Todd from RetroFrog has just designed an adapter that lets you mount a quiet 60mm Noctua fan inside your original Xbox. This is a #nocutmod: Simply bolt the Noctua fan (sold separately) to the shroud, then snap it into place. The price is under $10, with your choice of green or black plastic. More info below, including why you might want it over the 70mm model:
Fan Shroud Kit: https://retrorgb.link/xboxnoctuaadapter
600 Noctua Fan: https://amzn.to/3XlsiHt
Xbox fans (no pun intended ;p) might recognize that the original fan was actually 70mm. And in fact, Todd also made an adapter to support a 70mm Nexus Fan! So, why would you want this one?: Noise and availability. First, the Noctua fan is noticeably quieter than the Nexus, while moving about the same amount of air; No real internal temperature difference should be seen. Also, the Nexus fan isn’t available in all regions. Plus, the total price for everything is about the same, so this may be a better choice for most people.
Since you’re paying for shipping anyway, you might want to take a look at the Xbox Vertical Stand and 2.5″ HDD adapter Todd is also selling through Stone Age Gamer! This stuff feels a lot cheaper when you’re only paying once for shipping. Here’s links to everything else mentioned:
Xbox Vertical Stand
Xbox 3.5mm -> 2.5mm HDD/SSD adapter
70mm Fan Shroud
Nexus 70mm Fan