Fan cooling a PCB on my Simple Metal 1403

[bbrown64]

As of late I have been printing parts that have take 2-4 hours to print. In that time I have not had any indications of the PCB overheating. However, I am one that thinks about preventative measures. In that area I want to fan cool the PCB on my SM 1403. I have several 40mm fans laying around that could be used. My question is this. Has anyone already done a PCB cooling project that has the part or parts already designed? I did a preliminary search but did not find anything on the subject.