Which type of compressor is not internally driven by a motor?

The open type compressor is distinguished by its design that does not include an internal electric motor driving the compressor directly. Instead, it typically employs an external motor that is mechanically coupled to the compressor. This external setup allows for greater flexibility in terms of the motor used, enabling maintenance, replacement, or upgrades without needing to replace the entire compressor unit.

In comparison, other types of compressors like the sealed, scroll, and rotary types integrate their motors within the unit itself. This design generally leads to improved efficiency, reduced noise levels, and a more compact setup, but it can complicate maintenance since any motor issues may require the replacement of the entire compressor. The openness of the open type allows for better cooling and can often handle varying operational demands effectively.