Regular maintenance of HVAC systems, including changing filters and cleaning ductwork, can help improve indoor air quality. Additionally, installing air purifiers and ventilation systems can help remove contaminants from the air.

It's recommended that you change your air filters every 1-3 months, depending on factors such as usage, air quality, and the type of filter you're using.

Signs that your HVAC system may need to be repaired or replaced include poor airflow, unusual noises or odors, high energy bills, and frequent breakdowns.

Signs that your HVAC system is not running efficiently include uneven heating or cooling, poor airflow, and high energy bills.

Common HVAC problems include refrigerant leaks, clogged filters, malfunctioning thermostats, motor failures, damaged fans and compressor failure.

The average lifespan of an HVAC system is around 10-15 years, although this can vary depending on factors such as usage and maintenance.

Regular maintenance for HVAC systems includes changing air filters, cleaning coils and ductwork, inspecting electrical components, and checking refrigerant levels.