Moisture can enter the duct system through leaks or if the system has been improperly installed or serviced. Research suggests that condensation (which occurs when a surface temperature is lower than the dew point temperature of the surrounding air) on or near cooling coils of air conditioning units is a major factor in moisture contamination of the system. The presence of condensation or high relative humidity is an important indicator of the potential for mold growth on any type of duct. Controlling moisture can often be difficult, but here are some steps you can take:

If not properly installed, maintained and operated, these components may become contaminated with particles of dust, pollen or other debris. If moisture is present, the potential for microbiological growth (e.g., mold) is increased and spores from such growth may be released into the home's living space. Some of these contaminants may cause allergic reactions or other symptoms in people if they are exposed to them. If you decide to have your heating and cooling system cleaned, it is important to make sure the service provider agrees to clean all components of the system and is qualified to do so. Failure to clean a component of a contaminated system can result in re-contamination of the entire system, thus negating any potential benefits. Methods of duct cleaning vary, although standards have been established by industry associations concerned with air duct cleaning. Typically, a service provider will use specialized tools to dislodge dirt and other debris in ducts, then vacuum them out with a high-powered vacuum cleaner.


But we don’t recommend hiring a duct cleaner to perform these tasks; too many don’t really know what they’re doing, according to the ratings of duct-cleaning outfits we have collected from local consumers. Consider hiring a top-notch heating and air-conditioning contractor to do this type of work, or pay them to do it during their next service visit. Readers can access Checkbook’s HVAC company ratings through Feb. 28 at Checkbook.org/washingtonpost/ducts.
I was hesitant to have him do that for the price he quoted me. It would have been an extra $275+ for additional cleaning!! I certainly wasn't prepared for that, so I declined the offer.  After his assistant started to use the shop vac to get some debris out of the vents, he came back in and said he was just on the phone with the office and he can lower the price of the additional service for me.  He wrote up an estimate for me and said that I could call him if I'd like to do the service.
I own a small mechanical company. My main work is service and system replacements. I have never been a believer in duct cleaning. The company I worked for before had our duct man come out and do my house. I saw no difference. Preventive maintance is what I recomend. Remove fan and clean, seal fan compartment to prevent dust from being pulled in, filters I install media filters, they are 5″ thick and pleated. I have tested them to make sure static presure was not a issue. Heat exchangers and AC coils need to be cleaned. I will tell you this to do a good cleaning I usually spent 1-2 hrs, When I’m finished I would not have a problem eating my diner on the system. Good filters, clean system and properly tuned up are my recomdation to anyone. I’ve included my email feel free to contact me with any questions. winkcfd@yahoo.com

I have worked cleaning HVAC in my area for almost 5 years. I always do a thorough inspection and cleaning, providing before and after photos. I have completed some jobs where I felt that it was not entirely necessary, but ultimately what the customer wanted. With that being said, I have endless photos of unspeakable horrors. Hotels are usually nasty, post construction mess is certain, pets and kids create lots off debris, bugs congregate and die, then spiders set up and die, I have even had one supply that was nearly plugged with sand!

If you are replacing your air conditioning system, make sure that the unit is the proper size for your needs and that all ducts are sealed at the joints. A unit that is too big will cycle on and off frequently, resulting in poor moisture removal, particularly in areas with high humidity. Also make sure that your new system is designed to manage condensation effectively.


Duct cleaning has never been shown to actually prevent health problems. Neither do studies conclusively demonstrate that particle (e.g., dust) levels in homes increase because of dirty air ducts or go down after cleaning. This is because much of the dirt that may accumulate inside air ducts adheres to duct surfaces and does not necessarily enter the living space. It is important to keep in mind that dirty air ducts are only one of many possible sources of particles that are present in homes. Pollutants that enter the home both from outdoors and indoor activities such as cooking, cleaning, smoking, or just moving around can cause greater exposure to contaminants than dirty air ducts. Moreover, there is no evidence that a light amount of household dust or other particulate matter in air ducts poses any risk to health.
We are a hvac company that provide air duct cleaning service are minimum charge $400 to do a proper air duct cleaning with 2 techs avg 3-6 hours that includes sanitizing. I get phone calls all day about the $99 your not going to get much of a cleaning for that price it for them to get there foot in the door and up sell that the only way for them to stay in business. Just from my 15 years of duct cleaning experience.
I recently did some remodeling and figured I’d get the air ducts cleaned in our 12 year old home. After obtaining 4 estimates between $572 and a whopping $3,075 for 25 vents and 2 air handlers, I knew I was in for a ride. I read through this blog and decided to use a $79 inspection camera I just found online (Home Depot) to take a look at all my ducts by removing the ceiling grilles first and then try to get into the ducts from the other end. From what I have just learned here, I believe that will take care of my “concerns”.

Best Air DC Air Duct Cleaning Scam! I purchased an Air Duct Cleaning from this company through Groupon. When I originally scheduled the latest cleaning it was Nov. 8, 2017. They finally showed up today March 8, 2018. When they arrived they got set up looked in the vents with there camera and said it looks like you will need an Air Duct Cleaning; we will be vacuuming today. Best Air Rep: The cleaning after looking inside will be $200-$500 additional. ??? I was floored. The next statement from the Best Air rep was: Who did your last cleaning? "They did a horrible job." What he did not realize is that they had done the last supposedly Air Duct Cleaning on May 3, 2016. So I asked him to provide me with a receipt describing the services he complete today and the pictures after they finished when he was done. He did not. I followed up with a call into the main office where I had originally made my appointment and was told I did not buy anything from them, call Groupon for a receipt and the description of the services is there as well. Unreal. Scam of all scams. So, me being the person I am I called back to give them a chance to actually come out and complete the service they told me they were doing the last couple of years. I was screemed at by the supervisor and told we are not coming back out for free. Call groupon if you want a copy of receipt and description of services. I would like a full refund of $59.00 plus what I paid this company in 2016 as well as a promise to pay from Groupon for a real company to come out and do a real Air Duct Cleaning. I would also like the false advertising from this company or any other company through Groupon or any other discount service to STOP immediately. All misleading ad's should and must be removed.


On the other hand, if family members are experiencing unusual or unexplained symptoms or illnesses that you think might be related to your home environment, you should discuss the situation with your doctor. EPA has published the following publications for guidance on identifying possible indoor air quality problems and ways to prevent or fix them.
×