Natural ventilation is a way to reduce the energy consumption of building operations and improve the indoor living environment comfort. The venturi cap is designed with a roof, grille and wind deflector to intensify the natural ventilation of buildings. The structural parameters of the venturi cap were designed using an orthogonal design. Fluid analysis software was used for numerical simulation, and variance analysis was used to study the importance of seven influence factors: the width of the roof opening, the roof slope, the height of the wind deflector, the horizontal width of the wind deflector, the angle of the wind deflector, the angle of the grille, and the spacing of the grille slices. The results show that the most significant influencing factor is the width of the roof opening, while significant influence factors include the angle of the grille and the horizontal width of the wind deflector. Additionally, the optimum parameter combination for ventilation performance at the research level was put forward, with the proposed combination achieving a volume flow rate of 5.507 m³/s. The average temperature of the horizontal plane at a height of 1.2 m above the ground was 3.002 K lower than that without a venturi cap, which provides a reference for the optimization of indoor ventilation design in buildings in the Xichang area.

The Trombe wall (T-wall) system is one of the most effective systems for passive solar energy utilization technology, which is of great significance for the alleviation of the energy crisis and the protection of the environment. Taking as an example Tibetan dwellings in the Sichuan–Tibet alpine valley which have installed T-walls for heating, the effects of the length of the room (Factor A), the width of the room (Factor B), the width of the opening on the north wall of the room (Factor C), and the distance from the lower edge of the opening to the floor (Factor D) on the indoor air temperature and room energy consumption are studied by orthogonal experiment and numerical simulation. Results show that the four factors all have a significant effect on the two analysis indicators. The rankings of the factors are consistent for their impact on the two analysis indicators, as, in both cases, Factor A > Factor B > Factor C > Factor D. Therefore, the influence of room configuration cannot be ignored in the optimization of T-wall design. Additionally, the optimal parameter combination for the highest indoor temperature and low energy consumption in winter is also proposed. This research can further improve the study of T-walls, and provide a reference for the thermal environment design of buildings.