As the name suggests, the air cooler only allows to cool slightly. To function well, it needs to be in a dry and very hot environment. It then makes it possible to drop the temperature and slightly increase the humidity. By cons we can not set a temperature to reach and therefore we can not strongly change the indoor temperature. An air conditioner makes it possible to reach and maintain a desired and precise temperature. However, it is a more bulky and more expensive device. We cannot choose one device for you over another. You decide according to your environment.