I am very familiar with united air duct cleaning and their unscrupulous tactics they play. I own a similar business and companies like this make all of us look bad. They test for mold and sell very expensive mold treatments, but in texas the law requires a 'mold remediation license' to perform such services. They claim their people are employees when in fact they're subcontractors and are paid accordingly. Their cleaners are paid on a commission basis and are instructed to sell any way they can even if it's with lies. Most of their people are hired for their sales ability and have little or no experience cleaning air ducts. Companies such as this eventually fade away, but in the meantime they will try to swindle as many people as they can