Noctua includes two premium NF-A15 fans in the NH-D15's huge packaging, allowing the end user to opt for either a single or dual fan setup. This is one of the aspects we tested to see how well this huge dual tower based cooler performs with either one or two fans. I don't mind the beige-brown color scheme of the Noctua fans as it has been one of their trademarks from the start. One directly spots a Noctua cooler by just looking at the fans :)

These PWM controlled fans are based on Noctua's own PWM IC design (NE-FD1 PWM IC) providing smoother torque impulses and reducing PWM switching noises. The utilized SSO2 bearing is also an in-house design thus Noctua doesn't leave any option open for error. Like mentioned before everything has been designed by Noctua's own R&D team from the ground up to perform as good as or even better than any competitor's offering, warranted at a lower noise/vibration ratio. Only drawback might be the added cost for the R&D and manufacturing costs.

The A15 fans are in fact 140mm fans in a rounded body, allowing them to be compatible with high end 150 coolers yet not interfering with your enclosure as it is only 140mm in height, The below illustration tells the tale, a huge fan in a more case compatible housing featuring smaller 120mm fan mounting holes (105mm).

Though there is more than just the beige-brown colors, everything has been done to enhance the static pressure and airflow and yet still being able to lower the noise. On the blades we can see the patented Flow Acceleration Channel technology leading to better efficiency and lower the vortex noise. Those that look closer to the frame itself can see the Inner Surface Microstructure again to aid airflow and pressure efficiency.

The integrated Anti-Vibration pads made form silicone minimize the transfer of vibrations while maintaining full compatibility with all standard screws or other mounting systems.