Which type of mobile AC system will usually require additional time to extract all the refrigerant?

A mobile AC system that uses a variable displacement compressor typically requires additional time to extract all the refrigerant. This is because these systems can operate at varying levels of efficiency and may retain refrigerant in different components, making complete extraction more complex. Additionally, systems with multiple circuits or those that are particularly large may also extend the extraction time due to their design. Proper evacuation techniques and equipment are essential for thorough refrigerant removal.