During operation, dust and dirt of various origins gradually accumulate in the air ducts. The air duct cleaning is needed in three cases:

  1. The amount of dust and other solid waste has significantly reduced the inner diameter of the duct. This causes a decrease in the frequency of air changes in the room – the microclimate is deteriorating, harmful chemical compounds, dust and unpleasant odors are not removed from the room. In addition, the consumption of electrical energy by the equipment increases significantly, the motors operate at maximum loads. Valves and cut-off devices do not work, the functioning of fire detectors is disrupted. Such operating conditions cause accelerated failure of rubbing elements, due to overloads, the temperature of the stator and rotor windings exceeds the recommended values. Insulation quickly loses its dielectric properties – there are risks of short circuits. The consequence may be not only the failure of expensive electrical equipment, but also the occurrence of hotbeds of fire with all the negative consequences. Cleaning ventilation from mechanical impurities restores the initial efficiency of the system and prevents emergencies.
  2. The ventilation pipes constantly have high humidity and temperature, and these are ideal conditions for the reproduction of harmful bacteria and pathogenic microorganisms. If ventilation equipment serves food shops or kitchens, then fat settles on the walls, which is a breeding ground for them. As a result, microorganisms and bacteria are spread throughout all rooms connected to ventilation systems. In the same way, infectious viral diseases can spread during epidemics. Air filters are often the source of infection. If they are not cleaned or replaced in a timely manner, a huge number of microorganisms accumulate in them, the filters cannot contain them, and natural migration begins throughout the system.
  3. In treatment rooms to maintain the specified sterility parameters. This is especially true for operating rooms and neonatal wards. According to the order of the Ministry of Health, all hospital ventilation systems are periodically taken tests to check the microflora. If deviations are found, unscheduled work is performed. The frequency of routine cleaning and disinfection is adjusted taking into account the characteristics of hospitals.

Sanitary norms and rules establish strict requirements for the cleanliness of ventilation systems, methods of checking and analysis, frequency and cleaning methods. Failure to comply with these regulations entails administrative penalties. In cases that entail a persistent violation of human health, criminal liability may ensue.

Algorithm for maintenance and cleaning of ventilation systems

Work begins with checking the performance of the ventilation system, external and internal inspection of the air ducts.

  1. Checking the integrity of the surfaces of the ducts, the stability of the fastening of all elements of the system. The condition is visually inspected, special attention is paid to the joints and fasteners.
  2. Checking the condition of electrical equipment. If necessary, the revision of electric motors, electromechanical drives for air flow control is carried out. If there are filters, then, depending on their technical characteristics, periodic maintenance or complete replacement is performed.
  3. Removing dust and dirt from external surfaces, cleaning decorative ventilation grilles.

Maintenance of the units is carried out depending on the characteristics of the equipment and its purpose. Only trained specialists with permits are allowed to work.

Checking the standing of industrial air ducts

The long length and size of air ducts require special equipment and fixtures for testing. Inspection of internal surfaces is done with modern devices:

  • Remote manipulators with mini video cameras. Cameras are fixed to flexible cables up to 40 m long; to improve the picture, a backlight is installed on the camera. Inspection is carried out through the hatches for cleaning the air ducts, if necessary, additional holes are cut in remote areas. The technological holes made are closed after inspection. 
  • Robots. Used to diagnose the condition of large-diameter pipelines. Robots with video cameras, controlled by a remote control. 

Based on the data obtained, a map of the technical condition of the internal planes of pipelines is drawn up, the amount and nature of contamination is determined. Inspection data is used to determine the best way to clean ventilation systems.

For ventilation of private houses, it is not required to check their condition with special equipment. Functionality check is carried out by visual method, smoke or open flame. If the draft is insufficient or completely absent, then the system should be cleaned. In some cases, it will be necessary to dismantle pipes, it is difficult and time consuming. An economical and simple way is to clean the ventilation systems from contamination using an additional powerful fan. It is connected in parallel to the existing one or instead of it, the unit is switched on at maximum power. The strong air flow is able to remove dust from the inner surfaces of the air ducts. This method requires special training of performers, the price of services depends on the complexity and volume of work.

