How to properly use central air conditioning during the epidemic Just read this one

How to properly use central air conditioning during the epidemic Just read this one

The National Health Commission’s official WeChat "Healthy China" released the "New Coronavirus Science Knowledge" on February 9th, showing that at present, the main route of transmission of the new coronavirus is respiratory droplet transmission and contact transmission, aerosol and fecal-oral The transmission route has yet to be further clarified. Under the epidemic situation, rework is imminent, will all units cause the spread of new coronary pneumonia when they turn on the central air conditioning? If so, how should the central air-conditioning be used correctly in the office building to avoid risks? How does the property unit conduct safety management of central air-conditioning? What are the precautions when using household central air conditioners? In response to these issues that the people are most concerned about, Xinhuanet invited Xu Wei, Dean of the Institute of Building Environment and Energy Conservation, China Academy of Building Research, Professor Li Xianting of Tsinghua University, Li Jianhui, Vice President of the China Association of Materials and Directors of the Facilities and Equipment Technical Committee, and China State Construction Engineering Liu Peng, deputy chief engineer of the Design and Research Institute, and Meng Qingguo, secretary-general of the Chinese Society of Refrigeration, provided scientific answers.

　　 Xinhuanet: At the moment of the epidemic, is there a risk of cross-infection in central air conditioners? How do units reduce the risk of using central air-conditioning?

　　 Xu Wei: The prevention and control of the new crown pneumonia epidemic is currently the most important work. The correct operation of the air conditioning and ventilation system during the epidemic period of infectious diseases can effectively reduce the chance of cross infection. Due to the diverse types of buildings and the wide variety of central air conditioners, in an environment with the possibility of cross infection, three common suggestions can be put forward: First, use fresh air from the air conditioner as much as possible, increase the amount of fresh air, and open windows conditionally Windows can be opened regularly for ventilation, which is helpful to prevent the spread of the epidemic; second, for buildings that do not have fresh air conditions, in order to prevent cross-infection, it is necessary to add medium-efficiency and sub-high-efficiency filters, which can effectively remove fine particles in the air; third, If the first two suggestions cannot be realized, it is recommended to avoid using central air-conditioning and use local heating.

Li Xianting: At the moment of the epidemic, in order to avoid cross-infection, the use of central air conditioners that share return air in multiple rooms needs to increase the fresh air volume while turning off the return air; for central air-conditioning systems that cannot increase the fresh air volume and must use return air, they should Try to use filters above F7 in the air conditioning unit or return air outlet; considering that most areas of the country are still in the heating period, increase the fresh air volume while maintaining the indoor temperature to maintain the basic comfort requirements of the human body.

　　 For buildings without fresh air system or insufficient fresh air volume, it is recommended to open windows regularly for ventilation, and turn on the exhaust system when conditions permit. A room that has neither a fresh air system nor a ventilation system and cannot open windows for ventilation has a greater risk of cross-infection and should be avoided during special periods.

Xu Wei: It should also be emphasized that the above recommendations do not include hospitals and buildings with confirmed cases. Because the situation in hospitals is more complicated, personal protection must be done. Once confirmed cases are found in other buildings, the central air-conditioning system should be turned off in time. And carry out elimination and isolation work.

　　Xinhuanet: In response to the epidemic, can you tell us what work related units in the industry have done?

Xu Wei: Based on the valuable experience during the prevention and control of the SARS epidemic in 2003, the Chinese Academy of Building Research and the Environmental and Health Related Product Safety Institute of the Chinese Centers for Disease Control and Prevention jointly compiled the national standard GB50365-2005 "Ventilation and Air Conditioning System Operation Management Regulations", which is the first Chapter Five formulated emergency management measures specifically for emergencies, and the standard was revised in 2019.

　　 The spread of the new crown pneumonia epidemic and SARS are basically the same, so the central air-conditioning response measures are not essentially different from the previous ones, but higher requirements are put forward. On February 1, the Institute of Building Environment and Energy Conservation of the Chinese Academy of Building Research launched the "Guidelines for the Operation and Management of Public Building Air-conditioning and Ventilation Systems during the Epidemic Period", which is applicable to office buildings and other buildings such as hotels, schools, hospitals, and transportation hubs with the same function. It can be implemented by reference, and different functional parts need to be added or supplemented according to the use of functions.

