|Ice, water bottles, thermometer, and water|
I put 16 ice cubes in each water bottle then topped off each to the rim with cold water. The Camelback bottle actually holds 22oz of fluid and the regular bottle actually holds 25oz to the rim. I placed both bottles outside in the shade on the deck in front of a fan. I turned the fan on low.
|Fan, watch, thermometer, and water bottles|
There you have it, after almost 2 hours the water in the insulated bottle was still 20 degrees cooler than the air temperature. These results would probably vary if the bottles were placed in the sun and if they were subject to constant shaking as they would when placed on a bike.
We'll be buying a few more insulated bottles soon.