Towards Achieving Sustainable Environmental Efficiency: Rationalizing Energy used in Educational Buildings of University Campus

The research deals with a practical and analytical study comparing the use of the computer program for digital simulation, Design Builder, to calculate the amount of energy consumption in buildings, as the aim of the research is to conclude the most influential architectural elements in reducing energy consumption in the typical building of Al-Azhar College of Engineering for Girls (CEG). This is done by calculating the amount of energy consumption of the college building with its existing specifications while making architectural modifications to the building to conclude which elements have an impact on reducing energy consumption under the influence of the climatic conditions of the city of Cairo. These architectural elements include treating the glass surfaces and curtain walls in the building and increasing the operating temperature of the air conditioners to cool the building, as it is clear from the simulation results that the greatest reduction in the building’s cooling load is by 40%. The research concludes with recommendations that contribute to energy rationalization in educational buildings on campus, thus achieving efficiency in the internal and external environment.


Introduction
The building sector accounts for about half of the energy consumption in different countries.This has led to the design of new energy-efficient buildings, but existing buildings still consume a lot of energy [1].In Egypt, development efforts have focused on renovating finishes to obtain quick results with limited costs, neglecting the role of architectural processors and limiting the concept of sustainability to new buildings.This approach neglects the treatment of existing buildings, which could be made more energy-efficient and have a longer lifespan, saving energy and operating costs.The primary goal of a sustainable building envelope is to create a comfortable indoor climate that meets the changing needs of occupants and institutions over the lifetime of the building [2].This is achieved by using both internal and external climate elements.For example, the building envelope can be designed to take advantage of natural light and ventilation, while also minimizing heat gain from internal sources.This helps to reduce energy consumption and create a more comfortable and healthier indoor environment.The research methodology that the performance of the building's façade, whether solid or with openings, will be measured by how well it meets the shape, overall performance, and energy efficiency.In addition, the façade's performance will be evaluated by calibrating these characteristics and determining their suitability for the climatic conditions of the region for which they were designed.The purpose of this study is achieving sustainability strategies to an existing structure of Al-Azhar College of Engineering for Girls (CEG) to improve the environmental impact of our architectural treatments and consider the consequences of components of construction occupancy of the building.The research aims to study energy consumption, identify opportunities to rationalise energy consumption, and propose solutions to achieve sustainability at (CEG).

Stages of Applying the Façade Design Methodology
The applied study is based on treatments that can be applied to buildings to reduce energy consumption during operations and achieve sustainability concepts.This is done by evaluating the thermal performance to show the percentage of reduction in energy consumption that can be achieved after development.Energy consumption evaluation through simulation using a program to calculate energy consumption in the building to evaluate the various architectural alternatives affecting the rationalization of energy consumption [3], which were identified in choosing the type of building windows.
The following stages will be followed in applying the façade design methodology:  Research the site's parameters. Complete the preliminary architectural design process. Block layout and routing. Select the materials to be used. Select the type of glass to be used. Finish the preliminary visualization of the façade. Test the overall performance of the façade using the simulation program mentioned in the research. Develop and review the initial design. Select and approve samples of selected materials and ensure compliance with objectives. Improve performance and gain access to this site's database.Develop the final solution for the building's façade.

Aim of the Research
The applied study aims to improve the energy efficiency of the building more sustainably by evaluating alternative architectural and technical solutions and attempting to combine them and introduce sustainability concepts during the development processes to increase the life span of the building, reduce energy consumption, improve building performance, achieve thermal comfort for occupants, and improve environmental quality.Interior and reduce carbon emissions.

Hypothesis of the Research
Presentation of hypotheses and practical studies on energy efficiency in buildings, and examining technical and structural elements that impact energy consumption reduction, this study aims to investigate the following hypotheses and dimensions:  Evaluating the energy usage of the standard simulation scenario for the current construction by conducting a Design Builder program simulation to estimate the structure's energy usage.Additionally, crosschecking simulated results with the genuine electric energy usage reports of the college building to ensure consistency. A computer program will be utilized to establish the most efficient orientation for the building, calculating the amount of solar radiation on its roofs throughout the year in each direction. Using the same program, the various architectural options impacting energy consumption optimization will be assessed.These options were identified as follows: -Improving the properties of the transparent section: Improvement of the properties of the glass within the opening to achieve the required resistance whilst maintaining the current area of the opening.-Shade the exposed area using one of the External Shading methods as it is in the current situation.

