NA-FD1 Fan Duct

The NA-FD1 fan duct kit makes it possible to significantly improve the performance of Noctua NH-L9i and NH-L9a series CPU coolers in Small Form Factor (SFF) environments where there is a gap of 5mm or more (up to 45mm) between the cooler and a perforated top or side panel. Bridging this gap, the duct prevents the cooler from taking in hot air from the interior and enables it to draw in fresh air from the outside through the perforated panel, which can, depending on the setup, improve CPU temperatures by as much as 5°C or more.

While the regular NA-FD1 is made from EVA foam and fixed with short plastic tubes, the 3D print design has been adjusted so that it works well as a 3D-printed part and can be fixed to NH-L9i and NH-L9a series coolers using M3 screws of the required length (height of the duct plus 15mm). 

Following the provided PDF guide, the height of the NA-FD1 3D print design can be easily adjusted so that it fits the gap between the heatsink and the case panel. Adjusting the FCStd file and exporting printable STL files requires FreeCAD, a free open source CAD software that can be downloaded at www.freecadweb.org.