Possible cause:

The doors and windows of the room are not closed

Solution:

Make sure that all doors and windows are closed

Possible cause:

There is direct sunlight exposure
Solution:

Closing some curtains and/or coverings can improve the appliance's operational performance and enhance economic efficiency

Possible cause:

There is heat source in the room

Solution:

 Remove the heat source if possible

Possible cause:

The exhaust pipe is not connected or is blocked

Solution:

Connect the exhaust pipe and ensure it can operate normally

Possible cause:

Temperature set too high

Solution:

Lower the temperature setting

Possible cause:

Air filter blocked by dust
Solution:

Clean the air filter

Possible cause:

The ground is not flat

Solution

Place the machine on a flat surface if possible

Possible cause

This sound originated from the flow of the internal refrigerant

Solution

This is normal