The main reason for the energy-saving effect of the closed cold/hot passage is (). (Multiple choice)

The main reason for the energy-saving effect of the closed cold/hot passage is (). (Multiple choice)
A . Isolating hot and cold air, avoiding the confusion of hot and cold air and improving the utilization of cold air.
B . It can increase the air supply temperature of the air conditioner, thus reducing the energy consumption of the air conditioner.
C . The closed heat channel can increase the return air temperature and improve the cooling efficiency.
D . Reduce the humidification power consumption by increasing the supply air temperature and reducing the power consumption of humidification.

Answer: ABCD