Abstract: Due to the high installation position of traditional duct air conditioners and the horizontal air outlet, when heating, the hot air floats in the upper space of the room and is difficult to reach the ground, which easily leads to the problem of "hot head and cold feet". In response to the above issues, based on the human body's comfort requirements for hot and cold air, an innovative reversible ventilation technology was proposed. This technology achieves the rotation of the fan casing through a driving mechanism. During cooling, the casing discharges cold air horizontally to the side; during heating, the casing rotates to an orientation with the outlet facing downward, thus enabling the discharge of hot air vertically downward. During cooling, the cold air is gently blown horizontally, and the cold air flow naturally settles in the room, achieving shower-type cooling. During heating, the hot air is vertically blown downward directly onto the floor, achieving warmth starting from the feet. Compared with conventional duct fans, the reversible air supply duct fan can deliver hot air to the ground more quickly. The average temperature at the human foot position increases by approximately 2.5 ℃.

Key words: Thermal comfort, Reversible air supply, Air duct machine, Otation of the fan casing, Hot air to the ground