Zalman did a very good job of designing the HD160XT to provide excellent ventilation and case cooling. The HD160XT comes with four exhaust fans pre-installed. Depending on how it is mounted, the power supply may add to the overall airflow as well. The built-in fan control hardware/software provides excellent flexibility for selecting the right balance between cooling performance and noise.
When running, the four exhaust fans create a negative pressure area inside the HD160XT enclosure. This pulls cool room air into the enclosure thru the multiple vent openings. The top vent opening has movable louvers that can be adjusted to help fine tune the overall case airflow, especially in the CPU area.
1. Top cover – CPU area
2. Left side, rear – Expansion card area
3. Right side, front – Drive bays and additional CPU area airflow
4. Right side, rear – PSU area
Unfortunately, none of the vent openings incorporate any kind of air filter. I personally live in a relatively dirty environment so some kind of air filtration is always of interest to me (wood burning stove and lots of dogs and cats). Ultimately the HD160XT will go into a climate controlled AV rack in the new multimedia room I am building in my basement, so this won’t be an issue.
Temperatures were very good for the test system I installed in the HD160XT HTPC enclosure. On average the CPU, video card and HDD temperatures ran only 1~3ÂºC warmer with the case closed up when the fans were running at high speed while watching a movie or HDTV. However with all four fans running at high speed, the noise was significant and would be objectionable to the majority of HTPC enthusiasts. Slowing the fans down helped reduce the noise but still maintained good component cooling. With all the cooling fans operating at 5V the HD160XT was very quiet (not silent) but still maintained surprisingly good airflow and cooling.
* Measured 3′ away with an average background noise level of ~30 dBA.