In the age of education informationization, flipped classroom in blended learning is an effective teaching model. This paper proposes that the flipped classroom teaching model in HVAC course is composed of three links before class and five links in class. It introduces the teaching designs of flipped classroom in Air Conditioning course, which includes before-class tasks of analysis of students, teaching objectives setting and motivation boosting, highly structured class activities design, as well as diversified and impartial evaluation modes and rubrics. The teaching design methods and implementation strategies proposed in this paper provide theoretical reference for teaching reform of relative courses.