Air Conditioning Repair Certification (ETI) Practice Exam

A scroll compressor employs an involute spiral mechanism to move refrigerant. This type of compressor consists of two spirals, one fixed and one orbiting. As the orbiting scroll rotates, it creates high and low-pressure areas, causing the refrigerant to be drawn into the chamber and pushed out as it is compressed in a continuous spiral motion. This design allows for a smooth flow of refrigerant with minimal pulsation, leading to increased efficiency and reduced noise levels compared to traditional compressors. The unique geometry of the involute spiral facilitates the compression process by sealing the refrigerant and managing its movement effectively within the compressor.

The other mechanisms listed—convection, conduction, and latent heat—relate to different physical principles. Convection involves the transfer of heat through fluid motion, conduction is associated with heat transfer through solid materials, and latent heat refers to the energy absorbed or released during phase changes. While these principles are fundamental in thermodynamics and can occur in various HVAC processes, they do not describe the method by which a scroll compressor specifically moves refrigerant.