Had Brian and Nathan clean our ducts in our 30 year old mountain vacation rental. This house had been infested by every critter and bug imaginable. During the process of cleaning the ducts Brian and Nathan created a vacuum seal in each flex duct and blew out all the crud to include 2 petrified mice that had died in the ducts. Since the cleaning we could definitely tell the difference in the air flow through the ducts. We hope our heating and air conditioning system will be more efficient and save us a few dollars a year.