Traditional square metal ducts made a difficult task to install an air conditioner as a weekend project. It will require tools and skills that most homeowners do not have. But modern round ducts, also known as flexible ducts, come folded and you just have to pull them to stretch them to the proper length. This type of ductwork makes installation of ducts for your air conditioning unit is much more than a do it yourself project.



  1. Design the layout of the ducts. If necessary, outlines the attic of your house or basement to help you determine where the line should run.
  2. Measure the distance from the central point of connection of the air conditioning unit to the ventilation or log grid for each duct.
  3. Consider any turn that the ductwork should do by adding twice the duct diameter for each turn.


  1. Cut sections of conduit lengthwise using sharp scissors or a knife. Metal scissors may be needed to cut the wire around the spiral conduit.
  2. Look at the end of the duct. You will see three layers. Wrap the two outer layers 2 to 3 inches (50 to 76 mm) at each end of the ductwork to expose only the innermost layer. Slide this layer into the connections on the air controller of the air conditioning unit and into the air or log.
  3. Roll the two outer layers down through this connection and wrap the connection several times with tape. Secure it with a metal or plastic strap to hold conduits.
  4. Repeat the process for each of the vents in your home.