An NH3 refrigeration system, evaporator, and condenser operate at -16°C and 32°C. What is the work done, refrigerating effect, and COP if:
1. Dry saturated vapor enters the condenser with sub-cooling.
2. Dry saturated vapor enters the compressor with no sub-cooling.
3. Dry saturated vapor enters the compressor with refrigerant leaving the condenser sub-cooled by 10°C.