Air duct cleaning is the process of removing dirt and debris from the heating and/or cooling ducts in a home. This can become necessary with normal use of a home HVAC system but can be minimized with the use of higher quality air filters. This guide will assist you in deciding if your HVAC duct system needs cleaning as well as providing you the knowledge to hire a professional to do the job. Is this a DIY project? Although it is possible for the average homeowner to partially clean their HVAC system with a vacuum sweeper, it is better to hire a professional. A professional that is a member of NADCA (the National Air Duct Cleaners Association) is recommended to ensure that the contaminants from the ducts are not released into the home during the cleaning process.
There are two basic times when air duct cleaning is recommended. The first is when the heating/cooling equipment is replaced. This is the perfect time to get the system cleaned and to install an upgraded filter system to keep it clean. The second time to consider having the ducts cleaned is when the ducts are dirty as determined by a visual inspection. Some signs that you may want to consider it are when you see dirt in the supply registers or when the family has allergies that seem to be "acting up".
There are three generally accepted methods. The first way is called the contact method and is simply using a conventional vacuum sweeper with a HEPA filter to suck the dirt and debris out of the ducts. This method requires more and larger openings in the duct and is more likely to let the contaminants get into the home. The second method is called the air sweep method. In this process, compressed air is introduced into the duct system using a skipper nozzle to loosen debris. A vacuum (either portable or truck mounted) is attached to the system to pull the debris out of the ducts. The final method is using a rotary brush to sweep the debris off of the walls and out of the ducts. Once again, a vacuum is attached to catch the contaminants.
The simple answer is no and they are not generally considered to be a part of a professional duct cleaning service. Although a sanitizer can provide a fresh smell for awhile, there is not a lasting benefit. The EPA does not allow the use of a biocide on insulated ducts and the application of a sealant to the inside of the ducts is not very effective.
Although it is common to see "special deals", the normal cost for a system cleaning is between 500 and 1000 dollars. The actual cost varies based on the size and type of the system as well as the method that is used. It is a good idea to get at least two or three quotes for the job.
A good job is one in which all areas and all HVAC equipment has been thoroughly cleaned. The best way to find out is by checking random sites in the duct system through a visual inspection. You should walk around the system and ensure that all registers and grilles have been properly reinstalled. All access holes should be patched, sealed, and insulated when necessary. It is also a good idea to look at the air conditioner coil to make sure the fins have not been bent.