Transmission of novel coronavirus-infected pneumonia can be via respiratory droplet transmission as well as contact transmission. Central air-conditioning has the potential to spread the disease. Therefore, the use of central air-conditioning should be stopped or reduced during an epidemic. Must turn on the air conditioning, should do the following: 1, before use should be on the category of air conditioning, the range of air supply, fresh air outlets, cooling pools, these and health indicators are more relevant to the content, to have an understanding, to do a good understanding. Combined with the characteristics of the building, do a comprehensive assessment to see if it can be opened in this case. 2, while turning on the exhaust fan. 3, cleaning, disinfection of air conditioning. Even split air conditioners should be cleaned regularly.4. Open windows and doors regularly to maintain indoor air circulation. Content source: Dr. Yurai