Li Jianhui: The Facility and Equipment Technical Committee of the China Property Management Association and the China Academy of Building Research, according to the national standard GB50365 "Air-conditioning and Ventilation System Operation Management Standards", organized some professionals in the air-conditioning system of the property management industry, together with experts from the China Academy of Building Sciences, in 2 On March 3, the "Technical Guidelines for the Operation and Management of Air Conditioning and Ventilation Systems in Public Buildings During the Epidemic Period (Trial)" was jointly issued in time to guide the safe operation of air conditioning and ventilation systems in various public buildings during the epidemic prevention and control period. Since then, the China Property Management Association has successively issued the "Operational Guidelines for the Prevention and Control of New Coronary Pneumonia in the Property Management Area of ​​Colleges and Universities" and the "Operational Guidelines for the Prevention and Control of the New Coronary Pneumonia in the Property Management Area of Industrial Parks."

Liu Peng: Considering that the management of many office building property companies will face shortcomings after rework, China Construction Technology Group organized and compiled the "Guidelines for Emergency Measures for the Operation, Management and Use of Office Buildings". In the three directions of system, water supply and drainage system, daily disinfection, and garbage collection and temporary storage, concise and practical implementation measures are given to cut off pollution sources and transmission paths.

　　 Meng Qingguo: On February 3, the Chinese Society of Refrigeration, together with well-known experts and scholars in the industry, jointly compiled the "Recommendations for the Safe Use of Air Conditioning (Heating) After the Spring Festival" in Response to the New Coronary Pneumonia Epidemic, which was officially released and reported to the China Association for Science and Technology. In the follow-up, we will also do a good job in industry services through the establishment of a WeChat group of experts, the establishment of a dedicated telephone line, and the submission of special reports to the China Association for Science and Technology.

Xinhuanet: Zhang Liubo, chief disinfection expert of the China Centers for Disease Control and Prevention, and director of the disinfection center of the Environmental Institute, suggested that the central air conditioner should have an understanding of the type of air conditioner, the range of air supply, the intake of fresh air, the cooling pool and the sanitary indicators before use. If you know it, you should make a comprehensive assessment based on the characteristics of the building. Excuse me, which department should be responsible for the above specific operations? How to implement specific work on the safe use of office buildings?

Li Jianhui: In government office buildings, office buildings, hotels, shopping malls and other public buildings, the operation of air-conditioning and ventilation systems accelerates the flow of air in various areas and between floors. In areas with high population density, long use time, and relatively closed indoors In the region, there is a greater risk of cross-infection. Safe, scientific and reasonable operation of the air conditioning and ventilation system to prevent the spread of the new coronavirus caused by the air circulation caused by the air conditioning and ventilation system, and to protect the health of the people in the building to the greatest extent, is one of the important responsibilities of the facility equipment operation manager .

In addition to the published operational guidelines for the prevention and control of the new crown pneumonia epidemic in different types of construction areas, the China Property Association requires all property service companies to increase their attention to the new crown pneumonia epidemic and strengthen the entrance and exit of buildings and underground parking lots. At the same time as the physical defense of relatively densely populated areas, it is required to assign special personnel to be responsible for the air-conditioning system, elevator system and other equipment.

According to the recommendations of air-conditioning and ventilation system experts, when the air-conditioning system is put into use in a building where no epidemic has occurred, the air-conditioning unit should be operated under fresh air conditions. In principle, the per capita fresh air volume should not be less than 30 cubic meters per hour, and air conditioning should be added. The cleaning and disinfection frequency of key equipment such as the internal filter, surface cooler and fan coil return air filter of the unit, it is recommended that the transportation system be cleaned and disinfected according to the actual flow of people, and office buildings and other areas should be cleaned and disinfected regularly or daily as appropriate .

