Guardrail-based air supply terminal for improving ventilation effectiveness and saving energy in the waiting zone

In the waiting zones of airports, train stations, and other transportation hubs, poor indoor environment is primarily caused by human body-related factors in conjunction with the high density of people. Existing ventilation systems cannot effectively remove the waste heat and pollutants generated by dense crowds. In this paper, a guardrail-based air supply terminal is proposed. Two indices, the velocity target value and temperature target value, were introduced to facilitate the evaluation of the guardrail-based air supply terminal. The jet air velocity, penetration air velocity and width of the unventilated strip are optimized based on CFD numerical simulations; the values obtained were V 1  = 0.25 m/s, V 2  = 0.15 m/s, and W = 290 mm. The guardrail-based air supply terminal was found to create a homogeneous air velocity of 0.3 m/s to avoid draft sensations. The uniformity and effectiveness of the air supply via the optimized guardrails are verified by full-scale experiments and visual experiments. The temperature of the working area was maintained at 26°C in the summer, creating a comfortable environment. Compared with other existing air distribution systems in high and large spaces, the velocity target value, air age, and temperature target value with the proposed air supply terminal were the smallest. The energy consumption of the guardrail-based air supply terminal was 61% less than that of the vertical wall jets. The results indicate that the guardrail-based air supply terminal not only meets the thermal comfort requirements but also saves energy.