Duct cleaning is a chore that most people forget about until the performance of the central heating system or air-conditioning unit drops. Duct cleaning is a job that does not need performing frequently, but it is good practice to clean out the system at least every two years, preventing a build up of dust and detritus. Most air-conditioning units and central heating systems should be tested by professionals regularly, so you can incorporate a duct cleaning regime into the maintenance schedule.

Ducts are prone to a number of potential problems, and a build up of trapped dust, debris and detritus will seriously impair efficient operation. Blocked ducts carry potential health risks, especially to people with respiratory ailments, and the unit will need to work much harder, adding to the electricity bill. Regular duct cleaning makes financial sense and you will recoup most of the cost through lower bills.

As an example, the seals on the ducts will fail, over time, and the system will start to suck in airborne dust and pollutants, blocking the ducts and impairing operation. The ducts may develop splits and holes, sending particulate contaminants into the atmosphere of the building, which can trigger severe respiratory problems. This dust is often laden with harmful microbes and fungal spores, with the potential for causing serious illness. In a city environment, this dust will include noxious pollutants emitted from vehicle exhausts, and these are the last thing that you want circulating around a building.

Depending upon the complexity and the exact layout of your ducting system, there are three types of duct cleaning. The negative duct cleaning method uses powerful vacuum cleaning attachments to suck out the majority of the accumulated dust and detritus. If your ducts are lightly soiled, and are fairly short and straight, vacuum duct cleaning is an excellent choice. The only downside is that the operative may have to cut a hole in the duct to fit the nozzle, although the contractor will repair this before leaving.

For heavily soiled ducts that have not been cleaned for many years, it may be better to use the brush duct cleaning option. The operative uses rotary brush attachments to physically scour and clean the ducts, often using a vacuum to extract the disturbed dust. The brush duct cleaning method is much more expensive, but may be the only option for long lengths of duct, ensuring that any awkward spots will be cleaned thoroughly, preventing dust from building up in ‘dead zones’ and corners.

For people with hypersensitivity to pollutants and pathogens, or with severe respiratory conditions, the only safe solution may be dismantling the entire duct system and cleaning each section individually. This process is extremely tortuous and expensive, but it is the only way of ensuring complete cleanliness. This process is only necessary in the worst cases and, once completed, regular negative duct cleaning should be sufficient to maintain the ducts.

When trying to find a reputable duct cleaning system, take your time in finding the best contractor for the job, and ask at least three companies for quotes. You should check that the company is fully insured and properly licensed, protecting you if anything goes wrong. The figures quoted should all be in the same ballpark so, if a contractor quotes you an extremely low price, the alarm bells should start ringing. Either they are an inexperienced new contractor, looking to break into the market or they are cutting corners somewhere, so you should be very wary. There are many unscrupulous companies out there, basically trying to scam homeowners, so look at the fine print of any advertisment and remember one simple rule.

If it sounds too good to be true, it probably is.

Some of the questions that you can ask:

• How much does it cost? Expect to pay at least 400 dollars for a medium sized house, more if your system is complex. Ask for a full quote in writing.
• How long will it take? The process should take an entire morning or afternoon, hence the high cost.
• Are you NADCA certified? A reputable air duct cleaner should have this certificate, as a minimum.
• Do you provide before and after photos? This will allow you to see that the contractor cleans the entire duct, not just the first few feet.
  

Be thorough in your research, ask for references and make sure that you follow them up. Large, national companies are often much cheaper than local contractors, a local but the local duct cleaning company relies upon a strong reputation and word of mouth marketing, and cannot afford to attract bad publicity. As a result, local duct cleaners are often a safer option, providing personalized and efficient duct cleaning services, even if it does cost a little more. If, at any stage, you have any misgivings or gut feelings, walk away, despite the hard sell.