Design Optimization of Productive Façades: Integrating Photovoltaic and Farming Systems at the Tropical Technologies Laboratory

Singapore’s high dependence on imported energy and food resources, and the lack of available land requires an efficient use of the built environment in order to increase energy and food autonomy. This paper proposes the concept of a productive façade (PF) system that integrates photovoltaic (PV) modules as shading devices as well as farming planters. It also outlines the design optimization process for eight PF prototypes comprising two categories of PF systems: Window façade and balcony façade, for four orientations. Five criteria functions describing the potential energy and food production as well as indoor visual and thermal performance were assessed by a parametric modelling tool. Optimal PF prototypes were subsequently obtained through the VIKOR optimization method, which selects the optimal design variants by compromising between the five criteria functions. East and West-facing façades require greater solar protection, and most façades require high-tilt angles on their shading PV panels. The optimal arrangement for vegetable planters involves two planters located relatively low with regard to the railing or window sill. Finally, the optimal façade designs were adjusted according to the availability of resources and the conditions and context of the Tropical Technologies Laboratory (T2 Lab) in Singapore where they are installed

Rethinking the Urban Design Process from a Data Perspective

35th International Conference on Education and Research in Computer Aided Architectural Design in Europe (eCAADe)449-46

Numerical study on the influence of wind and thermal stack on street canyon airflow pattern

Building ventilation potential and pollutant dispersion are greatly affected by the airflow pattern in street canyons. The airflow inside a street canyon can be the result of wind washing and/or buoyancy due to solar radiation. The objective of this study is to analyse, through numerical simulations, the relative importance of wind versus thermal stack on the airflow pattern. 25 cases with different Froude numbers (Fr) are analysed for a square street canyon. The results show that for Fr < 30 a secondary stack-induced vortex develops along the heated wall. A weak secondary vortex near the ground is created at Fr ≈ 6 - 7.4 pagesstatus: publishe

Visualisation of climatic environments based on the 'Test Reference Year'

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Modelling airflow and heat transfer on an experimental facade with external louvers

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MICRO-SCALE WEATHER DATA FOR ENERGY PERFORMANCE ASSESSMENT IN SINGAPORE

21st International Conference on Computer-Aided Architectural Design Research in Asia (CAADRIA)229-23

Assessment of modelling approaches for louver shading devices in office buildings

The presented paper focuses on the performance of exterior shading devices made of louvers. The analysis of the performance of these devices differs substantially from more traditional screens as their performance not only depends on the solar properties of the used materials but also on the position of the sun with respect to the louvers. In order to capture this complexity, models predicting the solar transmittance of louver shading devices have to be integrated into building energy simulation tools. A ray tracing method has been developed to describe the global solar transmittance of louver shading devices. Consecutively, this method is integrated in the dynamic building energy simulation program TRNSYS to assess the cooling demand and required cooling power in a south oriented office cell. The proposed integrated approach allows calculating the solar transmittance for each time step. The method however is also quite complex and requires an important computational effort. Therefore this research contrasts the results of this ray tracing method against the performance of other modelling approaches to assess the performance of louver shading devices in dynamic building energy simulation programs. It is shown that representing the shading device as a fixed reduction factor, independent of orientation, is an important simplification and is insufficient to incorporate the complexity of the performance and control of exterior louver systems. Deviations up to 102% were found for the cooling demand and up to 72% for the cooling power. The use of view factor models typically underestimate the cooling demand by up to 36% and the cooling power by up to 26%. The use of a simplified implementation of shading factors, however, is possible within acceptable margins if the results of a ray tracing calculation are implemented in a building energy simulation tool. Implementing the results of a ray tracing calculation of one representative average or sunny day reduces the deviations to 14% for the cooling demand and 18% for the cooling power. Performing additional ray tracing calculations for typical heating or cooling conditions or for every month further reduce the deviations to the order of 10% to 5% for the cooling demand and power respectively.status: publishe

Comparing micro-scale weather data to building energy consumption in Singapore

10.1016/j.enbuild.2016.11.019ENERGY AND BUILDINGS152776-791SWITZERLAN

A holistic strategy for successful photovoltaic (Pv) implementation into singapore’s built environment

10.3390/su13116452Sustainability (Switzerland)1311645

Investigation on airflow and heat transfer of a glazing facade with external louvers

The application of large glazed surfaces in office and residential buildings demands the integration of shading devices in the design of the facade in order to reduce overheating and high cooling loads during warm periods. However, the physical phenomena occurring at the facade, between the external layer of louvers, the glazing pane(s) and the interior space are very complex and depend on numerous factors. The objective of this study is to investigate the influence of solar radiation on the airflow and heat transfer on a glazing facade with exterior louvers. The study is performed in three phases: (1) design and modeling of the experimental set-up, (2) laboratory experiments and (3) CFD validation. This paper focuses on the first phase. The experiment set-up consists on a vertical test opaque facade with an external layer of aluminum louvers which is placed in front of a solar simulator.status: publishe