The evaporative cooler was the subject of numerous US patents in the 20th century; many of these, starting in 1906,[REF] suggested or assumed the use of excelsior (wood wool) pads as the elements to bring a large volume of water in contact with moving air to allow evaporation to occur.
Externally mounted evaporative cooling devices (car coolers) were used in some automobiles to cool interior air-often as aftermarket accessories[REF]-until modern vapor-compression air conditioning became widely available.