Regular maintenance of ventilation systems, if you have one, provides for the replacement of filters. Depending on the model of the device and the frequency of its use, the filter must be changed or cleaned once a month or once every three months. As a rule, the only reliable way to find out if time has come to change the filter is to check it regularly. If the filter is covered with a thick layer of dust, then the time has come either to wash it or install a new filter in the air conditioner.
