It is a well-known fact, that ventilation systems are installed in buildings in order to ventilate the rooms. The system is designed to supply or extract a certain amount of air to the rooms. Even with filters fitted to the system, it can not be ensured that some contaminants will come into the system. Contaminants are accumulated throughout the years, and can after several years build to a substantial amount.
The consequence is that the system may not work as designed. If the system, besides transportation of fresh air, also serves to heat/cool the rooms, it might become difficult to regulate. The accumulated dust creates a basis for bacteria and fungi. These might, within time, free themselves from the duct, and be transported into the ventilated rooms.
Blocked or heavily contaminated filters also create a basis for bacteria and fungi. The traces will over the time grow through and release on the other side of the filter. In this way they can reach the ventilated rooms. This might cause illnesses for the occupants working in the rooms.
The illnesses will show as mucous membrane inflammation, migraine, tiredness, depression etc. Poor indoor air quality does not only come from the ventilation system, but it definitely contributes to a large extent.
Ventilation systems do not only exist as comfort ventilation in offices, but are also used in the industry as suction for gases, smoke and dust. These plants are often very contaminated. Many of these plants have no direct influence on the indoor air quality due to the fact that they act as extracts. However the ducts can get blocked, and hereby cause a poor suction from the rooms.
A dirty ventilation duct creates a fire danger. Dust burns very easily, and with suction in the duct system, the fire can spread out to other parts of the building rapidly.
For all of the above and many more reasons, there is reason enough to clean the duct system regularly.
A cleaning job can be divided into 6 phases:
1. Planning meeting
2. The inspection
3. The offer
4. The cleaning
6. Follow up
1. Planning meeting: At this meeting, the problems should be clarified with the customer. The system must be inspected in order to identify any problems.
2. The inspection: The inspection serves to identify exactly where and to what extent problems exist. Often it is not enough to inspect visually, simply because it is not always possible to get into the duct. The inspection vehicle is an effective tool to get into the most distant parts of the system. For buildings which impose very strict demands on the indoor air quality, samples of the dust can be taken. These samples can be examined for their composition and the content of bacteria. After inspection and analysis it is possible to work out a proposal for the work/cleaning to be carried out.
3. The offer: Upon the inspection and proposal, it is usually possible to offer a cleaning programme. The extent and time used for a cleaning can be difficult to estimate, and may therefore be costed by the hour.
4. The cleaning: The actual cleaning is carried out upon the basis of the inspection, and in a way that is the best for the given system. It might be relevant to perform a disinfection or coating of the system after the cleaning.
5. Proving: The job is completed by examining the system together with the customer. It is recommended that a video inspection and record is made. This inspection is carried out in the same places where the first inspection was made. In this way it is possible to obtain data which can be compared.
6. Follow up: After the final delivery, a service agreement with the customer can be arranged.