To find companies that provide duct cleaning services, check your Yellow Pages under "duct cleaning" or contact the National Air Duct Cleaners Association (NADCA) at the address and phone number in the information section located at the end of this guidance. Do not assume that all duct cleaning service providers are equally knowledgeable and responsible. Talk to at least three different service providers and get written estimates before deciding whether to have your ducts cleaned. When the service providers come to your home, ask them to show you the contamination that would justify having your ducts cleaned.
#3 The ONLY time Duct cleaning is needed is when the home had a fire, Bad roof leak on to FIBERGLASS ductwork or house sat vacant for many years with out the air running. And its better to replace than to do “abrasive” duct cleaning. If the duct cleaning has a rotating brush it will remove part of the glue that is holding the Fiberglass in the ducts together, PERIOD no matter how much the say it don’t because the brush is soft.
How exactly do you expect to kill or remove mold without it ? You can’t even clean your hvac systems coils without moisture of some type ,if you use a steam cleaner you can literally clean the whole system minus the electronics . You should do more research and possibly talk to people who do the work before posting , but don’t listen to me i only have a class A contractor license ,epa license , install /repair hvacs , rent and flip houses for a living .
Some research suggests that cleaning heating and cooling system components (e.g., cooling coils, fans and heat exchangers) may improve the efficiency of your system, resulting in a longer operating life, as well as some energy and maintenance cost savings. However, little evidence exists that cleaning only the ducts will improve the efficiency of the system.