Cover: The glass section relates to the thermal performance of the test case (Marina Square in Al Reem Island, Abu Dhabi). Photo: By Narmeen Tariq Ali Abu Hilal). The hot climate of the UAE generates unique challenges for architects and building engineers seeking energy efficiency in high-rise residential buildings.
Introduction
- Overview
- Relevant Literature
- Energy Consumption
- Building Façade
- Statement of the Problem
- Research Questions
- Aim and Objectives
- Research Structure
- Conclusion
What are the optimal glass properties/characteristics that can optimize the double facade performance in terms of energy consumption in the residential high-rise buildings in Abu Dhabi's hot climate. To identify the impact of glass facades on energy efficiency and energy consumption in high-rise buildings in Abu Dhabi.
Methodology
Research Approach
- Investigating Tools
Case study: statics is used to identify the problem and the characteristics of the building. The energy performance of the high-rise residential building will be investigated and investigated based on this method.
Assessment Methods
- Simulation Tool (Energy Plus)
The qualitative method is based on observation, description and interpretation of the experience of people in the area. These software packages can be used to create the building geometry and extract the required Energy Plus Input Data File for.
Selection of Marina Square Abu Dhabi
- Abu Dhabi Climate
- Marina Square in Al Reem Island, Abu Dhabi, UAE
Based on the literature study, the best recommended values have been tested for the cavity between the double skin layers and for the type of glass and glass layers. Finalize the result and the output with the best energy performance for the final model and write the recommendation based on the results.
Literature Review
Building Façade
- Visual Comfort
- Daylight
- Natural Ventilation
- Thermal Comfort
The lower the solar factor, the greater the solar protection, and the greater the efficiency of the solar control glass (Alaa El Di & Fikry, 2019). The amount of solar transmission through a building facade is proportional to the available radiation, surface area, alignment and heat transfer specifications of the visible facade.
Double Skin Façade
- The Performance of the DSF
- The Importance of the Double Skin Façade
For tall buildings it is not suggested because the height of the stacks is limited (Oesterle, 2001). In winter conditions, the cavity can be closed at the top and bottom to take advantage of the greenhouse effect created in the cavity. Because the outside air is heavier, because it is cooler, there is too much pressure at the bottom of the hole, forcing air into the middle area.
The air flow falls from the bottom of the facade through an electric flap to control the amount of ventilation. In addition, the use of high-performance glass in a double-layer facade can reduce cooling (Michel, 2007). According to the study (Gratia, 2004), when the double facade is closed and external.
Double Skin Façade Design Aspects
- Geometric Features
- Dimensions of the Cavity; Airflow Path
- Shading Position (Venetian Blinds)
- Opening’s Geometry and Airflow Amount DSF
- Material Properties
DSF Cavity Measurement – Of all DSF geometry specifications, the effect of aspect ratio on fluid flow and heat transfer within the cavity is the best studied. In the approach of refreshing the internal air curtain, it is possible to further increase the heat gain in the room from the exhaust tunnels (Manz, Schaelin & Simmler, 2004). The shading system, when built into the cavity, is the most important structural component in controlling the thermal and fluid dynamics element of the double-layer facade.
The width of the entrance must be taken into account as it has a direct influence on the average velocity of the cavity, making it larger for narrower cavities. Specifically, SHGC can be reduced by up to 30% along with the temperature of the exterior glazing and installed PV panels with the right combination of the forced air flow rate and cavity depth (Preet, 2020; Aleksandar & Francesco, 2021). The heat release from radioactivity is the most important factor in the thermal functioning of DSF, and therefore the radiation specifications of the shading system play an important role.
Case Studies
- Supreme Audit Court Building in Tehran
- Central Park 08, Dubai, UAE
- Conclusion and Lesson Learned
On each of the building's four sides, the sensors for the outside temperature are installed on the seventh level, 50 cm from the outside. The interior sensors were placed on the walls, on two sides, and 150 cm from the floor in the center of the space. e) Summer measurements. When this side is in the shade, the cavity temperature will reach 7ºC less than that of the outside.
The temperatures in the cavity of the building with DSF and the external temperatures of the outer walls of the buildings with and without DSF were calculated. Glazing options were also limited to a single type of double glazing with a minimum U-value of 1.7 W/m2K. The tallest tower has 46 levels, the middle tower has 36 levels and the small tower has 25 levels. Abu Dhabi is considered one of the fastest growing places in the world.
Marina Square Case Study
Marina Square Overview
- Residential Building
- Building Façade
- Building Façade Performance
Marina Square is the first phase of the iconic multi-billion dollar project on Al Reem Island. The skin has a double glazed single facade with 24mm thickness; as shown in Figure 43, the inner layer is 6 mm clear glass, then a 12 mm cavity, and the last layer, which is 6 mm with colored glass. Regarding thermal model behavior when replacing a glass facade, Energy Plus calculates the thermal interactions between the old glass envelope and the new double skin facade type based on the cavity and the glass type variables in Energy Plus Application.
