The only way to ensure peak efficiency when using air conditioning is by changing the air filter on a regular basis. The filter’s job is to keep dust and other debris from making their way into your equipment. These contaminants need to be pulled out of the air before it’s pulled into an air conditioner in order to keep it operating as effectively and efficiently as possible. During a routine HVAC tune-up, the filter should be changed. However, you should learn how to do it yourself as well.