I have never found a fan blade that is reversible enough for cooling in both directions. some you can reverse to blow light debris and chaff from the radiators.

also, SPAL and Tri-Pac are the only electric fans that I found actually match their flow curves.

however electric fans are not that efficient and have air flows less than 25mph. why not make use of the speeds your going and use and use "ram air"


The problems we face today can not be addressed at the same level of intelligence we were at when we created them - Albert Einstein Or with the same level of $ - Me