Clean window units once a month when you are using them regularly.
Here’s what you need to do:
- Turn off the power, remove the unit’s front panel and vacuum any visible dirt from the interior coils.
- Remove the filter (with newer units, the filter slides out the front) and wash it at the kitchen sink, using a mild solution of dishwashing liquid and warm water.
- After the filter dries, put it back in the unit.
- Brush leaves, dust and dirt off the outside of the unit.