The answer to 'when to replace duct cleaning' is that you should have your air ducts professionally cleaned every 3-5 years, or more frequently if you have pets, smokers in the home, or have recently completed a home renovation project. Duct cleaning helps remove built-up dust, debris, and allergens that can circulate through your home's air, reducing indoor air quality. Over time, your ducts may also become damaged or develop leaks, which can impact the efficiency of your HVAC system.
Regular duct cleaning is an important part of home maintenance, but it's not something most homeowners can do effectively on their own. Hiring a qualified HVAC technician to inspect and clean your ductwork is the best way to ensure it's done properly and safely.