The response level of recent public health incidents in Beijing has been adjusted to secondary response. In the case of secondary response, how should the centralized air conditioning and ventilation system be managed and used? The Beijing Center for Disease Control has just formulated guidelines for the prevention and control of centralized air conditioning and ventilation systems during the New Coronary Pneumonia Epidemic (Fourth Edition), which clearly clarifies the isolation of medical observation sites, overseas personnel diversion sites, airports, and train stations based on the current epidemic situation in Beijing , Subways, large wholesale markets, commercial complexes and other places with complex personnel structure and high mobility, as well as all kinds of sites in medium and high-risk areas, need to meet one of the following requirements, and the centralized air conditioning and ventilation system can be used:
1. The centralized air conditioning and ventilation system in all-air mode should be closed and the return air system should be operated with brand new wind. The premises (buildings) to which the central air conditioning and ventilation system belongs should be operated for an additional hour before or after being turned off every day;
2. The air-water centralized air conditioning and ventilation system must ensure that each room is independently ventilated;
3. The centralized air conditioning and ventilation system that has been equipped with air purification and disinfection devices (removing particulate matter, gaseous pollutants and microorganisms) should strictly follow the product instructions during operation to ensure that the operation effect meets the requirements of national health standards.
The disease control department proposed in the newly formulated guidelines that before using the centralized air conditioning and ventilation system, the air conditioning and ventilation system operation management department should understand the type of centralized air conditioning and ventilation system, the air supply range, the fresh air intake and other conditions. The filters, tuyere, air handling unit, surface cooler, heater (wet), condensate tray and other equipment and components of the centralized air conditioning ventilation system in operation shall be regularly cleaned, disinfected or replaced.
When the confirmed and suspected cases of new coronavirus pneumonia are found, the centralized air conditioning and ventilation systems corresponding to the active areas of the confirmed and suspected cases should be shut down immediately; the centralized air conditioning and ventilation systems in the above areas should be immediately cleaned and disinfected.
Attention should also be paid to the use of centralized air conditioning and ventilation systems: the use of centralized air conditioning and ventilation systems should ensure that all rooms in the building have air circulation and sufficient fresh air supply. During the epidemic period, natural permitting should be used to open windows to allow natural ventilation, and if possible, open exhaust devices such as exhaust fans to enhance indoor air flow. Chlorine-containing disinfectants are corrosive to metals. It is recommended to prefer quaternary ammonium salt disinfectants to metal parts that need to be disinfected.