Wednesday, Nov 23, 2005 at 18:27
Nup, I disagree. Leave the
water in, at least until your butter starts to float and your cheese goes soggy. Nudenut, I think you are right in saying that leaving the
water in will make the ice melt faster, BUT, the presence or absence of ice doesn't necessarily mean that the the cooling effect will be better.
Look at it this way. As long as the
water is still colder than the temperature you want the cooler to be, say about 4 degrees, then it will still have the capacity to absorb heat. You want to maintain the greatest thermal mass as possible in the cooler so ice and cold
water absorbs as much heat as possible, rather than your food. (we are talking food here aren't we?). If you put three coolers in an air temperature of 25 degrees, one had 10kg of ice, one had 5kg ice and 5kg of
water, and the third had just air, the third would heat to 25 C first as air takes relatively little heat to raise the temperature of air 1 degree, the
water ice combo would be next as it takes much more energy to heat the ice,
water and air 1 degree, and the ice only cooler would take the longest, because ice requires heat to raise its temperature to zero degrees, latent heat to actually melt the ice to
water, and further heat to raise the temperature of the
water to 25 C. If you took all the
water out of the 5kg ice cooler, I think you would find that it would heat up quicker than if the
water was still left in it. The
water will also act as a better convective heat transfer medium for things sitting in the
water than air will, so it will cool things down faster if they are sitting in the
water.
Hmm, all this thinking is making my head too hot. I think I need to stick it in an esky full of ice, and
water, or no
water....too hard.
MikeyS
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