Climate and location 4.1. Climate Analysis [4]
The "climate consultant 5.3" program was used to conduct the climatic analysis of the building site.
Figure (1) shows the prevailing winds are southeasterly, with an average speed of 10 m/s. the total surface irradiance varies between 100 and 700 watts/m2/hour analysis of the building site.

Thermal Comfort
Design criteria suitable for thermal comfort: • Use ceiling fans or move indoor air to achieve thermal comfort.
• If the windows are well-shaded and directed towards the prevailing breezes, natural ventilation can dispense with air conditioning, allowing us to reduce the percentage of windows that can be operated by air conditioning.• Use light-colored materials and cool ceilings, and the air conditioner should be highly efficient or Energy Star-rated and cost-effective [5].• Placing door and window openings on opposing sides of the building to allow for cross ventilation.

Energy performance evaluation in (CEG), using the following analysis method:
Through its suitability for the surrounding environment, one of the existing buildings )CEG) was chosen to determine the extent to which sustainable solutions can be implemented.At the end of the research, an applied study is conducted using the Design Builder program [6] to simulate the current situation of the students (CEG) and determine energy consumption ratios.

Information Gathering:
The building used for the study is a governmental and educational building located in Nasr City, Egypt.General description of the building: The structure is rectangular and overlooks three major streets.
Internal of the building: The building consists of administrative offices, lecture halls, and classrooms.The upper floors can be reached through a main staircase and two elevators.
The building from the outside: The building consists of a ground floor and three recurring floors, with three facades overlooking the internal streets of the university see Figure (2).

Entering the Data.
The characteristics of the current building's outer envelope, where the outer envelope of the building affects the amount of heat transfer inside and outside the building, which is represented in the specifications of the external walls and the type of window glass used, table (1) shows the Occupancy Scheduled for the Building of (CEG) on the Design Builder Program, table (2) shows the characteristics of the building envelope of (CEG) before renovation.

Facade Elements Investigation.
The research is concerned with the importance of renovating energy-efficient buildings because openings are one of the primary determinants of energy consumption in buildings that are considered accurate in design to achieve an optimal design [7].

Outside Walls
The actual external wall section was analyzed to calculate the total U-value, as shown in Table (3), and the R-value was found to be 2.32 W/m2.According to the Egyptian Energy Code, the U-value of the wall should be 0.43 W/m2, which can be achieved by applying some types of thermal insulation to the walls [5].

Windows
The windows have been evaluated for their actual properties and are made of plain glass with no treatments, coatings, or tints.It allows for very rapid transmission of light and heat through it, making it preferable for use in internal spaces [8].

Evaluate the Current Situation
The phase of development and ideation: After studying the determinants of the façade elements and learning about the properties and specifications of the materials, the research moves on to the stage of development and planning, which aims to innovate or create new ideas to achieve the required functions and technical specifications of the outer shell to reach a strong idea with high-cost savings.Finding alternatives to perform the required functions is dependent on the following factors [9].Not to change the architectural characteristics formation of the façade except within the designer's framework.
 Achieving the Energy Efficiency Improvement Code's minimum mandatory requirements.
 The impact of each alternative on the structural loads of the building. Possibility of allocating areas in the plan for climatic treatments [6] . The ease with which the proposed materials can be obtained. The extent to which the façade treatments are compatible with the building's structural requirements.Here comes the role of attempting to find good alternatives that achieve the desired goals at an acceptable cost.This stage includes the steps of presenting ideas, evaluating stage, and then selecting ideas.

