To ensure optimal performance and prevent any potential damage, it is generally recommended to let a portable air conditioner sit upright for at least 2-4 hours before turning it on. This resting time allows the refrigerant fluids to settle after transportation or any movement that might have occurred.
During transportation, the unit may have been tilted or shaken, which can cause the refrigerant to move around and not properly settle in the compressor. Allowing the air conditioner to sit upright helps to stabilize the refrigerant, ensuring that it operates efficiently.
It's worth noting that the specific manufacturer's instructions provided with the portable air conditioner should always be followed, as they may include specific recommendations or guidelines for that particular model. If the manufacturer's instructions differ from this general advice, it's best to follow their guidelines for the optimal performance and longevity of your portable air conditioner.