When it comes to designing sustainable urban spaces, understanding the local climate and environmental factors is crucial. This analysis on environmental conditions for Porto focuses on climate, thermal comfort, solar radiation, wind analysis, and urban heat mitigation. Here are the key takeaways from this comprehensive research.
Climate Analysis: Understanding Porto’s Unique Conditions
Porto’s climate is influenced by its coastal location at 41° latitude. The city experiences high dry bulb temperatures during summer, with relative humidity often exceeding 70%. Wind patterns are predominantly from the north in summer, shifting to the east and south in winter.
Despite these cooling winds and high humidity, the Universal Thermal Climate Index (UTCI) analysis shows that cooling measures are required for much of the year. Additionally, the city’s infrared radiation is most intense from the eastern side. Porto’s climate is marked by significant temperature fluctuations throughout the year, with cooler nights exhibiting higher relative humidity due to nighttime temperature drops. Solar radiation decreases during these cooler periods, and wind speeds tend to calm as well.
Site Analysis: Harnessing Solar Potential
The analysis focused on a centrally located empty plot in Porto. Different typologies were explored to optimize sunlight exposure and solar radiation distribution. Since the eastern and western sides of the plot are adjacent to buildings, the focus was on optimizing the southern exposure.
After comparing different typologies, a design featuring a single massing with rotated floors was identified as the most effective. This design maximized access to sunlight while ensuring an even distribution of solar radiation. Further refinement included analyzing sun hours, solar radiation, and potential openings to determine the best location and orientation for the building on the plot.
Achieving Thermal Comfort: Passive Strategies for Optimal Design
Thermal comfort is a fundamental aspect of building design, and design strategies were categorized into traditional, current, and sustainable approaches. Recognizing that thermal comfort depends on user activity, passive strategies like passive solar heating for static activities and the use of fans for more active scenarios were proposed.
By using UTCI analysis, a large “comfort boundary” was identified where conditions are naturally comfortable. However, when wind speed was increased to 13 m/s, this boundary shifted toward higher temperatures, emphasizing the importance of controlling airflow. This insight guided passive design, where shading and ventilation strategies were key to enhancing comfort and reducing thermal stress.
Urban Heat Island Mitigation: Greening the City
Urban heat islands (UHI) are a growing concern in cities worldwide. To address this issue, the impact of adding greenery to the site was explored. Initially, a few trees were added but the results were unsatisfactory. By increasing the number of trees, a marked improvement in thermal comfort was observed, with more areas reaching “rural” comfort levels.
To further combat UHI effects, alternative paving materials were explored, comparing concrete, grass, and custom materials. The shift toward natural and permeable surfaces supports better heat mitigation and enhances overall urban comfort.
Daylighting Strategies: Balancing Natural Light and Solar Gain
Effective daylighting reduces the need for artificial lighting while controlling solar heat gain. Various window designs were tested, including large screen windows, grid-based square windows, and narrow vertical windows. Each design was paired with horizontal shading elements to balance light and reduce glare.
Findings showed that window shape and placement significantly influence daylight penetration and visual comfort. By optimizing the size and orientation of these openings, the design achieved a harmonious balance of natural light and shading, supporting energy efficiency and occupant well-being.
Wind Analysis: Harnessing Porto’s Breezes for Comfort and Ventilation
Porto’s wind patterns play a significant role in thermal comfort and passive ventilation. 3D analysis was used to study how building orientation, neighboring structures, and landscaping affect wind speed and airflow. Building rotation was found to influence wind flow, with certain rotations creating wind tunnels and others promoting better cross-ventilation.
To further explore these effects, ParaView analysis was used to assess wind velocity and comfort. By simulating wind from different directions, areas of discomfort were identified and the building’s orientation was refined to minimize wind-related stress. Adjustments like floor rotation and the use of shading elements improved wind comfort and ventilation.
With the integration of optimization tools, the rotation of the each floor, building position and overall rotation was optimized and best iteration was adapted to the design according to the wind speed analysis results.
After thorough analysis, several key insights were presented for optimizing building design and site planning in Porto:
- Sun Hours: Optimized building massing and rotation to maximize sunlight access and manage shading.
- Thermal Comfort: Used shading and passive ventilation to maintain thermal comfort throughout the year.
- Daylighting: Balanced window designs to enhance natural light while minimizing glare and excess heat.
- Wind Analysis: Refined building orientation and facade design to reduce wind discomfort and promote passive cooling.
For future development, a custom script was created to categorize sun hours (see daylight strategies section). This tool helps assign building functions based on light availability and comfort, offering a data-driven approach to sustainable design .The environmental analysis for Porto demonstrates the importance of climate-aware design. By optimizing for sun, wind, thermal comfort, and UHI mitigation, it showcases how smart design strategies can create comfortable, sustainable urban spaces. This holistic approach—from passive design to custom optimization scripts—provides a model for environmentally responsive architecture in Porto and beyond.
