The Importance of Keeping Air Conditioning Ducts Clean

It is commonly recognised that to achieve safe, comfortable and efficient working conditions inside a building, there needs to be a supply of clean and fresh air. Conversely, the presence of contaminated air is a common cause of Sick Building Syndrome.

According to environmental health experts such as the US Environmental Protection Agency, Sick Building Syndrome is often linked to poor indoor air quality which may result from biological contamination, such as bacteria, moulds, pollen, and viruses that may breed in air ducts, humidifiers and drain pans.

Inevitably all air duct systems become fouled over a period of time. The rate and severity of contamination can be attributed to a number of factors. However it is possible to deal with these issues through a sensible programme of hygiene cleaning. For example, this may be as simple as changing the filters on a regular basis.

Moreover, the Associated Code of Practice from the Health and Safety Commission in the UK requires that building ventilation systems need to be regularly and thoroughly cleaned and maintained in order to ensure that they remain free from anything which may contaminate the incoming air.

Consequently, in order to maintain a clean air supply, it is essential that the air ducting in your heating, ventilation and air conditioning system (HVAC) are all cleaned through a regular programme of air duct maintenance.

There are now a large number of reputable companies that specialise in air duct cleaning. Some cleaning companies are equipped to address the residential market, whilst other companies are primarily able to clean commercial installations. In Europe, domestic air conditioning is not particularly widespread, so most duct cleaning companies will be geared towards large-scale systems.

A specialist duct cleaning company will have access to a wide variety of extraction devices and specialised air jets and brushes specifically designed for the purpose, that enable them to remove contamination from air ducts and disinfect where necessary, depending on the design and configuration of your system.

An air duct system is generally cleaned in a particular direction aligned with the air flow, and the same is true for an extract system.

Moreover, contractors often find that existing air duct systems have insufficient access points to enable cleaning. If this is the case then they can also install access doors throughout the system to enable regular inspection, cleaning and disinfection to be properly undertaken. Once installed, the contractor will normally ensure that the location of the new access doors are captured on the client's duct plans.

Following on from the mechanical cleaning stage, the internal surfaces of the ducts are often sanitised in order to afford ongoing protection against microbial contamination developing. A sanitising emulsion is generally sprayed or atomised within the ducts so as to form a coating in the internal surfaces.

The contractor will also be able to provide formal certification that the system has been cleaned in accordance with an established standard (for example in the UK the TR/19 best-practice guide from the HVCA is widely recognised).

Moreover, a European pre-standard known as prEN 15780: 'Ventilation for buildings - Ductwork - Cleanliness of ventilation systems' is in the final stages of preparation, and is expected to be formally issued later this year (2010), and this will further strengthen the standardisation of cleaning, which can only be a good thing for facility managers.