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Air Humidifiers / Air WashersAn air humidifier cleaner is used in water-operated air cleaners, also called air washers, and air humidification systems, that have one thing in common: they combine air, water, dirt and temperatures in a way that optimally promotes microbial growth. A particularly unpleasant aspect of this is that these germs and their metabolic products can easily become airborne, where they can be inhaled. Regular cleaning air washers and disinfection of air washers and humidifiers is therefore urgently recommended for anyone operating such devices.
An air humidifier cleaner and an air washer cleaner are used for treating these two types of devices. The difference between these two types of device lies primarily in their intended use, although there may be an overlap between humidification and air washing depending on the specific design. Humidifiers increase the water content of the air to achieve a desired level of relative humidity. This is necessary, for example, to prevent electrostatic charges, which can cause damage in certain industries, such as printing works or electronic component manufacturing.
By contrast, air washers moisten the air by means of a curtain of water, whereby dust, fibres and dirt are bound and washed out by the water droplets. These air washers are used primarily in the paper, pulp, cardboard and wood industries to reduce the amount of airborne dust and to prevent the downstream filter stages from becoming caked with dust particles too quickly. However, the washed out dirt in the water can potentially serve as a food source for microorganisms and thus promote microbial contamination.
Air humidifier cleaner is important also for home use, where combined air washers / humidifiers are available with a water bath and rotating air humidifying discs. A stream of air sweeps over the damp discs and absorbs moisture. At the same time, some of the dust in the air sticks to the wet discs and ends up in the water bath. The regular addition of hygiene products for cleaning air humidifiers — and often also silver sticks — is intended to prevent rapid and severe bacterial contamination and mould formation in the water. Provided that suitable cleaning humidifier products for air washers are used, e.g. air humidifier cleaner Sanosil S015, and the dosage is correct, this can work very reliably. However, it is essential to regularly clean air humidifier and its water tank.
Traditional humidifiers, which use a heating coil, are also still in use. These generate steam by heating the water. Due to the high temperatures, these devices are insensitive to microbes and can be safely operated without adding disinfectants for air humidifiers. However, they require regular descaling (e.g. with citric acid or vinegar) and also consume significantly more power than other models. Since the danger of contamination with bacteria and mould is virtually non-existent in traditional humidifiers, they tend to be awarded above-average scores by Germany-based Stiftung Warentest and other consumer organisations in this sector.
Ultrasonic nebulisers are the third common type of humidifiers. In these devices, water is atomised into mist droplets by a vibrating plate. Usually, the water tank is emptied within only a few hours and must be topped up. This reduces the time frame in which microbes can multiply in the water. However, if operation is reduced and water is left in the tank for more than 24 hours, it is essential to add a small quantity of cleaning products for air washers like Sanosil S015 (usually at a dosage of 0.1 ml/L) to prevent microbial growth.
Ultrasonic dehumidifiers should be disinfected before each use if they have not been used for while — ideally by means of shock disinfection, in which about 7 ml of S015 air washer cleaner is added to the water and allowed to act for four hours.
Initial situation: a textile company operates an air washer to reduce the quantity of airborne textile fibres. After several employees contract pneumonia and respiratory tract infections, the cause is identified as the severely contaminated air washer system. Three or four cubic metres of water are sprayed inside this air washer daily; the water is drawn through a particle filter to remove the coarser dirt and then circulated. In the evening, the basin is drained together with the concentrated salts and dirt.
Problem: due to ignorance, no biocide is used in cleaning an air humidifier / air washer. Only hardness stabilisers are added. The entire system is overgrown with a dense biofilm; it is slimy and smells like a sour washcloth.
In the erroneous assumption that draining and replacing the dirty water each evening was sufficient to ensure hygiene, the system's operators had virtually ensured the growth of microbes.
Solution: firstly, personnel wearing protective equipment treated the air washer with an alkaline foam cleaner and used brushes to remove dirt and biofilms from its surfaces. The pipes were filled with diluted sodium hydroxide solution and then flushed. Since no calcium deposits were present due to the hardness stabilisation, it was not necessary to clean the system with diluted hydrochloric acid as an intermediate step. The cleaned surfaces were disinfected with Sanosil S010 air humidifier cleaner i.e. disinfectant solution, and the pipes were filled with disinfectant solution in a shock disinfection process.
To prevent future contamination, a continuous dosing system with Sanosil S015 was installed in the fresh water supply, which will add disinfectants for air washers to the fresh water.
Cleaning and disinfecting a heavily contaminated domestic air washer / humidifier: a case study
Initial situation: a domestic air washer/humidifier with plate humidification is operated during the winter months. The device is frequently filled with fresh water, but not cleaned for several weeks at a time. No hygiene agent or disinfectant is used. An integrated silver stick cannot prevent contamination of the air washer due to the high volume of dirt. Mould and bacterial slime are present inside the humidifier.
Several residents are suffering from severe respiratory tract irritation and exogenous allergic alveolitis — almost certainly caused by bacterial toxins in the air washer.
Solution: the device was thoroughly cleaned with detergent and treated with citric acid solution to remove the limescale deposits. All interior surfaces were thoroughly sanitised using Sanosil S003 air humidifier cleaner. The unit will be inspected regularly during future operation and a cap of Sanosil S003 disinfectant will be added to the water during each filling.