The lighting percentage for the studio is 30%, which is higher than the required design percentage. The one bedroom apartment has one window 3.6 meters wide by 2.4 meters high in the hall, and the other window is 2.3 meters wide, the same height as 2.4 meters in the bedroom. However, they have different widths; the smaller window width is 2.5 meters, the medium window is 3.6 meters, and the larger window width is 5.4 meters, and the percentage of opening to the floor area is 26.5 meters.
Data Collection
- Wall Construction Properties
- Cooling System
- Climatic Data
- Data Collection
The indoor air conditioning used is a central chiller in the building and the air handling controller is distributed over each floor and separated in each unit. 83 rejection systems, the central cooling installation, the distribution system and the end users and what Chilled Water District Cooling Provider processes. The extreme summer temperature for Abu Dhabi is 42.0°C and the minimum winter temperature is 11.8ºC.
In addition, Table 14 summarizes the minimum and maximum annual temperature values for the months with the possibility of precipitation and the number of rainy days (Vreme, 2022). This section contains details of AC energy consumption and feedback from surveyed residents and residences in terms of building facade, heat. The average family income and the percentage to be paid for air conditioning and electricity consumption are also included in the survey in order to get accurate answers.
Energy Consumptions Analysis
- Studio
- One-Bedroom
- Two-Bedroom
This chart is drawn based on existing AC bills for the existing single-glazed double-glazed window with U-value = 5.68 (W/m2 K). In this part, the research presents the existing values of electricity consumption during the months throughout the year. One bedroom AC consumption and electricity based on existing bills and glass properties are discussed below. a) AC consumption.
In this section, the research discusses the existing values for AC consumption throughout the year. This section discusses the results of the 2-room AC and electricity consumption based on the existing bills for the existing double glazing with a U-value of 5.68 (W/m2 K). In this part, the research analyzes the existing values of AC consumption throughout the year, focusing on the month of August.
Double Skin Façade Application
- DSF Variables
- Simulation Validation
- DSF Simulation and Results
95 Table 15: The details of the selected 35 cm cavity with different glass type U-value for the simulated and proposed DSF. The simulation of the existing data is shown in appendix 4 to be compared with existing data. The studio DSF simulation results are shown in Figure 69 during the middle day of the peak month (August 15).
The result of the DSF studio simulation is shown in Figure 71 at the middle of the day of the maximum month (August 15). The DSF simulation result for one bedroom is shown in Figure 73 during the middle of the day of the peak month (August 15). The DSF simulation results for two bedrooms are shown in Figure 76 during the middle of the peak month day (August 15).
Energy Consumption Results
- Electrical Consumption Results (Non-AC Consumption)
- Air Conditioning Consumption Results (Cooling)
The optimal DSF design to reduce energy consumption and AC consumption is a 35cm opening DSF with a single layer of double glazing on the inside and a single layer of low-e double glazing on the outside. This section describes the electricity consumption results for the simulation process of the optimally selected facade, DSF with a 35 cm cavity with one layer of double glazing inside and one layer of Low-E double glazing outside. The graph shows the stability of energy consumption with a clear decrease in electricity consumption during the year.
The results of the AC energy consumption for the simulation process of the optimally selected facade, DSF with a cavity of 35 cm with a single layer of double glazing on the inside and Low-E double glazing on the outside. The results are also presented in comparison graphs to clarify the reduction in AC energy consumption between the existing single facade and the proposed new DSF. Figures 82, 83 and 84 show the compared DSF air conditioning consumption data for the studio, one bedroom and two bedrooms sequentially.
Discussions and Conclusion
- The Variables of the Double Skin Façade
- The Simulation of the Double Skin Façade
- Recommendation
- Conclusion
This chapter discusses the final results of the simulation of the optimal two-layer facade with its effect on a) energy consumption, b) AC energy consumption and c) energy efficiency. However, this research proved that energy consumption could be improved by improving the facade type for a double-layer facade. Numerical analysis of air ventilation management and evaluation of the behavior of double-layer facades, Energy Build.
Three-dimensional simulation with a CFD tool of the airflow phenomena in single-floor double-skin facade equipped with blinds. Influence of geometric design parameters of double-clad facade on its thermal and fluid dynamic behavior: A comprehensive review. Thermal behavior of double skin facade in terms of energy consumption in the climate of Northern Iran-Rasht.
The Questionnaire and Answers
Electricity and AC Bills
The Example Layers for Calculating the U-value
