I did this experiment in 2012:
All three of the coolers I am testing with are identical, and have similar wear and tear. The insulation thickness should be withing manufacturer tolerances. Which should make the test of just the ice management viable.
My GF, a researcher says I am still not being scientifically viable because I don't have a control cooler without ice and my sample size it too small. Maybe we can get NRS to step up and make a fancy video about cooler management. Personally, I'm hoping for Mythbusters.
I'm betting that the drain cooler will heat up the fastest and the jug ice will last the longest, but not keep the cooler the coldest because the ice and cold water is isolated to one part of the cooler. Now that I started this darn thing, I am thinking i should have raised the test water on a block so that it was not in direct contact with the cooler water... I guess I may need to repeat the experiment if the results are close.
Here are the results:
A tie between the no drain cooler and the jug... Why you may ask? Well the answer is simple math.
If you imagine the ice when placed in the cooler is 100% frozen we can compare what happens when the ice melts. When the ice is at 50% in the no drain and jug coolers, it meant that 50% was frozen and 50% was unfrozen but still in the cooler and still under ambient air temp. When the drain cooler was at 50% frozen, the other 50% of unfrozen ice was running down my driveway. Even though the unfrozen portion of ice was above 32 degrees, it was still lower than the ambient air temp and therefore helping to keep the cooler cold. By taking that unfrozen portion and draining it out, you are in the end reducing the amount of cold "energy" remaining in the cooler and replacing it with air which is much more volatile to temperature changes.
Now, to drain or not to drain is more than just keeping your cooler cold, it is about good cooler management which in my opinion is keeping cooler water out of my food and making the cooler easier to carry from the boat to camp and back. If I am not worried about my cooler warming up, I will continue to drain my cooler. If I am worried about my cooler warming up I will not drain.
Finally, it seems like the best option would be to freeze your ice into jugs which looks like the best of both worlds because you keep all the cold energy in the cooler and you reduce the likelihood of your salami swimming the backstroke in your cooler.
I attached the chart of my results. I would suppose if you repeated this experiment with more starting ice your coolers would stay cooler for longer, but you should end with similar result. I welcome anyone to give it a try and report back what happens. Until then I am sticking to not draining your cooler as the best way to keep it cold and anyone who thinks otherwise is just talking through their arse....
Originally posted here: to drain or not to drain