Cooling costs count. Unnecessary exposure to high ambient temperatures can significantly shorten a monitor's life. In many installations, a monitor may be located near the top of an enclosure, without any active cooling. And temperatures at the top of the enclosure can range from 10 to 20 degrees hotter. Although monitors may be designed to operate at a high temperature, it's not a good practice to operate them at or near their maximum specifications for extended time periods.
High temperatures reduce the longevity of electronic devices.
Cooling a CRT in a sealed enclosure can be expensive. A big advantage of flat-panel displays is that they generate little heat. Therefore, heat management is easier and cheaper. In some cases, cooling may not even be necessary. Stray magnetic fields emitting from arc welders, motors, DC power buses, transformers, and motors are common on the plant floor, and can result in screen noise, degraded color purity, or severe geometric distortions in CRT images.