I read about the Duct Cleaning Specialist in a newspaper article. I have also been reading a book by Jeffrey C. May (My House is Killing Me) which emphasized the importance of thorough duct cleaning utilizing brushes and not just a vacuum. I was pleased to see that the Duct Cleaning Specialist does use brushes and so I hired them. The photos of my ductwork which have been cleaned numerous times over the years, showed a serious buildup of material, indicating that previous cleanings had not been effective. However, after the cleaning this time, photos revealed the ducts are now truly clean. This is important to me due to allergy issues. I am pleased with the service and also, the technician told me that my blower was clean and therefore did not require cleaning--thus my bill was reduced from the original quotation.