Generating Ideas
Generating ideas entails presenting several alternatives and comparing each one.Every member of the project work team participates in brainstorming for each item of business, and each of them gives his or her idea in his or her area of expertise [01].
Ideas for the Façade Dark Elements:  Use materials with excellent thermal properties.
-Changing the bricks on the facades -Choose the external cladding types (to increase the wall's thermal resistance).
-The use of light exterior paint colors -Increasing the number of thermally resistant roof layers  Increasing the thickness of the wall: Increasing the thickness of the wall while using the same material. Adding an air gap: Calculating the required resistance difference and determining the thickness of the air void to be achieved when adding an air void. Addition of insulating material: Determine the type and thickness of the proposed insulator, as well as the resistance difference required.Ideas for Façade Openings:  Reducing the opening area to achieve the required thermal resistance: Calculating the minimum opening space required based on vacuum requirements to achieve the smallest opening area while not affecting the proposed architectural formation of the outer cover. Improving the transparent part's properties: Improve the properties of the glass in the aperture to achieve the required resistance when adhering to the existing aperture area. Shade the opening part with one of the external shading methods: The type and shape of the exterior shading means are determined if the architectural configuration allows for the presence of shading elements on the façade.

The Evaluation and Selection Stage
The goal of this step is to study and analyze all the ideas that were previously mentioned in the ideation stage, and because the ideas are not judged at that stage, there is likely a large number of inappropriate and impractical ideas.As a result, serious ideas are evaluated and chosen here, and their quality is assessed.And its applicability, which goes through the following stages [11]: Determining the criteria for evaluating ideas: The work team establishes the standards for judging, evaluating, and grading ideas, and grades are assigned to ideas based on those standards.We proceed to the next step because these standards are considered relative standards and vary depending on the item under study, whether it is a dark or transparent element [12], as well as the proposed design of the façade or the required thermal resistance.The preliminary evaluation of ideas: The research team begins by presenting all ideas related to all business items, and everyone who proposes an idea must explain it briefly and quickly, the idea is judged, and the value index is clarified for it if it increases or reduces the quality (architectural formation -thermal properties) and cost.Table (4) shows the method of collecting ideas Outer cover treatments and explains their advantages and disadvantages.-Limited thermal resistance difference resulting in the use of varied materials.
-Obtaining a higher thermal resistance than the previous alternative.
-The exploitation of a larger area than the project plan.
-Add a vacuum.
-Obtaining a higher thermal resistance than the previous alternatives.
-The exploitation of a larger area than the project plan.
-Add an insulating material.
-Obtaining a higher thermal resistance than the previous alternatives.
-An increase in the cost of the item over the previous alternatives.-The exploitation of a larger area than the project plan.

openings
-Reduce the opening area.
-Savings on item cost.
-Increase the thermal resistance of the outer shell -Reducing architectural formation.
-Violation of some functions, such as the view and providing the required natural lighting.-improving the properties of the partially transparent -Not to limit the architectural formation.-reaching the required resistance without affecting the proposed design.
-Cost increase over the previous item.
-Partially shade the aperture -Cost saving while conserving the opening space, especially in the eastern and western facades.
-Affecting the architectural formation.
-Completely shade the aperture -The increased thermal resistance of the facade.
-Influencing the architectural formation.
--Violation of some functions, such as the view and providing the required natural lighting In summary, the stage of development, research, and preparation of the study's initial report concludes, during which innovative ideas or ideas that can be combined with another idea are developed to reach a strong idea with high returns in a sustainable outer shell while saving costs.

Windows
There are types of glass that consist of Single-layered glass and double-layered low-E glass optical, as shown in Figure (2).Table (5) shows optical and thermal properties of the glass types proposed, four types of glass are examined on the southern façade as it is exposed to the sun to conduct an accurate energy analysis and evaluate the impact of the type of glass on the energy efficiency of the building.They are used in the following ways: 6.1.The base case is created for comparison and analysis.

6.2.
A single transparent glass with a thickness of 6 mm is used in the new model for the study case because it is the cheapest and most readily available type among the resident glass types, and it is manufactured locally.

