How is the air quality in the air-conditioned library? Is it harmful to your health? Thank you for your answers.
It depends on whether there is a fresh air system. If there is no fresh air, the indoor air is turbid and the carbon dioxide concentration is high, it will feel stuffy. If there are people with colds or other diseases in this space, the germs on them are contagious and obviously bad for their health. So stay as little as possible.