Really Cool and Quiet Power Supplies?

Finally Some Quiet?

So how do vendors with cool and quiet power supplies that we review here get the cooling job done? While it's possible to find power supplies rated from 300 to 400 watts that use no fans for cooling, two vendors in our review take a different path. While they support temperature-sensitive cooling fans in their designs, these fans are only activated when absolutely necessary; otherwise these units employ only passive cooling techniques as well.