Are computer fans enough for air movement in a non-enclosed area?

[camille1585]

I guess the thread title says it all.

I never had much mold issues with my orchids, until I acquired some more Dens a year ago. I have lots of issues with spotting and rotting leaves. I know that Dens like good air movement, and my racks don't get much. My plan was to wire up an old computer fan at the end of each shelf and put them on a timer to turn on at regular intervals during the day. However, while computer fans are more than enough for a terrarium set-up, do I need something more powerful for an unenclosed living room set up?