Which statement correctly describes a hermetic compressor?

A hermetic compressor is characterized by its construction, which involves welding the entire unit together in a sealed system. This design prevents any air or moisture from entering, preserving the internal environment necessary for optimal performance and efficiency. Because of this sealed construction, hermetic compressors do not allow for field repairs; if a failure occurs, the entire unit typically needs to be replaced rather than repaired on-site.

The other options do not accurately represent the nature of hermetic compressors. For example, options that mention bolted construction suggest that repairs could be made more easily, which is not true for hermetic types. Additionally, variable speed motors and designs for easy disassembly are features associated with different types of compressors, not hermetic compressors.