There are several ways to clean the air duct, the specific choice depends on the nature and amount of contamination, the size of the pipes and the place of their installation. After receiving the application, the responsible representative of the specialized company arrives at the place of work to assess their volume and draw up a plan for order fulfillment. At the same time, issues with the start and end dates of service are being resolved. The customer has the right, if necessary, to demand the repair of ventilation ducts, services must be additionally paid.

Mechanical cleaningThe most common method, effectively removes dust, cobwebs and small particles. Universal application, it can be used both on large general house or general production systems, and in retail premises or office centers. The only possible method for cleaning pipelines in sports and concert halls. For industrial air ducts of large cross-section, mechanical equipment is used to clean the ventilation. The unit consists of:

  • Movable brush. It can have a different diameter, the dimensions are selected taking into account the parameters of the pipes. The drive can be carried out by pneumatic or electric motors.
  • Powerful fan. It is connected to the air duct in the direction of the brush movement. When cleaning the ventilation ducts, a lot of dust is generated, the fans remove it.
  • A set of filters. It consists of filters for coarse and fine cleaning, retains dust in special accumulators, prevents it from entering the room.

There are various equipment for cleaning ventilation in terms of power, length of the brush control cable, technical parameters of fans and filters. Rotating brushes clean both round and square or rectangular air ducts efficiently . Brushes have different hardness, metal can be used for industrial ventilation. The shaft rotation speed ranges from 300 to 600 rpm.

The operator of the installation during the production of work can change the direction of rotation of the brush and make reciprocating movements. The most contaminated places are processed for an extended period of time, if necessary, a second pass is performed. The quality of cleaning can be monitored visually with video cameras. If they are absent, the pipelines are cleaned until dust ceases to enter the filters. 

The brush can clean up to 30 meters of pipelines in one pass. If the distance between inspection or technological hatches exceeds these values, then additional holes are made. After cleaning the ventilation systems, they are hermetically sealed. To seal the gaps, rubber gaskets for the diameter of the hole or various sealants can be used, the hatches are fixed to the pipes with clamps of the appropriate size and geometry.

Chemical cleaning A more sophisticated method, used to remove fatty deposits. Household systems are cleaned with flexible shafts with brushes, driven by an electric drill. 

A foam roller moistened with special detergents is attached to the brush. If the dirt is thick, then the operations must be repeated several times.

Chemical reagents can be sprayed into air duct sections; liquids contain surfactants that react with fats and release them into easily removable fractions. Fat lags behind the walls and can be easily removed by ordinary means.

Important. After cleaning the ventilation ducts with chemicals, the room must be carefully checked.

Cleaning of interior surfaces with “dry ice”

An innovative method, cleaning is carried out with dry reagents in powder form. They move along the entire length of the air duct with an air stream; when in contact with fat deposits, a controlled explosive reaction occurs. As a result, the plaque lags behind the walls and breaks down into microparticles, which are removed from the system by an air stream.

The method has proven effective in cleaning ventilation systems in food processing shops. It makes it possible to carry out work without shutting down ventilation – the production process is not disrupted, direct costs and possible losses are minimized. After cleaning, quality control is carried out using video cameras; there is a need – repeated cleaning with dry ice or other methods are applied.

Disinfection of systems The decision is taken by the sanitary station or other bodies of state supervision. It is necessary in case of the appearance of pathogenic microorganisms or pathogenic bacteria. Disinfectants are selected taking into account laboratory tests.

For disinfection, specialized companies are involved with equipment and work experience. Disinfectants are sprayed directly into the air ducts. The concentration is calculated in advance. Air currents carry the active ingredient throughout the entire duct. During work, use respiratory protection. At the finishing stage, the premises are actively ventilated.

The cleaning filters are most thoroughly cleaned and disinfected, in these places the maximum number of microorganisms accumulates. In some cases, these aggregates need to be disassembled and each element processed separately. In the houses of the old building, sewer systems were also installed cast-iron pipes, for their maintenance, cast-iron cleaners were installed. At present, this technology is considered outdated; engineering systems are mounted only from plastic pipes.

After completing a set of special measures, an act of completed work is drawn up and signed by the parties. It indicates the specific method by which the ventilation systems were cleaned, the detergents and disinfectants used. The preliminary price is agreed with the customers at the stage of signing the contract.