Prof. Xinhua Xu mainly involves research topics on the theory and technology of active and passive heat insulation of new building envelope, building thermal and humidity characteristics, building energy conservation and utilization of renewable energy, environmental technology of confined spaces, application of artificial intelligence and big data mining, optimal control and fault diagnosis of building and air conditioning systems. He has presided over more than 60 scientific research projects including three general projects of the National Natural Science Foundation of China and one doctoral program funds. He has published more than 200 academic journal papers, including more than 100 SCI-cited papers. He has been authorized more than 20 patents and published three English monographs and two textbooks.