I had someone out to clean my ducts last weekend. He took a blue bag up in my attic. He came back down in just a few minutes and said I had mold and he even showed me a picture of something saying it was mold but I couldn’t really tell. I refused his service to take care of the mold. He went back up in the attic for a little while and then came down. I never heard any sounds that he was actually up there doing anything. How do I know if he actually cleaned the air ducts?
If I could rate this company a zero I would in a heartbeat. I purchased the service off of Groupon and to say that the groupon was misleading is an understatement. I was at work and my girlfriend was at the house when they got there (keep in mind it took six months for them to be able to get there because they were over booked). They tried to upcharge my girlfriend $250 immediately upon getting there. I told her to put me on the phone and spoke with the guy myself. He said that he would have the manager call me and that he would just start on the service. I received a text from my girlfriend 10 minutes later that the people had left. I never received a call from the manager. They didn't do all vents in the house. All they did was the main floor. It was a pathetic attempt to say the least. 

The original furnace was a coal fired “octopus” design which had no blower to circulate the air but relied upon warm air rising to distribute the heat. That also means that the system breathed air in from the basement and most of this type did not have a cold air return system. At some point (probably in the 1940’s) the system was upgraded to a forced air gas furnace. The upgrade included replacing the 12″ diameter air ducts exposed in the basement with 6″ ducts and a cold air return system of ducts from the two (only two) air returns on the first floor.
You should be aware that although a substance may look like mold, a positive determination of whether it is mold or not can be made only by an expert and may require laboratory analysis for final confirmation. For about $50, some microbiology laboratories can tell you whether a sample sent to them on a clear strip of sticky household tape is mold or simply a substance that resembles it.
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