When our AC was serviced on our house we just purchased. We were informed they found feathers stuck on the coil. We had a group of contractors for air duct cleaning come out to give quotes. IVY's was a very fair in price for the quality of service preformed.
The guys working were friendly and gave their recommendations on what we should do, but were not pushy to sell us anything.
They were able to clear out all the ducts and clean everything up. They found a dead bird in the ducts and used some safe disinfectant to clean anywhere the bird could have been.
No dust or feathers were left over in the system. They sucked all the dust out to their machine in their van. I was very happy with their service.