Keep in mind:
1. The air cooler should always be placed in front of an open window. Only then will the air coming out of it be cool.
2. Use a table fan or air cooler before turning it on. Especially if the room in the house is hot, you should definitely turn on the fan for a while before turning on the air cooler.
3. If you put ice cubes in the water in the air cooler to keep the air coming from the air cooler cool, the scene will be the same as the air coming from the AC.