Why Fan-less matters
Fan-less or fanless computers are common in industrial and commercial pc applications. And in basic explanation, it literally means a computer without a fan. While fans in computers can assist in cooling and airflow, however most probable cause of failure in industrial computers are from the fan as it brings in dust, debris, and other items from outdoors.
Most industrial and commercials applications tend to steer towards fan less computers for reliability and 24/7 always on performance. Having a fan-less solution is different from ventless. You can have a fan-less computer with vents for assistance with heat dissipation. Ventless computers are a lot harder to build as one needs to ensure hardware reliability with combined heat trapped in a space with no exhaust.
Building a computer with internal thermal management solutions and external heat dissipation fins is crucial when running fan-less industrial computers. Actineon's Siilent Series are designed specifically for fan-less operations.