You can't. Can the air conditioner be affixed with the first-class sign privately? Because the first-class sign of air conditioner belongs to the first-class energy efficiency sign and is the most energy-saving sign. If an air conditioner vendor actually sells an air conditioner with a three-level energy efficiency label in the process of selling air conditioners, but the air conditioner is labeled with a first-level energy efficiency label, it is misleading consumption, and it needs to bear legal responsibility and compensate customers for economic losses.