Which retains cold better Ice or Alcohol?

Question

I always keep things in my freezer to provide some thermal mass to retain the cold and keep the fridge from having to work so hard. Would bottled water retain cold better than bottles of booze because it freezes or would the booze do a better job because it doesn't?

Answer 1

OK but we're talking about several different things and the temperature range matters.

ice has a heat capacity of about 1/4 that of liquid water.

I'm not sure on alcohol but I'd guess its heat capacity is roughly 3/4's that of water.

So if you are trying to maintan a temperature below freezing the alcohol will work better.

However the phase change from ice to water is about 144 times as much heat absorbed with no temperature change as changing the temperature of water 1 degree.

If you talking about holding the temperature after just opening the door it won't make much difference the hot air entering the freezer will be easily cooled by either water or alchol.

Answer 2

Because the water is (probably) always going to stay frozen, then you can just use either. The specific heat capacity of alcohol and ice are almost the same, with alcohol being ever so slightly higher than ice, making it a slightly better substance to keep the freezer cold..

Answer 3

Liquid water has by far the highest thermal capacity of anything and is nearly twice that of ethanol but after it is frozen it is about the same. Alcohol that you drink is 60% to 96% water anyway.

Answer 4

As water froze, it released far more heat energy to become solid. Ice will take much longer to absorb heat than alcohol.

Ice therefore retains 'cold' better.

Answer 5

Water has a higher specific heat than ethanol (4.18 vs. 2.44).

I'm not sure you're saving any energy doing this since it takes additional energy to cool these items. There's no free lunch.