Quote:
Originally Posted by CapnHand

The above link describes the thermal expansion of glycol solutions as follows:
"Coefficient of Thermal Expansion
Since most applications of brine solutions involve small to moderate temperature variations,
it is necessary to provide some expansion volume to absorb the expansion...due to temperature variations..." and goes on the provide the thermodynamic equation to calculate expansion coefficients.
As you can see from the graphs or an understanding of the equations, glycol DOES expand with decrease in temperature.
The issue becomes moot unless you leave the system charged; simply filling it doesn't do that. As long as you relieve the pressure, expansion is possible but I don't know why it would be worth the chance.