Building Physics and Building Services (建筑物理与建筑设备)
建筑物理与建筑设备 covers what the user feels but never sees: thermal performance, acoustics, daylight, and the water, air and fire systems. Numerical questions come from a small set of formulas and limits.
Thermal and energy
- Thermal resistance R = d/λ for each layer; the assembly value adds surface resistances Ri = 0.11 and Re = 0.04 m²·K/W, and K = 1/(Ri + ΣR + Re).
- 体形系数 S = 外表面积 / 体积; the more compact the form, the lower S and the lower the heat loss.
- 窗墙面积比 is calculated per orientation, and the north façade carries the strictest limit.
Acoustics and daylight
- Airborne sound uses the 计权隔声量 Rw (dB); impact sound uses 计权归一化撞击声压级 Ln,w - a floor can pass one and fail the other.
- 吸声 reduces reverberation inside a room; 隔声 stops transmission between rooms. They are different materials and different questions.
- 采光系数 standard values apply to side-lit rooms; 住宅 卧室、起居室、厨房 need a 窗地面积比 of at least 1/7.
Services and fire
- 消防电梯 前室 ≥6 m² alone, ≥10 m² when shared with a 防烟楼梯间; the lift must stop at every floor.
- 室内消火栓 栓口 1.10 m above the floor, positioned so two jets reach any point.
- 生活饮用水 pipework may not be directly connected to non-potable systems; backflow protection is required.
- 排烟 removes smoke from a space, 防烟 keeps it out of stairs and lobbies - one cannot substitute for the other.
Worked example: a 3.3 × 4.5 m bedroom has 14.85 m² floor area. At the 1/7 窗地比 limit the glazing must be at least 14.85/7 = 2.12 m². A 1.5 × 1.5 m window gives 2.25 m² and passes; a 1.2 × 1.5 m window gives 1.80 m² and fails, however good the daylight looks on the drawing.
Traps
- Reporting 热阻 when the question asks for 传热系数, or forgetting surface resistances.
- Averaging 窗墙比 across all façades instead of per orientation.
- Confusing 吸声 with 隔声.
- Quoting 消防电梯 前室 6 m² for a shared 前室, which needs 10 m².