During the epidemic period, the air conditioning and ventilation systems of public buildings should be put into operation and preheating 1-2 hours before use. After use, the fresh air and exhaust systems should continue to operate for one hour to fully ventilate the buildings to ensure indoor air. Fresh. When conditions permit, consider adding an appropriate amount of simple air showers to each personnel entrance or elevator entrance, etc., and temporary disinfection facilities such as ultraviolet disinfection lamps can also be installed to disinfect the area during non-use time.

　　 Liu Peng: Under the epidemic, in order to ensure safe and orderly work, the safety issues of the office building's water supply and drainage system and the temporary storage of garbage collection are also critical. The water supply and drainage system includes tap water, hot water and sewage. From the perspective of sanitation and epidemic prevention, tap water requires water quality testing in accordance with regulations, hot water requires disinfection of low-temperature pipes, and sewage systems require water sealing and airtight work. The property should confirm whether the water seal is one by one. If it is available and effective, it will be blocked if it is uncertain. The office building should also strengthen the disinfection of key parts and daily disinfection. In terms of garbage collection and temporary storage, the property is required to operate in strict accordance with the rules and regulations, with a dedicated person in charge, and to collect used masks separately.

　　 Xinhuanet: During the epidemic, can household central air conditioners be used normally? What are the precautions for users in use?

　　 Xu Wei: In the residence, without confirmed cases, suspected cases, and close contact with them, the home central air-conditioning should be able to operate normally, just pay attention to open windows for ventilation, frequent hand washing and necessary disinfection.

　　 Li Xianting: Compared with public buildings, the design of household central air-conditioning systems is relatively simple, and families do not affect each other. If there is no potential infected person in a family, it can be used normally. If a family member is a suspected case and needs to be properly isolated for observation, it is recommended that the quarantined person live in a room with exhaust function. Relatively speaking, this can ensure that the wind in the family flows from other rooms to the room, and minimizes the family Internal cross infection. It should also be noted that based on the experience of Hong Kong Amoy Gardens during the SARS period, residents should pay attention to maintenance when using water pipes and floor drains. The water seals and floor drains should be sealed to minimize the risk of cross-infection between different floors.

　　 Liu Peng: First of all, all water seals in the home must be sealed, including washbasin drains, floor drains, shower drains, bathtub drains, sink drains, and washing machine drains. The user needs to check whether all the drain pipes have traps. For the bathtub and washing machine, it is not easy to determine the trap status. It is recommended to plug the bathtub drain when not in use, pull out the drain hose of the washing machine, and connect it when it is used. Check whether the floor drain in your home is airtight, especially to clean the hair in the bathroom floor drain. If you cannot determine the depth of the water seal, you can plug the floor drain with a plastic bag filled with water. Some water can be seen in the bottom of the toilet, and the drain pipe must be submerged when it is stored horizontally, and it should be noted that no bubbles in the water can emerge. In both cases, it needs to be repaired in time. Second, wash your hands frequently at home and disinfect sanitary appliances frequently.

　　 Xinhuanet: During the epidemic, what specific suggestions do you have for the majority of upstream and downstream central air-conditioning companies?

　　 Li Xianting: First of all, in order to reduce the risk of cross-infection during the epidemic, some buildings have put forward central air-conditioning transformation requirements. This puts forward new requirements for the product design and improvement of central air-conditioning enterprises, and can bring new opportunities for industrial development.

Secondly, from the perspective of the central air-conditioning industry itself, we should focus on solving problems that have not been solved before, such as how the central air-conditioning system can better adapt to needs and protect better in special environments such as designated hospitals and rebuilt shelter hospitals. Medical staff, etc.

　　 Third, many buildings attach importance to indoor temperature protection rather than ventilation systems. From the perspective of hygiene and epidemic prevention, the priority of ventilation should be higher than room temperature protection. The indoor temperature must meet the demand while ensuring ventilation. The epidemic will prompt the entire industry to think about new requirements for comfortable and healthy central air-conditioning products, design and operation.

Xu Wei: Air-conditioning operation companies should actively cooperate with owners to operate and maintain scientifically in accordance with relevant guidelines to ensure the health and safety of personnel in buildings. Designers of central air-conditioning systems should actively consider and summarize the new problems, new requirements and requirements brought about by this epidemic. New measures to improve and upgrade relevant standards to better protect people’s health and respond to emergencies.