I called Atlantic Duct Cleaning as the authorized provider of Aeroseal in the Northern Virginia area. I wanted the ducts in my 1967 home to be sealed. I called in late August and was given an early October appointment. The service provided by this company was above and beyond what I expected. I thought they were coming only to measure the air pressure in my system and to blow the chemical used to air seal the ducts. I was wrong and I want to share my experience: Alfonso and his crew (Carlos and Edwin) arrived early in the morning of the day of service. I showed them the supply registers and returns and they started inspecting the ducts. It turns out my ducts were collapsed in some sections of the house, had large holes in other sections, or needed to be cleaned. Obviously, they did have to cut through some drywall in the ceilings to be able to diagnose the issues. They were super clean, vacuuming as they were cutting the drywall. They spent the whole day trying to fix what was fixable. At the end of the day, at around 4:30 PM, they unpacked the machinery to seal my ducts. The initial reading showed that more than 50% of my air was lost and everybody was pessimistic about the final results. However, after about 75 minutes (longer than the average treatment) of the process, my ducts ended with about 3.5% air loss. Before leaving, Alfonso even gave me recommendations about how to fix the issues with my ducts. I am very happy with the service they provided and I strongly recommend it. I now have an official certificate of the status of my air conditioning system.