Ducts not sealed properly cause leakage of unconditioned air into the duct system or can dump conditioned air into unconditioned spaces. Both of these reduce the capabilities of the heating and cooling system to meet the proper loads and increase energy usage. We can test for these leakages and remedy them by Duct Sealing.
Ductwork is sealed with UL listed duct mastic. This mastic is non-toxic and water resistant. After the ducts have the mastic applied they will have nylon panduit straps attached tightly to the metal collar at the beginning of the duct and the air distribution wyes. Unlike duct tape this method will not dry and peel away for the ductwork even after years of extreme conditions.
DUCT CLEANING? BE AWARE!
Read more before you decide. http://www.epa.gov/iaq/pubs/airduct.html. Flexible duct work can actually be damaged and become leaky, causing more debris to settle in them, not to mention energy loss.
Duct requirements have driven many low-quality contractors "underground" causing them to not get a building permit. Not getting a permit can have negative legal ramifications for homeowners.