Some 4 or 5 years ago a Salesman was trying to sell me some Stirling Engine Evaporator Fans. These engines utilised the cold evaporator coils in order to work the piston and thus rotate the fan blades. At the time I had no use for such fans and he left. I cannot remember the name of the company that manufactured these devices and have not been able to even find anyone who knows of this type of technology. Can any one help ?