KINETIC DOUBLE SKIN FAÇADE AS AN ENVIRONMENTALLY RESPONSIVE STRATEGY TO REDUCE ENERGY AND IMPROVE LIGHT COMFORT IN AN OFFICE BUILDING IN DUBAI - UAE
The British University in Dubai (BUiD)
Façade technique as a response to the external climate factors has been discussing tremendously by many studies and in many regions with various weather conditions. However, in particular, the subject of the kinetic facade as a strategic solution to enhance the building energy efficiency have a shortage data for the researcher, especially in the region of the middle east. However, the performance of the kinetic façade is still questionable due to the lack of the experience, recorded data especially regarding high rise office buildings in Dubai, UAE and GCC area. These motivate the research to select an existing high rise office building with almost 65 floors as a base case model to demonstrate the dynamic louver system as a strategic environmental solution by enhancing the energy efficiency and scale the potential power saving. The building is allocated in Dubai, UAE which classified as hot, arid climate. The study accordingly establishes the baseline model as per the conditions and considering the local climate factors. The research validates the model by comparing the first energy simulation results against the actual record of the energy demand according to local Authority DEWA. Subsequently, the study develops the baseline by incorporate the configuration of the dynamic louver system to all façades. The model has been tested to figure out the optimal louvers configuration with various inclination started from 15, 30, and 45 till 180 degrees where the system performed as second skin scenario.The kinetic louver position as a double skin has been considering in three various scenarios (600, 1200 and 1800 mm). These simulations have been conducted within different seasons, different façade orientations on three different floors. The different Kinetic skin setting aims to demonstrate the effect of the model on total heat gain and heat loss of the building envelope and enhance total saving of power consumption by reducing the cooling load in additional to enhance the daylight level in the office building. The kinetic façade illustration and outcomes compared to the baseline model of existing building and the option of baseline with light control scenario. The research used Autodesk software to build the baseline model and take advantage of the software platform to simulate the model accordingly. Auto CAD and Revit software used to build the model; Flow Design software used to run the wind flow simulation and scale the effect of the system, and in particular, the optimal performance of façade as double skin with best cavity distance. The wind test results end up with the best cavity as 1800mm due to the optimal air velocity and air pressure in the cavity. CFD software used to measure the stack effect of the double skin, and the simulation concurs the disadvantage of high rise scale of double skin façade due to chimney effect factor where wind temperatures increased drastically. The Light performance simulated by Revit light analysis where the criteria of the test identified by scale useful daylight illuminance UDI factor and high level of illuminance HDI and below threshold light factor LDI. Also, HVAC system simulated by Revit software, and then, the total energy efficiency have been tested by same software advance by the Green studio and Insight 360 platform. The results of the research illustrate the kinetic façade system as quite challenged but presenting promised outcomes within a certain time in explicit and during a different season of the year. Specifically, the saving of the HVAC system reach 40-45% with double skin scenario, and in another hand, the balance between the daylight and the HVAC load presented by the dynamic louvre with inclination 75 –105 degrees lead to saving 20-35% of the total energy demand in average as an optimum efficiency and functionality. Moreover, in December the kinetic louvre system contribution in the total energy demand have mostly equal values with the same percentage of daylight and HVAC load. Therefore, 45-degree inclination presents the best scenario. Base on the result analysis of air flow test, light analysis, HVAC demand and the total energy portfolio, the research highly recommended the combination of the different scenarios which will enhance the system performance significantly with potential saving up to 40% of total power demand.
kinetic skin, office building, United Arab Emirates (UAE), facade technique, kinetic facade