Cleaning Air Ducts
Really dirt air: clean air ducts. Very simple method: use a mid-size vacuum with a long duct- not need person to go down to the basement. Cost: depends on the size of a whole house- heavy dirt: $300 – $600
Mold, Bacteria/Virus are plenty: need a contractor to clean and sterile.
Normally, a year, you need to deep clean again.
Service Company– a wide screen picture of duct(s) is taken with camera after cleaning.