Josie asks: "I am considering getting my ducts professionally cleaned. Can you tell me if it will reduce the dust in my home and whether there are any other benefits to having this done?"
This question comes back every year, and although there is still hot debate on the subject, it appears to me that the answer is about the same it was 10 years ago. At least that is what I got from listening to the experts we interviewed on the show.
Really filthy dirty ducts should be cleaned by a professional who uses an outdoor vacuum, compressed air, and a skipper tube banging around in your ducts. He or she will have to open up the ducts at several places to do a good job. Most legitimate duct cleaning jobs are recommended by a furnace professional who has been working on your system and says it needs it. Most door-to-door duct cleaning is a waste of money.
Other than exceptional cases, dust stuck to the inside of your ducts does not add to or subtract from the dust in your home. It just stays there. What you can remove yourself by vacuuming all the floor grills and cleaning off the furnace fan, is about as good as you are going to get. Getting better furnace filters, and better filters on your vacuum cleaner (or even better, an outdoor exhaust on a central vac) will do more to stop dust than duct cleaning will. Cleaning the furnace fan will increase its efficiency, but you can do that yourself.
To check out the research reports yourself, go to the CMHC.ca site and in the search box enter: "duct cleaning". Actually there are some very well written papers here that are far more understandable than a straight research report -- and they may help you to decide if you need to clean your ducts or feel comfortable not cleaning them.