My client wanted a design for a personal cooler that could be attached to a standard thermos or similar insulated bottle. The bottle would be filled with ice water which would be pumped through some copper tubing. A fan would pull air through the housing and be cooled as it passed the tubing.
I designed the mechanical portion of the system (except for the pump assembly which isn't shown here). The assembly consists of a spiraled copper tube, housing, fan, and interchangeable mount. One end of the copper tube would be connected to the pump to push the cold water through. The fan is an off the shelf 80mm fan that can be run off USB. The mount itself is intended to be interchangeable to allow different adapters for different bottle types (Thermos, Hydroflask, Nalgene, etc)