Fans are an integral component in cooling modern computer systems. In order to comply with safety standards in place with respect to fans, fan enclosures are required to prevent injuries resulting from fans during, for example, service of computer systems. Product safety testing companies, such as Underwriter Laboratories, perform certification testing on fan enclosures to ensure they meet safety standards.
One general rule for ensuring safety is the so-called “finger test,” wherein any fan enclosure that prevents a finger from accidentally contacting a moving fan is considered sufficiently safe. Those skilled in the art will appreciate that many different designs exists that meet the finger test. However, those skilled in the art will also appreciate that such designs must also be made to not overly impede the airflow of the fan.