http://www.eurogamer.net/articles/digitalfoundry-why-xbox-one-is-cool-and-quiet
Our information suggests the Xbox One design is based on an ambitious brief, essentially impossible to test in anything resembling real-life conditions, and so the company played it safe, putting unit reliability first. A highly placed source says that the console has been designed with a ten-year lifecycle in mind and that it is designed to be switched on for that entire period.
Despite the near-final hardware present at E3, the conditions made it impossible for the any kind of audio testing to be carried out on-site, but developers working with the hardware tell us that in its idle and low-activity states, the unit is entirely silent and you can barely feel any heat being output from the unit's vents.






