Pedestrian Wind
City of London Wind Criteria
The City of London’s guidelines for wind microclimate ensure that wind conditions around public spaces are safe and comfortable, enhancing the overall usability of outdoor areas. The City of London uses a modified version of Lawson Wind Criteria named City Lawson Criteria. The categories and respective colors are shown below. Key changes from the Lawson…
About Pedestrian Wind Comfort
What is Pedestrian Wind Comfort? Put simply, pedestrian wind comfort is a measure of how local wind patterns impact the pedestrian experience. The speed, direction, and gustiness of winds can all affect how comfortable pedestrians will feel in a certain space. As a general rule of thumb, higher wind speeds and – in particular –…
RWDI Pedestrian Wind Comfort Criteria
The RWDI Criteria is a pedestrian wind comfort criteria developed by RWDI in the 1970’s to assess the predicted comfort and safety of pedestrians in outdoor spaces. These criteria have been widely accepted by municipal authorities as well as by the building design and city planning community. In general, strong winds and wind gusts can negatively…
Boston Pedestrian Wind Comfort Criteria
The Boston Pedestrian Wind Criteria is the standard used by the Boston Planning and Development Agency (BPDA) to assess wind impacts on pedestrian safety and comfort. Strong winds and wind gusts can negatively impact the pedestrian experience and may even pose a safety risk. The BPDA Criteria identifies standards for Wind Acceptability and Wind Comfort.…
Lawson Wind Comfort Criteria
The Lawson Pedestrian Wind Criteria is a globally-accepted standard used to assess wind impacts on pedestrian safety and comfort. In general, strong winds and wind gusts can negatively impact the pedestrian experience and may even pose a safety risk. Pedestrian Wind Comfort Criteria aim to classify different areas by the activities pedestrians may tolerate under…
Melbourne Pedestrian Wind Comfort Criteria
The Melbourne Pedestrian Wind Criteria is the standard used by the City of Melbourne to assess the impacts of wind and gusting on pedestrian safety and comfort. In general, strong winds and wind gusts may negatively impact the pedestrian experience, and may even pose a safety risk. Pedestrian Wind Comfort Criteria aim to classify different…
Hunt Pedestrian Wind Criteria
The Hunt et al Wind Criteria is a standard used (mainly in Taiwan) to assess the impacts of wind conditions in pedestrian-oriented locations. In general, strong winds and – in particular – strong wind gusts can negatively impact the pedestrian experience and may even pose a safety risk. Pedestrian Wind Comfort Criteria aim to classify…
San Francisco Pedestrian Wind Criteria
The San Francisco Wind Comfort Criteria is a standard used in the San Francisco Planning Code to assess wind impacts on pedestrian safety and comfort. In general, strong winds result in decreased pedestrian comfort – especially for more passive activities such as sitting – and may even pose a safety risk. The San Francisco Criteria…
RWDI Pedestrian Level Wind
A description of how to interpret the Pedestrian Level Wind Color Legend that is visible in the viewer.
Boston (BPDA) Pedestrian Wind Criteria
The Boston Planning and Development Agency (BPDA) has adopted two standards for assessing the relative wind comfort of pedestrians.
San Francisco Pedestrian Wind Criteria
San Francisco Planning Code requires buildings in the C-3 downtown districts to be shaped so as not to cause ground-level wind currents to exceed defined comfort and hazard criteria.
Melbourne Pedestrian Wind Criteria
The Melbourne pedestrian wind criteria are used in studies for this area. The comfort and safety conditions for these criteria are based on mean wind speeds and 3 second gust speeds, respectively.
Israeli Wind Criteria
The Israeli wind criteria 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.
Hunt Wind Criteria
The Hunt Wind Criteria is used in assessing the wind comfort conditions around the Project. As Orbital Stack understands, the Hunt Wind Criteria is commonly used in the Taiwan region.
