Guidelines for the Prevention and Control of Centralized Air Conditioning and Ventilation System Operation During the COVID-19 Outbreak

Source:    |      Date:2020-08-10

Source:Date:2020-08-10Hits:

  The COVID-19 is an emerging disease. These guidelines are formulated based on current understanding of the disease.

  These guidelines are applicable to the operation, management and use of centralized air conditioning and ventilation systems under Level II response during the COVID-19 outbreak.

   I.   Before using the centralized air-conditioning and ventilation system, the operation management department of the air-conditioning and ventilation system should know the type of the centralized air-conditioning and ventilation system, air supply range, fresh air intake, etc.

  II.   According to the current epidemic situation in Beijing, in centralized quarantine and medical observation sites, overseas personnel diversion sites, airports, railway stations, metros, large wholesale markets, commercial complexes and other places with complex personnel structure and high mobility, as well as medium and high risk areas, the centralized air conditioning and ventilation system can only be used after meeting one of the following requirements:

  (I)   For all-air centralized air conditioning and ventilation systems, they shall close the return air system and run with fresh air. In the place (building) to which the centralized air conditioning and ventilation system belongs, the system should run for an additional hour before or after being turned off every day;

  (II)  For the air-water centralized air-conditioning ventilation system, independent ventilation of each room must be ensured;

    (III) Centralized air-conditioning and ventilation systems that have been equipped with air purification and disinfection devices (for removing particulate matter, gaseous pollutants and microorganisms) should be operated in strict accordance with the product instructions to ensure that the operation effect meets the requirements of national health standards.

  III.  The filters, vents, air handling units, surface coolers, heaters (humidifiers), condensate pans and other equipment and components of the operating centralized air conditioning ventilation system shall be cleaned, disinfected or replaced regularly.

  IV.  When confirmed and suspected cases of COVID-19 are detected, the following prevention and control measures should be taken:

  (I)   Immediately shut down the centralized air-conditioning and ventilation system in the areas of activities for confirmed and suspected cases;

  (II)  Immediately perform mandatory cleaning and disinfection of the centralized air conditioning and ventilation system in the above-mentioned areas.

  V.   Other precautions for using centralized air conditioning and ventilation systems include:

  (I)   For use of centralized air-conditioning and ventilation systems, ensure that all rooms in the building have air circulation and sufficient fresh air supply.

  (II)  During the epidemic period, when circumstances permit, it is preferable to open the windows for natural ventilation. If conditions permit, exhaust fans and other exhaust devices can be used to enhance indoor air flow.

  (III) Chlorine-containing disinfectants are corrosive to metals, so it is recommended to choose quaternary ammonium salt disinfectants first for metal parts that need to be disinfected.

  VI.  Disinfection methods

  (I)   Filters

  The filters should be cleaned before being disinfected. The filters can be disinfected by spaying or wiping with quaternary ammonium salt disinfectants or 500mg/L chlorine disinfectants.

  (II)  Vents and air handling units

  The vents and air handling units should be cleaned before being disinfected. They can be disinfected by wiping with chemical disinfectants. For metal parts, quaternary ammonium salt disinfectants are preferred, which shall be used according to the concentration specified in the instructions for surface disinfection. For non-metal parts, 500mg/L chlorine disinfectants are preferred.

  (III)  Surface coolers and heaters (humidifiers)

  The surface coolers and heaters should be cleaned before being disinfected. They can be disinfected by spaying or wiping with quaternary ammonium salt disinfectants, and disinfected according to the concentration specified in the instructions for surface disinfection.

  (IV)  Concentrate pans

  The concentrate pans should be cleaned before being disinfected. They can be disinfected by spaying or wiping with quaternary ammonium salt disinfectants, and disinfected according to the concentration specified in the instructions for surface disinfection.

  (V)  Air ducts

  The air ducts should be cleaned before being disinfected. They can be disinfected by spraying with chemical disinfectants. For metal walls, quaternary ammonium salt disinfectants are preferred, which shall be used according to the concentration specified in the instructions for surface disinfection. For non-metal walls, 500mg/L chlorine disinfectants are preferred.