Should a grain drying fan's intake face south?

[Aceface]

We are just about to upgrade the fan capacity on the grain store and I have been reminded that when we fitted the original fan I was told by an "expert" that the intake should ideally face south so as to make use of the sun's energy more efficiently. Surely this is non-sense as the fan will suck 10s of thousands of cubic feet of air per minute and therefore the air quality is the same in the whole of the general area surrounding the fan regardless if the sun is shinning in to the air intake. Any observations will be gratefully received, thanks in advance.

 

[chickens and wheat]

our north facing one gets started later than the south one, it just doesnt feel as dry , dew still on grass in shadow of shed near fan house. but not sure if it makes a real difference.
south one is also 20 ft up so its different anyway.