BEAM Plus Neighbourhood Version 1.0 Outdoor Environmental Quality (OEQ) • The thermal comfort assessment shall consider the effect of shading from the immediate surroundings, for example, trees, shading devices, self-shading from buildings; and TSI can be established using the following formula: TSI=1.7+0.1118 ×T_a+0.0019 0.0073 ×RH+0.0054 × ST [1] ×SR-0.322 ×WS- • The calculations must be based on an appropriate area breakdown in the range between 1m2 and 100m2. Where, Ta = air temperature (°C) SR = horizontal solar radiation (W/m2) WS = wind speed (m/s) RH = relatively humidity (%) ST = surrounding ground surface temperature (°C) Table OEQ1.3 Ground Roughness Value for PowerLaw Equation TSI should be based on the following: • Users shall refer to reference environmental conditions shown in Table OEQ1.2, which outlines the solar irradiation, the air temperature and the relatively humidity to assess outdoor thermal comfort; • The surrounding ground surface temperature (ST) of Air Temperature plus 3°C, (i.e. Ta + 3°C) shall be used in the TSI equation. For PET calculation, the Mean radiant temperature, Tr (Air Temperature plus 3°C, (i.e. Ta + 3°C) shall be used; Terrain Crossed by Approaching Wind n-value Sea and Open Space ~ 0.15 Suburban or medium-rise ~ 0.35 City centre or high-rise ~ 0.50 Physiological Equivalent Temperature (PET) is another well-recognised thermal index to assess thermal comfort [3]. Theoretically, PET is equivalent to the air temperature in a typical indoor setting at which heat balance of the human body is maintained, with core and skin temperatures equal to those under the conditions being assessed. • Wind environment of the Site shall adopt Computational Fluid Dynamics (CFD) technique to assess the air velocity (m/s) of the Project. The methodology of using CFD in outdoor urban scale studies shall refer to Air Ventilation Assessment (AVA) Technical Circular and Technical Guide [2]; The methodology is based on human physiological modelling and heat balance of human body, derived from the Munich Energy Balance Model for individuals (MEMI) [3]. It has been widely used for outdoor thermal study internationally, regardless of the climatic conditions, including sub-tropical and temperate climate zones. • The power n relates to the ground roughness. A larger value of the power n represents the higher roughness of the ground i.e. the dense city. Alternatively, a smaller n represents the lower ground roughness i.e. the sea surface. The ground roughness for the wind profile of the CFD simulation can be referred to Table OEQ 1.3; Table OEQ 1.4 outlines the PET range for thermal comfort in sub-tropical and temperate climates. Table OEQ 1.4 Thermal perceptions classifications for temperate region and sub-tropical region 117 Thermal Perception TPC for subtropical region [4] TPC for temperate region [5] Very cold < 14 <4 Cold ≥ 14 to < 18 ≥ 4 to < 8 Cool ≥ 18 to < 22 ≥ 8 to < 13 Slightly cool ≥ 22 to < 36 ≥ 13 to < 18 Neutral ≥ 26 to < 30 ≥ 18 to < 23 Slightly warm ≥ 30 to < 34 ≥ 23 to < 29 Warm ≥ 34 to < 38 ≥ 29 to < 35 Hot ≥ 38 to < 42 ≥ 34 to < 41 Very hot ≥ 42 ≥ 41 Copyright @ 2016 Hong Kong Green Building Council Limited. All Rights Reserved. Range of thermal comfort Too cold Range of thermal comfort Too hot

BEAM Plus Neighbourhood V1.0 - Technical Manual