How often should the air filters in HVAC systems be replaced?

Replacing air filters in HVAC systems every 1 to 3 months is generally recommended for optimal performance and air quality. This frequency helps ensure that the HVAC system operates efficiently, as clean filters can significantly improve air circulation and heating or cooling effectiveness. Regularly changing the filters also reduces the strain on the system, potentially extending its lifespan and minimizing energy costs.

Additionally, dirty filters can lead to dust and allergens circulating throughout the indoor environment, negatively impacting air quality. For households with pets or members who suffer from allergies, more frequent changes may be necessary to maintain clean air. The specific interval can depend on several factors, including the type of filter used, the environment in which the HVAC system operates, and household habits.

While other answer choices suggest longer intervals or conditional changes, they do not align with best practices for maintaining air quality and system efficiency.