How do we make the cold rooms

What are the main components of cold rooms? at least eight important parts we should know, 1. the cold room panels, 2. cold room doors, 3. the refrigeration system, 4. evaporators, 5. expansion valve, 6. control panel 7. cooper pipes, 8. refrigerant. and engineers will put them together based on the required dimension, temperature and voltages, then we will get the desired cold rooms