Dust clogs the filters and reduces airflow and cooling effectiveness. Change or clean air filters at the start of the cooling and heating seasons for good system performance. Make sure the filters are the right size and are tightly installed so they do their job. Keep condensers clear. Your air conditioner cools the building by transferring heat to the outside.
Most systems have air-cooled condensers with a fan and condensing coil on the roof or in the alley.
The space around these units must be kept clear so air can move freely. An outside air economizer uses cool outside air in the mornings to cool your building instead of running the compressor. This saves energy, but the economizer must be maintained to work. You can tell if your unit has an economizer when there are automatically operated dampers in the return air and outside air. The outside air damper should be closed at night when the unit is off, and open when cooling is required and the outside air is cool.