Hi I use a H115i on my 9700k at the top of my case. I have it as an exhaust with 3 intake fans. 2 front and 1 back. Works well.
After much extensive testing on UTube (Jay's Two Cents & Linus Tech Tips are 2 good channels to watch) It really does not matter.
If you do mount it on top then exhaust is better but not for cooling reasons but so it does not suck in so much dust.
General rules are that you want more fans blowing in (through dust filters) than you exhaust called positive pressure. This is the best configuration to limit dust from inside your pc.
i have mine mounted in the front with the fans pulling air.. helps with less dust, but it does not matter where you place what ever works for your case...