As conditioned air flows through the ducts from heating and cooling equipment to the spaces where people live, excessive length, sharp bends, crimps, and crushed or disconnected ducts can compromise air flow, reducing comfort and causing the HVAC system to work harder than necessary. Professionally designed and installed comfort delivery systems will have proper-length ducts that are well-supported with proper insulation, air sealing , and layouts free from kinks and sharp bends that restrict air flow.