Portable air conditioners typically do not require an extended period of time to sit before turning them on. Generally, it is recommended to let the unit sit upright for at least 2-4 hours before operating it. This time allows the refrigerant and oil inside the compressor to settle, ensuring that they are properly distributed before starting the unit.
During transportation or movement, the unit may have been tilted or laid down, which can cause the refrigerant to move to areas where it shouldn't be, potentially damaging the compressor if operated immediately. Allowing the unit to sit upright helps to avoid any potential issues and ensures the system operates efficiently and reliably.
It's important to consult the manufacturer's instructions specific to your portable air conditioner model for any specific recommendations they may have regarding the resting time before operation.