Thermal Comfort
City of London Thermal Comfort Criteria
The City of London Thermal Comfort Criteria was developed to combine the effects of pedestrian wind and solar analysis to improve public space design. By understanding these factors, planners can strategically position parks, outdoor markets, cafes, and other public areas to enhance comfort and wellbeing. Thermal comfort analysis also helps pinpoint optimal locations for new…
About Thermal Comfort
Orbital Stack’s Thermal Comfort analysis provides objective metrics (e.g., SPMV*, UTCI) and vivid imagery that show how outdoor spaces meet their desired usage profiles. Thermal comfort is a complex concept as it accesses an individuals perception of temperature which are reliant on both physiological/environmental causes and psychological factors. The thermal comfort analysis combines wind and…
Directional Wind
Directional Wind Orbital Stack provides directional wind results on presentation plane surfaces as well as volumetric streamlines. Each of these results has its own color scale. Climate Scaled Wind Speed results use a horizontal color legend and are 80th percentile scaled. This means that the results shown consider wind speeds in the 80th percentile for that wind direction – qualitatively these are what can…
SPMV
SPMV* In an outdoor environment, the “Standard Predicted Mean Vote Modified” (SPMV*) metric is used as it can effectively account for the physics associated with elevated solar exposure and humidity ranges present outdoors. SPMV* is a modified version of the ASHRAE PMV metric which better accounts for the larger range of outdoor conditions. Thermal comfort is a useful concept and SPMV*…
Wind Cooling Potential (Ventilation)
What is Wind Cooling Potential? Wind Cooling Potential is a metric that provides the average wind speed of a location at an indicated time. It is generally understood that wind reduces the perceived temperature people experience in a given location. In the summer, a nice breeze on a hot day acts as a cooling agent.…
Thermal Comfort – SPMV % Inbounds Color Legend Explained
A description of how to interpret the Thermal Comfort – SPMV % Inbounds Color Legend that is visible in the viewer.
Thermal Comfort – SPMV (Temperate Climates) Color Legend Explained
A description of how to interpret the Thermal Comfort – SPMV (Temperate) – Color Legend that is visible in the viewer.
Thermal Comfort – SPMV HOT (Hot and Tropical Climates) Color Legend Explained
A description of how to interpret the Thermal Comfort – SPMV HOT (Hot and Tropical) Climates Color Legend that is visible in the viewer.
UTCI
The Universal Thermal Climate Index (UTCI) is a metric that attempts to quantify how people perceive given weather conditions by equating them to an equivalent temperature based on standard conditions. It calculates a comfort value for the actual conditions, and then determines an equivalent temperature that would create the same comfort value for that “standard” condition. The standard condition is a location at 50% relative humidity, low air speed, and mean radiant temperature equal to dry bulb.
SPMV Thermal Comfort Criteria
Thermal comfort is a complex topic that combines an understanding of human behavior and physiological response to external environmental conditions. There is a myriad of thermal comfort metrics in existence ranging from simple objective metrics to complex metrics which combine thermal systems and survey results.
Directional Wind
Directional Arrows
How to interpret the Directional Arrows in the viewer.
Directional Wind Color Legend (Volumetric)
A description of how to interpret the Directional Wind Color Legend (Volumetric) that is visible in the viewer.
Directional Wind Color Legend (Horizontal)
A description of how to interpret the Directional Wind Color Legend (Horizontal) that is visible in the viewer.
Streamlines and Generalized Wind Flows
When interpreting the results of a Directional Wind Study in Orbital Stack, the generalized wind flows will be show in color-coded streamlines.
Solar and Shade
Daily Light Integral for PAR
Photosynthetically Active Radiation (PAR) refers to the spectrum of light that plants can use for photosynthesis (400-700 nm). An estimation of the available useful radiation for plant life in a given area can be used to optimize the design of urban green features such as green roofs or walls. The amount of PAR that reaches…
About Solar
Sunlight and solar radiation are fundamental drivers of the outdoor climate. Solar conditions impact how pedestrians perceive comfort and experience outdoor spaces. As an example, shading from nearby buildings or trees can reduce the solar energy that reaches pedestrians, affecting one’s perception of warmth and coolness. The path of the sun also varies throughout the year,…
Sky View Factor
Sky view factor is the percentage of the visible sky unobstructed by obstacles as seen by an upward facing viewer. It measures of the fraction of the sky that is visible from a specific point in the project domain. Sky view is often used in urban planning and heat island studies to as it influences…
Clear Sky Solar Access
Clear Sky Solar Access is the number of hours during the day that a specific location receives direct sunlight. Solar access is helpful for assessing the position of potential solar energy systems, understanding natural lighting conditions, and evaluating solar availability in an exterior space or on a building surface. In Orbital Stack, the sky is…
Clear Sky Solar Exposure
Clear Sky Solar Exposure is a metric that quantifies the amount of direct sunlight an area receives as a percentage over a specified time period, assuming ideal, cloudless sky conditions. Like other thermal comfort metrics, solar exposure is defined over a season and time of day such as morning, afternoon, or evening. The percentage is…