Some of the main differences between an air cooler and an air conditioner are as follows:
AC works on a relatively lower noise level as compared to coolers. Coolers, on the other hand, are very noisy.
Coolers, if used in closed rooms, cause an increase in humidity and a decrease in cooling. Hence
Ventilation is a must for Coolers. AC, on the other hand, requires no Ventilation.
The cooler requires water to be filled for proper working. In the case of AC, the refrigerant is required.
Cooling of Ac is more as compared to cooler.