Final answer:
A refrigeration system can only be refilled with refrigerant after proper evacuation is performed to ensure safety and system integrity. This step is crucial for adherence to regulations and environmental considerations.
Step-by-step explanation:
The question pertains to the conditions under which a refrigeration system can be refilled with refrigerant. The correct answer is that a system cannot be refilled with refrigerant unless proper evacuation is performed. This process ensures all non-condensables and contaminants are removed from the system before adding new refrigerant to prevent any possible damages or inefficiencies. This aligns with safety and environmental regulations that professionals in HVAC (Heating, Ventilation, and Air Conditioning) must adhere to. Additionally, proper evacuation is a critical step that maintains the integrity and performance of the refrigeration systems, whether it is for a refrigerator, heat pump, or a larger HVAC system. The environmental aspect is also significant, considering the global efforts to reduce greenhouse gases and transition towards climate-friendly technologies, which include careful management and handling of refrigerants.