I did not really believe in duct cleaning until we bought a home in Cedarburg that was vacant for three years. We hired Ahrens Heating & Cooling that came with machines and qualified personnel. They removed so much residue and gunk from our system in a large professional vacuum machine that stood as tall as my 6 foot 1 inch frame. Those tanks were filled twice and totally took out all of the old mess in this old house.
We totally recommend Brion who heads his team of hard working personnel who did a super job! My wife has serous allergies and asthma but now breathes much better. We recommend his service to all who lived in their home for a while, and especially if you have pets.
Best regards to Ahrens Heating & Cooling. Call them!