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.
The bottom line is: no one knows. There are examples of ducts that have become badly contaminated with a variety of materials that may pose risks to your health. The duct system can serve as a means to distribute these contaminants throughout a home. In these cases, duct cleaning may make sense. However, a light amount of household dust in your air ducts is normal. Duct cleaning is not considered to be a necessary part of yearly maintenance of your heating and cooling system, which consists of regular cleaning of drain pans and heating and cooling coils, regular filter changes and yearly inspections of heating equipment. Research continues in an effort to evaluate the potential benefits of air duct cleaning.
I had them out to clean the ducts, exhaust fans, and dryer vent in my 54 year-old home yesterday.  They showed up a bit early and took their time to ensure that all the grunge was gone.  I must say...they really earned their paycheck with this place!  The father and son duo worked together to remove and clean the register covers, ream out the ducts and vents with a big furry brush/vacuum unit, and vacuum up the mess.  They stated that I had the dirtiest ducts they had encountered in 15 years, and took over two hours to tidy them up, finding nails, copper pipe and assorted detritus and emptying the vacuum bag three times in the process.  They were here over 2 1/2 hours, yet charged the fee they had quoted me on the phone, as promised.  It was not the cheapest price I have seen, but it  seemed fair to me.
The bottom line is: no one knows. There are examples of ducts that have become badly contaminated with a variety of materials that may pose risks to your health. The duct system can serve as a means to distribute these contaminants throughout a home. In these cases, duct cleaning may make sense. However, a light amount of household dust in your air ducts is normal. Duct cleaning is not considered to be a necessary part of yearly maintenance of your heating and cooling system, which consists of regular cleaning of drain pans and heating and cooling coils, regular filter changes and yearly inspections of heating equipment. Research continues in an effort to evaluate the potential benefits of air duct cleaning.

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 .


My wife and I are suffering from allergies. We have lived in this house for 37 years and just found out that the A/C ducts need to be cleaned. We had a company one and do the job, but come to find out all they cleaned was the registers and boxes. Their house was to big to go in the duct and we are still getting dust all over the place. I have been looking for a good roto brush so I can do it myself, but all I can find are companies that sell equipment for a high price. I do not want to start my own business, I just want for my wife and I to breath better and keep from getting sick / also not have to dust twice a day. Please can you help. Thank you.
My vent covers have lots of mildew. They look bad! I live in a very humid climate in a condo. The handyman here has offered to take those down, wash them, sand, & then spray paint them with a mildew resistant paint. He said that he will leave them off overnight to dry. I am wondering if this is safe to breath the AC blowing out into the open all night??. ! Guess it is better than the mildew!?
Chemical biocides are regulated by EPA under Federal pesticide law. A product must be registered by EPA for a specific use before it can be legally used for that purpose. The specific use(s) must appear on the pesticide (e.g., biocide) label, along with other important information. It is a violation of federal law to use a pesticide product in any manner inconsistent with the label directions.
We bought a short sale home buit in 1987.  The home is gross to say the least. I called last week to set the appt. up once I knew we had a close date. They called to say they were running a bit late, which happens with this type of work. They did great work, cleaned up after themselves, very nice men, cleaned all the vents,fans inside and out. I will feel much better bringing my family into a clean home now.
The renters in my rental home complained of the dryer needing 2 cycles to dry their clothes. I called out Arizona Air Duct to clean the vent. Well, $75 later the issue is not fixed. I had another company come out. They pulled out a section of the vent to show me- there's maybe half the piping still coated in lint. (I wish i could post pictures here...)

If you or someone in your family suffers from asthma or allergies, you may be considering getting your home’s heating and cooling ducts cleaned. But even if you have no special health concerns, cleaning your ducts may appeal to you at an intuitive level. After all, if your ducts are clean, all that air flowing out of your vents should come out clean, too, right?
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.
×