what USAFRet and n0ns3ns3 have said - i'm running a noctura NH-U14S cooler and even in 1 hour long video rendering jobs with the cpu running at 92-97%, i'm seeing max temps of 65C on one core, others at 58-64C. Why introduce the possibility of a water leak in your case and frying everything when there's no gain or return for the risk?
That NH-U14S is $62 on amazon, and hell, even the D15 monster is only $89