Rome has a Mediterranean climate characterized by hot, dry summers and mild, wet winters. Average temperatures range from around 8.5°C in winter to about 31°C in summer. The city experiences moderate rainfall, with the wettest months typically being October and November.
Climate Analysis
In Rome, the bulb temperature, which reflects the combined effect of air temperature and humidity, varies significantly throughout the year due to its Mediterranean climate. The DBT can guide decisions on natural ventilation strategies. During cooler months, might opt for openings that allow for cross-ventilation, taking advantage of lower temperatures. Buildings designed with low thermal transmittance can reduce heat gain during high DBT periods in summer, improving energy efficiency.
Summer (June-August):
High levels of Direct Normal Radiation due to clear skies and higher sun position.
Moderate levels of Diffuse Horizontal Radiation.
Lower humidity levels, which is typical for Mediterranean climates during the hot and dry summer.
Winter (December-February):
Low levels of both direct and diffuse radiation due to shorter days and a lower sun angle.
Consistently high humidity, potentially contributing to a higher risk of fog, condensation, and damp conditions
Radiation Peaks:
Highest peaks occur in July and August, corresponding to maximum solar exposure in the northern hemisphere.
Lowest levels in December.
Energy Considerations:
This data is useful for designing solar energy systems (photovoltaic panels, solar thermal collectors).
In winter, winds predominantly come from the east and northeast, while in summer, they mostly come from the west and southwest. This could be due to seasonal weather systems, such as:
Winter: Influence of high-pressure systems over Eastern Europe and colder winds.
Summer: Influence of sea breezes from the Tyrrhenian Sea.
Wind Patterns
In winter, winds come from the ENE; in summer, from the W/WSW.
Strategies: Select a site that benefits from summer breezes for natural ventilation.
Solar Radiation
High direct radiation in summer (up to 800 W/m²).
Strategies: Orient façades to minimize afternoon sun exposure and consider solar panels.
Humidity
High humidity in winter (70%-90%) and lower in summer (50%-70%).
Strategies: Ensure good ventilation to manage moisture levels.
Exploring strategies for Optimization
These insights provide a strong foundation for further simulation in Infrared-city to fine-tune the building’s rotation and placement for optimal energy performance and comfort.
The solar panels on the roof allow for the generation of a large amount of energy, especially during the summer months, and the surface of the structure provides shading from solar radiation during the hotter months. The performance of the north-facing façade is improved even during the winter months, as part of the radiation coming from other directions passes through the twisted surface and irradiates part of the north-facing façade.
In summer months, fans help increase air circulation and can provide a cooling effect by enhancing evaporative which makes feel cooler. This is especially helpful when the ambient air temperature is not too high. Building materials with high thermal mass (like concrete or stone) absorb heat during the day and slowly release it at night, helping maintain stable indoor temperatures.
Highlight the optimal performance paths where multiple metrics are balanced for efficiency (e.g., lower energy consumption, higher daylight performance).
Increased Shading (SHD) reduces Cooling Loads but may slightly increase Lighting Loads.
Higher Window-to-Wall Ratios (WWR) can increase daylight autonomy (DA, SDA) but may also raise Cooling Loads.
Effective design strategies balance orientation, shading, and WWR to optimize daylight and minimize energy consumption.
Wind reduces the severity of heat stress, lowering the frequency of Extreme and Very Strong Heat conditions. In the presence of wind, conditions are more comfortable, especially during the hottest parts of the day.
Strategies:
In Rome’s hot summer, relying on wind for cooling can improve comfort. Conversely, areas shielded from wind may experience more severe heat stress, especially in direct sunlight.
Incorporate shading devices, overhangs, and vegetation to enhance comfort in the Sud Façade for the Summer.
Increase the windows distribution on the North Façade for the winter conditions.
Design shaded outdoor areas to encourage use during summer.
This analysis highlights the importance of natural ventilation and shading in mitigating heat stress during summer. Shade provides much better thermal comfort during the hot summer months compared to direct sunlight, especially during the peak afternoon hours.
Form-Finding for Optimized Design Strategies
Control the distribution of openings on the main facades. Increase the openings on the northern side, which receives little direct solar radiation but is not directly shaded by the buildings in front. Strategically position the openings on the southern facade, which in certain areas, especially in summer, is directly exposed to the sun
Maximizing daylight in winter and shading in summer ensures balanced lighting conditions and lower energy use for artificial lighting.
Winter Mode
Open Modules: Maximize sunlight penetration to the interior, enhancing daylight autonomy (DA) and reducing heating needs. The parallel coordinates plot supports this by showing that increased daylight reduces lighting energy consumption while maintaining high spatial daylight autonomy.
Summer Mode
Closed or Shaded Modules: Reduce solar gain and heat stress, especially in the afternoons when temperatures peak. The thermal comfort analysis showed significant periods of extreme heat in direct sunlight, particularly without wind. Ensuring proper ventilation through adjustable openings helps mitigate heat, as the wind analysis showed that natural ventilation significantly improves comfort levels in summer.
To optimize both natural lighting and ventilation in the building design for Rome, we have strategically chosen a building rotation that ensures:
Northern Façade Exposure in Winter
During winter, the northern façade will be kept in light, allowing for maximum daylight penetration when solar radiation is lower. This approach reduces the need for artificial lighting and improves energy efficiency.
Southern Façade Shading in Summer
In summer, the southern façade will be in shading mode, mitigating excessive solar radiation and reducing cooling loads. The solar radiation analysis highlighted peak intensities above 800 W/m² in July and August, making shading essential for thermal comfort.
