We feel cool when wind blows over because we are warm blooded. As the warm air near skin is blown away, the skin turns cool. Relationship of ambient temperature and wind speed is known as wind chill.
For plants, they are at the same temperature as their surrounding. Theoretically, local temperature can lower when water evaporates, until 100% RH. However, since you plan to blow using a fan, the moving air quickly evens out the temperature.
Probably you can wet a thermometer and blow using a fan. See if temperature changes. I doubt the cooling will be significant.
Just me view on the logics of it.. let us know how it works out..
