What is stack effect?

What is stack effect?
Stack effect is a natural phenomenon of air movement driven by the difference in air density between the exterior and the interior of a
Heat dissipation utilizing the stack effect :
RAVEN RV01 chassis thermal design: As shown in the illustration, the area around the main component area is sealed off, only the bottom part of the chassis has intake vents. When the air around the system components gets heated, its density decreases and moves upwards, creating the stack effect.
The main heating components in the RAVEN RV01 such as graphics cards and the CPU are better arranged to take advantage of the stack effect than normal ATX chassis.
The benefits stack effect design in the RAVEN RV01
  1. More efficient airflow
    Due to stack effect and the layout that takes advantages of it, the air inside the RAVEN RV01 has the natural tendency to rise up. This enables fans pushing in the same direction to achieve higher airflow and efficiency. As a result, lower speed fans can be utilized to achieve great cooling performance and save energy.

  2. Quieter operation
    In order to create stack effect, the main component area is sealed off from the exterior environment. Noise generated from heatsink fans, hard drives, graphics cards, etc…do not have direct path to the exterior as seen in some chassis with large vents on side panels.

  3. Reduce dust build-up
    The RAVEN RV01 is designed with positive air pressure in mind so dust does not enter the chassis from miscellaneous gaps. Case fans are also positioned to blow air in parallel direction as the motherboard expansion slots so when the system stops running, dust does not fall back and accumulate on the installed expansion and graphics cards.

  4. Prevents heavy expansion cards from warping
    In traditional chassis design, cards are inserted into the motherboard slots at an angle that puts pressure on the expansion or graphics board. With high-end graphics cards now becoming heavier than ever, the chance of board damage due to warping is increasing. In the RAVEN RV01, the motherboard is positioned 90 degrees clockwise so the weight of the expansion and graphics cards are shifted to the stronger chassis rear plate as opposed to the board itself.

Stack Effect cooling RAVEN RV01 case - part 1
Stack Effect cooling RAVEN RV01 case - part 2