How do I know if my car AC filter needs replacing?

To determine whether a car's air conditioning filter needs replacement, a comprehensive assessment can be made from multiple aspects. If the airflow feels significantly weaker even at the maximum fan speed after ruling out other malfunctions, it typically indicates a clogged filter requiring replacement. Visually inspecting the filter, if severe blackening, heavy dust accumulation, or physical damage is observed upon removal, replacement is advised even before the recommended maintenance interval. The standard recommendation is to replace the filter annually or every 10,000-20,000 kilometres. However, for vehicles frequently driven in sandy, dusty, or smoggy conditions or with heavy AC usage, the interval should be reduced to 6 months. During installation, ensure correct filter orientation (arrow indicates airflow direction) and consider selecting an activated carbon variant for enhanced odor absorption. Regular replacement not only improves AC efficiency but also reduces dust allergy risks, particularly crucial for individuals with respiratory sensitivities. Note that some vehicle models position the filter behind the glove compartment; consult the manual during removal to avoid damaging the retaining clips.