I was hounded by my local heating and air conditioning company to get my ductwork cleaned.
Every single time I would have one of their certified heat and a/c specialists out to my house to do my seasonal HVAC tune up and check ups they would tell me that I should seriously think about paying to have my ductwork cleaned because it would improve the air flow in my home.
I kept telling them that I was fine with the air flow and that I did not notice anything wrong. And so long as my central heating and air conditioning system was in one piece and in no risk of dying, I would pass on getting the ductwork cleaned because it was an extra cost I really did not want or need. Finally after several months of this I decided to give it a try because I was sick of hearing it. And then of course if I seen no difference in the working of my central heat and a/c unit I would call the local heating and cooling company to complain and demand a refund for the ductwork cleaning. I had thought that they were pushing this to try to make a commission. But no! They were right! After I got my ductwork cleaned I could not believe how much better the air flow in my home was and how fast the central heating and air conditioning system either heated or cooled my home! It actually helped save me money on my electric bills too because I did not have to run the HVAC system as often!