During operation, a facility may utilize many sensors, such as cameras, to generate sensor data. Some of these sensors may be housed within protective enclosures. The enclosures may be inside specially controlled environments, such as refrigerators, freezers, and so forth. During operation of the facility, moisture may accumulate on these enclosures, impairing the ability of the camera to acquire an image through the window. Described are devices to selectively heat a viewable area of the window such that moisture accumulation is reduced with minimal power use.