"Tiny Cooling Fan" works by energizing coil in the AC motor to rotate in a magnetic field force. Convert electrical energy into mechanical energy, and because the coil resistance, it is inevitable that there are some electrical energy to be converted into heat. Fan work when the indoor temperature is not only not reduced, it will rise. The reason is: When "Tiny Cooling Fan" work, since the current through fan coil wire is resistance, it will inevitably generate heat so that the ambient temperature rises. But "Tiny Cooling Fan" to make the air flow around them, the skin secretion of sweat evaporation, take away the body heat to achieve the purpose of cooling the body. But the indoor temperature did not decrease, so fans in use for some time, it will reduce cooling sensation.