Clogged or dirty duct systems can trigger a domino result of mechanical troubles. The buildup inside ducts spreads to other areas of the HVAC system, like blowers and coils, in which it can lead to overheating or failure. Why commercial air duct cleaning is so important cannot be overstated. From https://cashtfrcl.worldblogged.com/46370067/top-ducted-air-con-maintenance-secrets