In air-conditioned and ventilated areas, in addition to the temperature, flow and humidity, care must be taken about the microbiological quality of the air we breathe. Air from ventilation and air conditioning systems that are not regularly maintained is often of poor quality and sometimes of an unpleasant odor. The moist, dirty and dark places inside the ventilation and air-conditioning systems form fertile soil for the development and propagation of bacteria, molds and fungi. Exposure to bacteria, molds, fungi and other contaminants can lead to unpleasant reactions, chronic diseases and “sick building syndrome” in humans. The most common problems associated with “sick building syndrome” are irritation of the mucous membranes of the eyes, nose and throat, dryness of the mucous membranes, coughing, itching, frequent respiratory infections, headaches and psychological fatigue. And one of the most dangerous bacteria that is an ideal place to develop uncleaned ventilation and air ducts is Legionella.
Legionella growth and reproduction are affected by temperatures ranging from 25 to 44 ° C, inorganic and organic pollution, and water standing in the system. Legionnaires’ disease is caused by Legionella bacteria. Humans become infected by inhaling the air in which the bacterium is found. After an incubation of 2 to 10 days, it causes atypical pneumonia, of which 15 to 20 percent of patients die.
Legionnaires’ disease is an atypical pneumonia named after American legionnaires who, at a rally in a hotel in Philadelphia in 1976, have contracted since then unknown, lethal, some deadly diseases.
Doctors subsequently discovered the bacterium in the hotel’s air-conditioning system.
The main cause of poor air quality in air-conditioned rooms is poor and sometimes no cleaning or maintenance of air conditioning, ventilation and air conditioning ducts.
The problem of air quality is particularly pronounced in areas where local air-conditioning systems (window units and split systems) are used. For a large number of users of air conditioners, due to ignorance, the prevailing opinion is that air conditioners should not be cleaned and disinfected, but that it is sufficient to wash the filters regularly. Only when they start to feel uncomfortable in air-conditioned rooms, when an unpleasant odor is felt from the air conditioner. Few air conditioning owners are aware of the dangers posed by dirty appliances. The need to clean the air conditioners stems from their mode of operation. With split systems, window units and fan coils, the turbine-fan draws air from the room. As a rule, this air is contaminated with dirt and microorganisms. Most of the dirt and microorganisms are retained on the filters and therefore need to be regularly cleaned and disinfected, and regularly replaced with a fan convector. After filtration, the air passes over the heat exchanger where it cools. The part of the dirt and microorganisms that is not left behind on the filters is retained on the exchanger. It creates insulating layers and creates bio-film (accumulation of microorganisms). To remove the insulating film and bio-film from the exchanger, it must be thoroughly washed and then disinfected. In addition to the air being cooled on the exchanger, it is condensed by moisture from the air. The condensate is poured down the inverter blades into the drain pan and drained out. Humidifier fins and drain pan are a good place to grow bacteria, molds and fungi. Due to the possibility of bacteria, molds and fungi, special attention should be paid to maintaining the drainage pan. If it is not kept clean and if it is not disinfected regularly, the drainage pan can become a source of various allergies, diseases and odors.