IIRC when Slurry Guy was doing R tests, he made hollow cylinders of pc that he filled with a specific weight of ice at a specific temperature, closed them up with pc plugs, and then measured the amount of time it took for the ice to melt. With that information he was able to calculate the R factor. SG hasn't been around much lately so I can't ask him for details. He was the one who started the claim that compressed pc has a higher R factor than non-compressed.
spaceman
Ron Richter wrote:
Since most of us are waiting for warmer weather to arrive to begin PC activities again, I also, am casting about for projects. I teach school (science) in a rural high school in Alaska. Even here the Science Fair looms on the horizon and so casting about for a project that has lots of science and math in it led me to look into the R value question.
Seems mostly the R value is the inverse of the conductivity of the sample being tested. What I have gleaned from my readings so far is that there are a couple of places that do these tests according to ASTM standards and that these "standards" change for almost every type of material tested. Sending hundreds of samples to Oakland National Testing Laboratory is not even feasible.
I have plenty of time and control over the process of making the samples. Can anyone tell us of a simple way to test the samples? Maybe what we get is a time differential for thermal transfer and not the actual R Value, but it could answer the question regarding compaction and what happens. I would love to know that when we say the R value may be higher in a compressed block than loose dried PC we are telling the truth and not guessing.
Any thoughts?
Ron
No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.432 / Virus Database: 270.14.140/2621 - Release Date: 01/14/10 12:39:00
__._,_.___
