If there is stuff in the ducts, the fact that it’s laying there and not being blown into the rooms is proof positive that it is hurting no-one. The 5-6 exceptions you cite in this article I’ll buy, but only with the caveat that at least some of those could have been avoided by proper protection (during remodeling for example) – and if asbestos/lead/whatever winds up in your ducts- the remodeling contractor should be the one paying to remove it.
So I purchased a Groupon to have this service done on my HVAC. I waited like 3 weeks or so since I was not using the heat or AC and I was in no hurry. So, on the day of my scheduled appointment which was 12noon I get a call from their office at 12:05pm that they are running late and they are 2 hours away...How did they manage to end up 2 hours from my house? Odd. Anyway, the girl tells me that they can't make the appointment today and will have to reschedule 30 days from now. What? 30 days from now? I was expecting perhaps tomorrow or the next day, not 30 days from now. This is extremely poor customer service and poor time management. Their leadership team should be reprimanded or replaced. I don't know how this company can stay in business when their business practices are so disorganized and they cannot even manage a schedule efficiently. I would NEVER recommend this company when they treat the customers so poorly. Their front office person should be retrained or fired since she does not have the skills needed to deal with customers. I would go so far as to fire their Office Manager or perhaps the Manager of this company. Well, at least they did not show up and provide poor service as it appears they did in the other customer reviews.
Another sketchy claim made by most duct-cleaning operations and their trade association is that dirty ducts and equipment overburden heating and cooling equipment, which wastes energy. Again, it intuitively makes sense that a cleaner system will run smoother and last longer — after all, that’s why we and HVAC-equipment manufacturers and repair services recommend that you regularly change your filters. But the page “Benefits of HVAC Cleaning” on the National Air Duct Cleaners Association (NADCA) website stretches this benefit too far by stating: “According to the U.S. Department of Energy, 25 to 40 percent of the energy used for heating and cooling a home is wasted.”
You may consider having your air ducts cleaned simply because it seems logical that air ducts will get dirty over time and should be occasionally cleaned. Provided that the cleaning is done properly, no evidence suggests that such cleaning would be detrimental. EPA does not recommend that the air ducts be cleaned routinely, but only as needed. EPA does, however, recommend that if you have a fuel burning furnace, stove or fireplace, they be inspected for proper functioning and serviced before each heating season to protect against carbon monoxide poisoning.