The integrity of the duct system directly impacts the performance of the oil furnace and a/c. The branching network of ducts transfers heated and cooled air to and from the rooms of the house. Even minor holes or flaws in the ducts allows conditioned air to escape. It makes it way more hard for the oil furnace or a/c to achieve the temperature setting on the thermostat. Leaks in the HVAC duct forces the heating and cooling system to run for longer cycles and results in far greater wear and tear. More frequent malfunction, higher energy bills, and shortened service life are some of the consequences. These same holes in the duct system also allow outside, dirty, unconditioned air into the home. Dust, exhaust fumes, bugs, and all sorts of pollutants can be introduced into the indoor environment, creating a safety and health issue. It is a fantastic idea to have the duct system checked by a licensed Heating & A/C company every couple of years. An Heating & A/C serviceman has the tools to effectively test the duct system for flaws and handle the sealing process. While duct sealing is rather fancy, it pays for itself through bi-weekly energy savings. The serviceman will first seal off the supply and return vents, before injecting pressurized air into the duct system. The pressurized air contains adhesive particles which attempt to escape through the holes. As the air passes through, the particles build up and gradually seal the many leaks and flaws. The Heating & A/C serviceman will repeat testing to ensure that the duct system is effectively sealed and provide a ipad generated report of the findings.