Choosing the right specifications 6 Inch Insulated Flexible Duct R6 6 inches inner diameter by 25 feet long Wide Application 6 Inch Insulated duct R6 ,has a wide range of applications in commercial and residential HVAC systems. The insulation provides thermal resistance, which helps to reduce heat transfer and improve energy efficiency. Air conditioning systems 6 Inch R6 insulated Flexible ducting are commonly used in air conditioning systems to transport cool air from the air conditioning unit to different parts of a building. The insulation helps to prevent heat gain and keep the cool air at a consistent temperature. Heating systems 6 Inch Duct insulated R6 are also used in heating systems to transport hot air from the furnace or heat pump to different parts of a building. The insulation helps to prevent heat loss and keep the hot air at a consistent temperature Ventilation systems R6 insulated duct hoses are used in ventilation systems to transport fresh air from the outside into a building and to remove stale air from inside the building.