We just had our ducts cleaned, which have not been done for quite some time, and, already I am noticing a big difference in the air in the house. I have Cardiovascular problems along with acute Asthma. and severe Allergies, giving me a very difficult time with my breathing. In just a few hours time, even before all Ducts were cleaned, noticed a difference in the air. My husband also has extreme Cardiovascular and High-level sensitivity to air, sometimes resulting in Infections, and, he too said he noticed a difference in the air almost immediately. The Duct Cleaning Team are very respectful, friendly, very kind, and, bend over backwards to serve you. This definitely was a very strong point for us...a definite 10 on the scale of 1 - 10. We most definitely would recommend Fresh Air Exchange