Estimating the impact of urban densification on high-rise office building cooling loads in a hot and humid climate

2019 ◽  
Vol 182 ◽  
pp. 30-44 ◽  
Author(s):  
Izabella Lima ◽  
Veridiana Scalco ◽  
Roberto Lamberts
2014 ◽  
Vol 20 (7) ◽  
pp. 731-737 ◽  
Author(s):  
Fu-Jen Wang ◽  
Meng-Chieh Lee ◽  
Tong-Bou Chang ◽  
Yong-Sheng Chen ◽  
Ron-Chin Jung

2021 ◽  
Vol 2069 (1) ◽  
pp. 012126
Author(s):  
O Fagbule ◽  
R Patel ◽  
U Passe ◽  
J Thompson

Abstract Building cooling loads are driven by heat gains through enclosures. This research identifies possible ways of reducing the building cooling loads through vegetative shading. Vegetative shading reduces heat gains by blocking radiation and by evaporative air cooling. Few measured data exist, so we gathered thermal data from a vegetative wall grown in front of a Mobile Diagnostics Lab (MDL), a trailer with one conditioned room with instrumentation that collects thermal data from heat flux sensors and thermistors within its walls. In spring 2020 a variety of plants were cultivated in a greenhouse and planted in front of the south façade of the MDL, which was placed in direct sunlight to collect heat flux data. The plants acted as a barrier for solar radiation and reduced the amount of thermal energy affecting the trailer surface. Data were collected through the use of 16 heat flux sensors and development of continuous infrared (IR) images indicating surface temperature with and without plant cover. The façade surface beneath the plants was 10-30 °C cooler than exposed façade areas. In further analyses, the heat-flux data were compared to IR temperature data.


Buildings ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 25
Author(s):  
Rizki A. Mangkuto ◽  
Mochamad Donny Koerniawan ◽  
Sri Rahma Apriliyanthi ◽  
Irma Handayani Lubis ◽  
Atthaillah ◽  
...  

Optimisation of shading devices in buildings is a broadly investigated topic; however, most studies only focus on a single façade orientation, since the observed buildings are typically located in high latitude regions. However, in tropical regions, optimisation of all façade orientations is required due to the relatively high solar radiation and long sunshine duration. While adaptive shading devices are a promising solution, they are not without disadvantages, and as such a combination of adaptive shading devices and a fixed shading device shall be considered. This research therefore aims to design the optimum internal shading devices on four façade orientations of a high-rise office building in a tropical city, considering fixed and adaptive shading design options, and to determine the impact on annual daylight performance using computational modelling and simulation. The simulation is carried out under: (1) fixed design option, focusing on the numbers and width of slats; and (2) adaptive design option, focusing on the slat angle on various conditions. It is found that both sDA300/50% and ASE1000,250 are only influenced by the orientation. Under the fixed design option, the sDA300/50% and ASE1000,250 targets can be achieved only on the north and south façades, and accordingly the adaptive design option shall be implemented on the east and west façades. Overall, this study contributes to knowledge regarding the optimisation of shading devices in high-rise buildings in the tropics, considering the daylight admission from the four cardinal orientations.


2021 ◽  
Vol 21 (2) ◽  
pp. 67-87
Author(s):  
Marilia Ramalho Fontenelle ◽  
Leopoldo Eurico Gonçalves Bastos ◽  
Sylvie Lorente

Abstract Recent studies underline that simple and non-invasive retrofit solutions can recover natural ventilation potential in existing buildings under temperate climate. Nonetheless, the efficiency of these solutions in dense urban contexts under hot and humid climate remains unclear. This paper aims to evaluate the thermal comfort gains caused by natural ventilation when retrofitting an office building in downtown Rio de Janeiro. Computational Fluid Dynamics (CFD) and thermal simulations are carried out on Ansys CFX and Design builder to assess indoor air flow before and after retrofit. The diagnosis of the current scenario indicates that the surrounding buildings block a significant part of the wind flow, and occupants experience only a few hours of thermal comfort during the year, especially on lower floors. To increase indoor air flow, the fixed upper windows were transformed into pivot windows and kept open permanently. This measure increases the annual hours of thermal comfort by 0.5-35%, depending on the floor and the adaptive comfort model. These findings suggest that natural ventilation itself may not be sufficient to ensure occupants' comfort throughout the year under the investigated context.


2020 ◽  
Vol 172 ◽  
pp. 22008
Author(s):  
Alexander David ◽  
Thomas Bednar

Near the center of Vienna one can find the world’s first office tower which was designed to feed more energy into the power grid than is required to operate and use the building. This building is the result of the refurbishment of an over 40 years old high-rise building. The so called “(Plus-)Plus-Energy Office High-Rise Building” offers office space for several institutes of the TU Wien. The building was planned and simulated under the premise that every office occupant uses highly energy-efficient IT-hardware which would result in an average electrical power consumption of approximately 50 Watts per office workplace. Moreover, the cooling system of the building was planned for this case, allowing only for a minimal internal thermal load. To realize the simulation results, conventional office IT-hardware needs to be substituted by energy-efficient one and all intensive computing processes, e.g. simulations, ought to be outsourced into the building’s server room. This research presents the challenges faced during the transition from a conventional scientific office setup to an energy-efficient one. The method which was used to encourage the occupants to participate in this transition process will be discussed and the impact on the building’s energy consumption will be shown.


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