After realization of experiments we come to conclusion: contamination of apartment’s air by microflora from air-conditioning system is obvious fact. Only 2 from 122 split-systems (1,6%) passed through the regular cleaning of filter. Incorrect exploitations of air-conditional systems is a risks factor for population’s health. To prevent this situation, the sanitary-educational work with people, who have at home split-system, is necessary. For prevention of split-systems colonization by the condition-al-pathogenic microflora creation of effective disinfection method is necessary.