Guys talking in break room and we wondered what anti freeze they use in places like Alaska. Wouldn't that be good for area's like me right now at -5 degrees and just nasty cold air ? We we're just wondering.
All the information I can find says with little variation that:
Quote:
By itself ethylene glycol boils at 330F but it doesn't transfer heat very well and its freezing point is -8F. Water is added to improve heat transfer.
Here is a list of boiling and freezing point for Antifreeze to Water mixtures as measured at sea level.
30/70 boils 220F freezes 3F
40/60 boils 225F freezes -12F
50/50 boils 226F freezes -32F
60/40 boils 234F freezes -57F
It varies because ethylene glycol does not have a well defined freezing point, but the melting point is generally listed as +9 deg. F. The freezing point is somewhat higher.
That graph is one of my favorite graphs to post when discussions like this come up. It clearly shows the power of a solute in a solution vs. a pure substance. After 50% you are seeing the effect of the water on the glycol.
The sweet spot is definitely at about 65%. Once in a while we get someone posting about how they run straight antifreeze to get maximum freeze protection. This graph shows why that is a foolish notion (apart from the much lower specific heat capacity of glycol).
When a mixture is >50-55% glycol it doesn't expand when it freezes (into a gel, not a hard crystalline mass) and therefore won't crack things. So even in Oymyakon, Yakutia, Siberia 60/40 should be safe.
So 65% seems to be the solution for when it's science fiction cold out.
Correct, and when I said "sweet spot" I meant only for the lowest freezing point not the optimal mixture for operation. In general you shouldn't mix it any more concentrated than you need since the specific heat capacity of glycol is quite a bit less than water. Some coolants specify a minimum (and maximum) concentration which obviously should be observed.
So 65% seems to be the solution for when it's science fiction cold out.
I would say so. I usually aim for about 60/40. That way, if I'm over on the glycol side, I'm not pushing the limits there, and if I have a bit too much water, I'll still be over closer to 55/45 and have plenty of protection. I've seen vehicles freeze up before, but never one of mine.
Had one incident. We hit 40 below that night in Saskatoon, Canada. Had mushy ice in the rad but no damage. I try go to on the high side of 50 % with the glycol ever since.
SF
Like Charlie said pure antifreeze or a mix does not freeze solid but more like a slush or gel and does not expand as much.
Also they rarely shut the machines down when they are operating in temps that low.