Green building analysis is essential for sustainable architectural design. Currently, mainstream simulation software addresses various environmental factors, including wind (Fluent, Phoenics), lighting (Ecotect, Radiance), energy consumption (ASK, DesignBuilder), and noise (Raynoise, Cadna/A). However, each program uses different modeling methods, often requiring engineers to create multiple models for the same project, which leads to inefficiencies.
Thanks to advancements in software technology, many green analysis tools now support interoperability through compatible interfaces. The rise of Building Information Modeling (BIM) enables the creation of a single comprehensive model usable across multiple analysis platforms. This significantly reduces engineers’ workloads. BIM involves creating a digital representation of a building that incorporates all relevant project information, simulating real-world characteristics digitally. This model supports various construction phases and can be applied throughout the project lifecycle.
1. Project Introduction
The project is a low-carbon experience center situated in a newly developed eco-city. The building comprises two above-ground floors, stands 12.7 meters tall, and covers 15,595 square meters. It integrates a low-carbon exhibition hall, tourist center, scenic area management center, commercial catering, and a clubhouse. The design supports low-carbon technology exhibitions, cultural displays, and scenic area reception management. Embracing green and low-carbon concepts, the project combines modern technology, sustainable solutions, and ecological landscaping to achieve a three-star green building certification in both design and operation.
2. Outdoor Environment Analysis
2.1 Outdoor Wind Environment
The initial building form was modeled in Rhino, featuring a hyperbolic roof that follows the terrain, seamlessly integrating with the landscape. This roof was imported into Revit to create a preliminary structural model. The model was then exported as a .sat file, with site details refined in SketchUp and Rhino. Finally, it was exported in STL format for wind simulation in Phoenics, optimizing the building’s shape and structure (see Figure 2).
The building extends roughly 250 meters. Early wind simulations indicated that long, narrow buildings can cause sudden wind speed variations and create dead zones, negatively affecting outdoor comfort. By aligning the design with the terrain and adopting curved forms, airflow in outdoor pedestrian areas improves, enhancing user comfort.
2.2 Wind Pressure on Building Surfaces
Facing the lake with an unobstructed southern exposure, the building experiences predominant southeast winds in summer and transitional seasons typical of the Huai’an region. Under these conditions, wind pressure on the windward side exceeds 2.2 Pa. The low-carbon experience hall is relatively low, with soil covering the north side. The roof experiences the lowest wind pressure, approximately -1.6 Pa, suggesting that operable skylights at the roof peak can effectively promote natural ventilation. The pressure difference between windward and leeward sides surpasses 3 Pa (see Figures 3 and 4).
To prevent vortex formation and stagnant air zones, the over 200-meter-long building is divided into three sections connected by a central corridor. This design improves airflow in primary outdoor activity areas. Additionally, it reduces indoor depth, shortens airflow paths, and decreases indoor air residence time, enhancing natural ventilation inside the building (see Figure 5).
The building’s central section serves as a low-carbon exhibition hall. By adjusting its form, this area achieves maximum wind speeds, making it ideal for installing wind turbines and showcasing wind energy on the facade.
3. Indoor Environment Analysis
3.1 Lighting Optimization
The preliminary Revit model was exported in GBXML format and imported into Ecotect for indoor environmental analysis. Skylights were installed atop both the main and annex buildings. Through comparisons of various skylight shapes and placements, the design was optimized to balance ventilation and daylighting, while complementing the building’s form.
3.2 Ventilation Optimization
During transitional seasons, when outdoor temperatures hover around 20℃ and indoor temperatures are higher, thermal pressure drives indoor air outward. With skylights open, indoor airflow reaches approximately 0.5 m/s. Installing operable skylights at the peak of the low-carbon exhibition hall significantly enhances natural ventilation.
Without skylights, the maximum indoor air age reaches 2800 seconds; with operable skylights, it reduces to 2000 seconds. Utilizing stack ventilation principles, natural airflow is effectively promoted, lowering indoor air residence time and improving overall air quality.
4. Other Key Green Building Features
4.1 Ground Source Heat Pump System
The low-carbon exhibition area at the building’s center uses a ground source heat pump system for heating and cooling. Two units, each with a capacity of 190 kW, are installed. One unit includes heat recovery functionality to supply domestic hot water. To highlight this technology, the heat pump room is designed as a tourable exhibition space. Using 3D BIM design, equipment placement and piping layouts were optimized to create an attractive and informative display.
4.2 Rainwater System
Roof rainwater is managed through a siphonic drainage system. Rainwater from selected rooftops first flows to outdoor drainage pools to remove the initial runoff (“first flush”). Subsequent water is collected in an underground raw water tank for further treatment. Remaining rainwater is discharged through outdoor pipes to the municipal drainage system.
Outdoor areas, including parking lots, use permeable bricks. Rainwater from fire lanes infiltrates these permeable surfaces or adjacent grasslands, enhancing groundwater recharge and reducing the urban heat island effect. This approach lowers the surface runoff coefficient and significantly decreases stormwater runoff volume.
4.3 Solar Photovoltaic Power Generation
The building faces south toward the lake, ensuring optimal sunlight exposure. Based on solar analysis and green building requirements, external shading systems are installed on both sides of the southern facade. An automatic outdoor display system, adjustable according to sun height, is installed in the central low-carbon exhibition hall. Integrated solar photovoltaic panels maximize solar energy capture on the facade.
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