Techgage posted a review of Thermalrights tall HR-01 passive cooler

In the prospect of building a quiet PC, cooling the CPU can prove to be a problem. To take care of this 'tall' order, Thermalright brings us the HR-01. This passive cooler requires no fan at all to operate. If overclocking suits your fancy, they even offer a duct! . No fans are needed, but they do throw a duct into the mix.

Thermalright HR-01-K8 CPU Cooler Review