6.3.
Occupancy loads, general lighting, computers, and equipment are turned off or considered zero to isolate the effect of the glass factor from the effect of other factors and evaluate the effect of glass on building envelope performance.

The façade's location, orientation, and window-to-wall ratio (WWR), as well as the HVAC system
and HVAC schedules, are kept consistent.  5. Optical and Thermal Properties of the Glass Types Proposed [13].
Figure (4) shows the simulation results of the new model for the basic case that about 97% of the total heat entering a building through external windows is solar radiation.The types of glass explored are available on the local market from several suppliers, but the optical and thermal properties are provided by the manufacturer (Saint-Gobain Company).
Five simulation experiments were conducted each year to evaluate the type of glass for five different types compared to the base case, where Single Glazing Blue is the path of the base case, and the results are shown in Fig.
The lower the SHGC value, the less heat gain of the glass that can enter the building spaces, and thus a decrease in the demand for cooling energy.The U-value effect of the glass, on the other hand, was insignificant because less than 1% of the total texture resulting from the glass heat gain transmitted long-wave solar radiation.Figure (5) shows the cooling energy (cooling electricity) that is provided annually in kilowatt-hours, except for the basic case.As well as the percentage of energy saved w.r.t.According to the previous analysis of the results, using a special type of treated glass and adding a reflective coating to the exterior can save approximately 40% of the cooling electricity in the case study where the WWR is greater than 70%.The optical and thermal properties of layers of a type of evaluated glass are shown in the table (6).

Conclusions
The project of Al-Azhar College of Engineering for Girls (CEG) was chosen, and the scope of the research on alternatives to the outer shell processors was then determined.Then comes the attempt to find alternatives that achieve these functions by searching for and organizing alternatives and new ideas that achieve these functions, followed by the stage of evaluation and selection in which ideas are evaluated.
 The concept of developing existing buildings is a sustainable trend in and of itself, as it seeks to benefit from the fact that the building is existing, preserve the energy contained in the materials and elements of the building, and increase its life span, in addition to reducing carbon emissions, improving the quality of the internal environment and many economic and environmental advantages. The concept of sustainable development is not only applicable to new buildings but also to existing buildings.This can be achieved by incorporating sustainable design concepts into the planning stages of building developments. The process of increasing the energy efficiency of existing buildings helps to improve building operations, reduce energy consumption and costs, extend building life, and reduce CO2 emissions. When the WWR opening ratio is high (over 70% in the case study), the results show that there is no or negligible effect of adding insulation to the walls, as the main source of heat gain is the solar heat gain from the walls and the windows outside. Using a special type of treated glass and adding a reflective coating to the exterior can save approximately 40% of the cooling electricity in the case study where the WWR is greater than 70%. Low-SHGC glass panels in windows reduce the need for building cooling in hot climates. The roof insulation on the top floor of the building plays a key role in reducing the solar heat gain of the building  Energy subsidies in Egypt, which are currently being reduced and will be phased out in the future, present an excellent opportunity for building designers to focus their design efforts on energy efficiency, including the design of low-energy and net-energy buildings. Energy-efficient building design and technologies face several challenges and economic difficulties due to the relatively low return on investment of some alternatives, designs, and technologies.Monetary policy targeting energy efficiency investments in general and energyefficient buildings in particular should therefore be reconsidered by lowering interest rates.

Figure 1 .
Figure 1.The "Climate Consultant 5.3" Program Used to Conduct the Climatic Analysis of the Building site [4] .

Figure 3 .
Figure 3. Single and Double Layered Glass.Source: By Author.

Figure 4 .
Figure 4. Shows the Heat Gain of the Selected Glass Substitutes Compared to SHGS of (CEG) on the Design Builder Program.Source: By Author.

Figure 5 .
Figure 5. Providing Annual Cooling Energy in kilowatt-hours for the Building of (CEG) on the Design Builder Program.Source: By Author.

Table 4 .
Shows the Method of Collecting Ideas with the Façade Processors.Source: By Author.

Table 6 .
The Optical and Thermal Properties of the SGG REFLECTASOL Layers of (CEG) on the Design Builder Program.Source: By Author.