The answer to 'when to clean air duct cleaning' is that it's generally recommended to have your air ducts professionally cleaned every 3-5 years, or more frequently if you notice signs of dust buildup, mold, or pests in the system. Regular cleaning helps improve indoor air quality, extend the lifespan of your HVAC system, and prevent potential health issues.
The frequency of air duct cleaning can vary depending on factors like the age of your home, the number of occupants, whether you have pets, and if anyone in your household has allergies or respiratory conditions. It's a good idea to have a professional inspection done first to assess the condition of your ductwork and determine the appropriate cleaning schedule.