As the very least, you should clean your air conditioner’s filter once every three months. However, it is also recommended to check on the filter once every two weeks to clear any buildup as it happens.
To put it simply, an air cooler is easier to install, generally cheaper up front, and costs less to operate, however their cooling performance is found wanting, and the humidity they add to the indoor air can be quite uncomfortable.
When the evaporator absorbs heat from the moist air, the water vapors in the air condenses into water droplets. This, in effect, will reduce the humidity in the air being blown out of the air conditioner.
The buzzing noise that you’re hearing may be coming from loose parts or from small debris lodged in your aircon. It could also be because the wiring has gone bad. Whatever it is, you should take action right away to prevent further damage to your air conditioner.