The answer to 'how to maintain duct cleaning' is to have your HVAC ducts professionally cleaned every 3-5 years, or more frequently if you have pets, smoke indoors, or notice increased dust or allergens in your home. Professional duct cleaning helps remove built-up dust, debris, and contaminants that can reduce airflow and air quality.
Between professional cleanings, you can help maintain your ducts by regularly changing your HVAC air filters, sealing any visible duct leaks or damage, and using a vacuum attachment to lightly clean the visible portions of your ductwork. However, it's important to avoid attempting a full DIY duct cleaning, as this can damage the system or spread contaminants if not done properly.