NA-FD1 performance: what to expect?
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 from the outside through the perforated panel.
In tightly packed, ITX-based Small Form Factor builds, hot air can accumulate around the socket area, so drawing in fresh air from the exterior can make a massive difference in CPU temperatures. In tests with various configurations, typical improvements in CPU temperature of 4-6°C have been measured:
-with-without-NA-FD1-fan-duct-kit.jpg&w=3840&q=85)
While the results can vary from setup to setup, the NA-FD1 typically provides a substantial improvement, making it a simple yet smart, flexible, and cost-effective way of boosting the efficiency of NH-L9a and NH-L9i series coolers!
Mentioned products
Explore the products featured in this article.
NA-FD1
Related articles
Want to know more on this topic? Explore relevant articles and resources.
NSPR: Noctua Standardised Performance Rating
Noctua’s Standardised Performance Rating (NSPR) is a platform-independent classification system that allows customers to compare the efficiency of Noctua CPU coolers at a glance.
The Fractal Design Ridge and the story of “less is more“
05/05/2026
Discover the best Noctua CPU cooler and GPU setup for the Fractal Design Ridge case. See how a custom duct and removing extra case fans unlocks SFF performance.
NH-D15 G2 vs. NH-D15 performance data
With an NSPR (Noctua’s Standardised Performance Rating) score of 228, the NH-D15 G2 sets a new performance benchmark. But how does it compare to it's predecessor?
Offset AM5 mounting: technical backgrounds
Noctua’s AM5 offset mounting bars shift heatsinks to the south side of the AM5 socket. But why is this necessary, and how much does it improve cooling performance?