By doing so,it can let the fresh air in,which is benificial to our body.

By doing so,it can let the fresh air in,which is benificial to our body.

i don't think it's often in China.Maybe they just need some fresh air

THEY TOTALLY WASTE THE POWER ENERGY AND WASTE MONEY ,

To let fresh air come in

Air conditioning and heating systems are commonly used in both residential and commercial buildings, and are commonly controlled by thermostats. However, people using these systems may leave doors or windows open for fresh air or other reasons, therefore causing the air conditioning or heating system to operate at a nearly continuous level. This continuous operation of the air conditioning or heating system creates high electricity consumption and maintenance costs because leaving the door or window open will prevent the environment from reaching the temperature setting for the thermostat. This problem is especially acute in hotels and resort vacation rental facilities in which occupants are not responsible for, and probably are unaware of, high electricity, repair and maintenance costs. These costs are therefore borne by the owner or operator of the hotel, rental facility, or other building. Lack of knowledge may be one of the reason why Chinese do so.