Why control dual cooling fans seperately?

[J. Fast]

Another question I've always pondered and maybe someone can chime in. Is there an added benefit to puller fan over pusher fan? If they move the same cfm is one more efficient than the other?

[aronhk_md]

Another question I've always pondered and maybe someone can chime in. Is there an added benefit to puller fan over pusher fan? If they move the same cfm is one more efficient than the other?

I think that very much depends on the blade design......and really the only way to tell unless you did the designing yourself is to try it each way and to figure it out. I think it will vary with each fan. Most of the fans I have seen have been designed to pull....but that doesnt mean they wouldnt work well pushing. Either way having it all well shrouded will be important so that you are ONLY pushing/pulling through the cooling fins.

But there should be no COOLING benefit for one over the other if they move identicle units of air through the radiator.