graphed data comparisons (cont.)
Thermal Differential: The Thermal Differential is the overall rating of the substance based upon the Thermal Capacity and the Thermal Conductivity of a substance. When it's all said and done, this is the chart/number that has to be looked at when putting the whole schebang together. This is the sum of a substances total effectiveness as a cooling medium (minus viscosity that is)
(the higher the better)
(higher the better)
This is the Dynamic Viscosity ratings of these liquids. Dynamic Viscosity is the measure of resistance of liquid in a tube or capillary. It's measured by pouring liquid in one end of a tube and measuring how quickly it reaches the other end. It is represented in Poise. The industrial standard uses Centipoise (cP). 1 Centipoise = .01 Poise.
the lower the number = the thinner the liquid.
the thinner the liquid = the better the viscosity (for our purposes that is)
the lower the viscosity = the faster we are able to pump our coolant.
the faster we are able to pump our coolant = the more efficient our cooling mechanism.
low numbers goooood. high numbers baaad.
The other way to measure viscosity is called the Kinematic Viscosity. It is measured by dropping a sphere into a bucket of liquid and measuring how quickly it reaches the bottom. It effectively measures the amount of drag upon an object passing through it and is measured in Stokes. The industrial standard is Centistokes (cSt). I haven't provided those figures because the Dynamic Viscosity is the important one for our purposes. But as with the Dynamic Viscosity, the lower the rating the better.
the Freezing Point, the Thermal Differential, and the Viscosity are the crutial figures to look at when making your decision.
Just a note here: the term "Glycol" in all these figures is short for Ethylene Glycol Antifreeze - Prestone to be exact - using numbers from their most potent antifreeze that they supplied me upon request via email.
The term "Isopropyl" in all these figures refers to Isopropyl Alcohol (rubbing alcohol aka 2-Propanol).
and Air is labled 02 in the chemical makeup. thats incorrect. it's just normal breathable air.
Keep in mind that water is the best stuff around for heat transfer. The closer we can get our liquid to the efficiency of water, the better. Water is the standard in all these figures and the standard in which we are trying to meet or exceed (when possible) when choosing an effecient coolant.
and as always, my knowlege is far from perfect so if you see something that i missed, please feel free to backchannel me at
language@speakeasy.net and we'll get it all fixed up.