The Israeli wind criteria (as published in the Israel Green Building Standards (SI 2581:Sustainable Building)) are required to be analyzed in the Israel region to assess pedestrian wind comfort and safety conditions in the vicinity of new and, in some circumstances, existing developments. The criteria sets out four comfort categories which are correlated to various pedestrian activities and reflects the fact that less active pursuits require more benign wind conditions. The categories are seating zones, entrances, streets & parking, in ascending order of activity level, with a further category uncomfortable for all pedestrian uses. The criteria are derived for open air conditions and assume that pedestrians will be suitably dressed for the season (thermal comfort however is not tied to this assessment). Uncomfortable conditions would not usually form part of the ‘target’ wind environment and would usually require mitigation. Mitigation applied to improve pedestrian comfort would also reduce the frequency of, or even eliminate, strong winds. The criteria are summarized below:
Wind Comfort Category | Wind Speed Calculation | Exceedance Frequency (%) for Wind Speed Thresholds | Description | |
6 m/s | 9 m/s | |||
Seating Zones | ≤ 10% | ≤ 5% | Calm or light breezes desired for outdoor restaurants and seating areas. | |
Entrances | ≤ 15% | ≤ 10% | Gentle breezes suitable for main building entrances, bus stops, and places where pedestrians may linger. | |
Streets & Parking | ≤ 20% | ≤ 10% | Moderate winds that would be appropriate for leisurely walking down streets or parking lots. | |
Uncomfortable | > 20% | > 10% | Strong winds considered a nuisance for most pedestrian activities. | |
Notes: 1. = Gust equivalent wind speed with an assumed alpha coefficient (α) of 3; 2. = Horizontal mean wind speed; 3. = Root-Mean-Square (RMS) of mean wind speed; 4. Wind conditions are considered to be comfortable for the listed comfort category if the predicted exceedance frequency is equal to or less than the 6 m/s wind speed threshold; 5. Based on an annual analysis from January through December between the hours of 0:00 - 23:00; |
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Wind Safety Rating | Wind Speed Calculation | Exceedance Frequency (%) for Wind Speed Thresholds | Description | |
15 m/s | 20 m/s | |||
Pass | ≤ 1.5% | ≤ 0.01% | Excessive gust speeds that can adversely affect a pedestrian's balance and footing. Wind mitigation is typicaly required. | |
Exceeded | > 1.5% | > 0.01% | ||
Notes:
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