Changing Your Air Conditioning Filter from Greeniacs.com:
1. Determine whether your system is a furnace system or a forced air system. In a forced air system, the filter will be over a vent, where the air comes from. In a furnace system, the filter is directly attached to AC unit itself.
2. If the filter is near a very dusty or dirty area, sweep or vacuum the floor.
3. Make sure that the system is turned off before you touch any part of the filter.
4. If you have an AC unit, pop or slide open the panel door.
5. The filter can be either slid out of the AC unit or easily taken off of a regular forced air system.
6. If it’s a disposable filter, carefully measure the length and width of the filter. Then go to the hardware store and buy filters that are the same size. Go to step 9.
7. If it’s a replaceable filter, take the filter out to a solid, clean surface outside and spray it down thoroughly with water. Do not use detergents, since this can actually make the dirt stick to the filters.
8. Let the filter dry outside.
9. Put the filter back in, making sure to line up any guide arrows correctly.