Hygienic Evaluation of the Central Air Conditioning and Ventilation System of an Institution

Objective To investigate the hygienic quality of the central air conditioning and ventilation system in an institution, and to provide a basis for operation safety management.

Methods According to the Hygienic Specification of Central Air Conditioning and Ventilation System in Public Buildings (WS 394-2012) and the Hygienic Management Regulations for Central Air Conditioning and Ventilation System (DB 11/485-2011), samples from the central air conditioning and ventilation system in the institution were collected and measured on site.

Results The pass rate of PM_2.5 was 75% in the air outlets of the system. The count of bacteria failed to reach the standard in any air outlet. The indicators meeting the hygienic standard included PM₁₀ and fungus count in the air outlets, and dust deposition, bacterial count, and fungus count in the duct, as well as Legionella pneumophila in the cooling water.

Conclusion There is some extent of contamination and hidden hygienic trouble in the central air conditioning and ventilation system of the institution. Cleaning and disinfection of the system should be strengthened.