Rear fan placement

[drakulton]

I have a Noctua NH-D14 that sits fairly close to the back of the PC case, about 50mm.
There's a 140mm case fan in the back reducing the gap to 25mm.
I also have a spare 140mm Noctua fan that could either be clipped to the back of the CPU cooler, not fitted at all or fitted to the back of the case. is there a preferred option?

Or option 3 fit the Noctua fan to the CPU cooler and fit the rear case fan to the outside of the rear grill.

Ta Muchly

 

[Danny75]

I'd go with the spare 140mm Noctua on the rear (inside) of the case, as long as it's quieter and/or pushes more air than the current rear fan. Don't think a fan fitted to the back is as effective. Like it further in where the action is, and its intake less obstructed.

I hate metal grills at the rear exhaust on cases. Noisier and more "splashback" of air. I cut it out of my case and replaced it with a ring-type guard. Only a few cases like Corsair 540 Air come with ring guard there instead of grill.

 

[drakulton]

Ha, now you've just given me food for thought. Perhaps fit the Noctua fan to the NH-D14 to get push/pull/push/pull and cut the back grill out of the H500P mesh, and fit the case fan on the outside with a ring type guard on the back of that.