The process of coating your ductwork in Aeroseal does not take long. However, setup and drying time must be considered. You can expect the entire process to take around six or more hours. It will take the technicians time to prep your ducts for the Aeroseal. The actual application of the liquid will likely only take thirty minutes to an hour. But, then it takes two hours for the liquid to dry.Make sure to ask your technician if they would prefer you to remain in the house during the process, or if you should find something else to do with your time that day.