
15 mins when all the ice has melted and the water
circulation (blood circulation in the case of a horse)
has mixed the cool water with the warm water the
average temp of the pool will not have changed
significantly.  Also once melted the ice will not
spontaneously refreeze to repeat the cooling cycle. 
Same with your phase change material, it won't
refreeze until the pad is taken off the horse and
allowed to cool.  Most endurance riders ride for hours
rather than minutes and the phase change will be
melted long before you have time to refreeze it at a
hold.

In the case of the science project I suspect they
measured temperature over a long enough time period
that all the phase change material in the pad was
melted and other cooling mechanisms dominated. 
Evaporation (yet another phase change process, liquid
to gas) is a very efficient cooling mechanism.  The
horse carries gallons of available water in their
system that is easlily replenished to evaporate for
cooling.  Again, I suspect that the other pad and no
pad are more efficient at evaporate cooling.

Richard, In your Lab Test did you take into account
heat capacity?  If so how?  Did you factor into the
experiment the relative heat capacities of the horse
and pad?

Kathy, I sure hope your daughter received an A+ for
the project.  We have engineering college grads who
couldn't set up an experiment this well.  You need to
encourage her to follow a career in engineering or
science.  She has very sound logical thinking.

Best Regards, Pete

------------------------------------------------------

From: "Richard Sacks" <rsacks@xxxxxxxxxxxxx>
Subject: [RC]   EquiPedic Heat Comparisons

Kathy I am in no way dissing your daughter or the
efforts she made with 
=
her project. I do know where you live (Winton, CA),
which to us who 
live =
on the coast of CA is the Sierra foothills. As you
know I provided you 
=
daughter with materials for her project (including a
cross section of =
our pads). When I tried to discuss your daughter's
project with you in 
=
March to let her know about some variables she might
not have =
considered, you told me I was trying to stifle her
creative abilities. 
=
No need to be defensive. I am simply trying to point
out that there are 
=
many variables involved when testing for heat
dissipation beyond simply 
=
taking temperatures. There are other variables that
will affect results 
=
such as humidity, wind speed (wind chill factor),
caloric capacity of 
an =
individual horse, etc. Static testing at extreme
temperatures (higher 
or =
lower than normal) is used because they can be
indicative of "real 
life" =
results. Crash testing of cars is done on a limited
number of cars with 
=
dummies not live humans. I for one would not want the
car I purchase to 
=
have been crash tested and I certainly wouldn't
volunteer to be the =
crash test dummy. I would rather extrapolate from the
test results what 
=
the effect would be in "real life".

The testing done for us stands on it's own. It too is
what it is. It is 
=
simply a comparison of the effect of heat on a variety
of materials 
used =
in saddle pads. Although we expected our pads to
perform as they did, =
there were results that surprised us. One company that
changed their =
construction from bubble wrap to Styrofoam beads in an
attempt to allow 
=
for more cooling may also be surprised that their
newer pad was hotter 
=
than their old pad. We were also surprised to find
that pads using an =
open weave non slip bottom were actually hotter than a
pad that uses =
closed cell neoprene.

The interesting thing about this is that our testing
simply confirmed =
what other companies and government agencies found
when they did their 
=
own testing. Phase change material will stabilize the
surface =
temperature of a subject and make them feel more
comfortable. There are 
=
many ways to achieve cooling when using textiles. Many
riders have 
found =
this out when using Cool Medics evaporative cooling
products. I may 
want =
to use this type of approach on a very hot day but I
wouldn't want to =
use it on a cold day. The advantage of phase change
material is that it 
=
adapts to the environmental conditions and changes how
it attempts to =
regulate the individuals temperature based on those
conditions without 
=
outside intervention. This is what we wanted to bring
to the equine =
world. We felt that this approach should not be
limited to military and 
=
human athletic endeavors. We hope that we were able to
accomplish this 
=
and that those who have purchased our products are
satisfied with them.

Richard Sacks
rsacks@xxxxxxxxxxxxx
http://www.equipedic.com




               
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