Farrah G. Mohammed
| Ghada G. Abdulwahab | Mahmood H. Mustafa*
© 2026 The authors. This article is published by IIETA and is licensed under the CC BY 4.0 license (http://creativecommons.org/licenses/by/4.0/).
OPEN ACCESS
In hot‑arid cities such as Baghdad, many university buildings exhibit persistently high energy demand because their envelopes admit excessive solar gains. At the same time, facility managers often lack access to advanced building‑energy simulation tools. This paper introduces a simple climate‑responsive retrofit protocol for an existing Deanship Building at Al‑Mustansiriyah University, combining freely available NASA POWER climate data with an Excel‑based solar gain model derived from ASHRAE fundamentals. The protocol quantifies elevation‑specific solar loads and tests three low‑cost interventions: deep horizontal canopies, high‑performance low‑solar‑gain glazing, and vegetation‑based shading. The results show that upgrading the glazing in the most exposed offices and halls can reduce cooling‑related solar gains through windows by about one third. At the same time, vegetative shading delivers additional reductions of roughly one-fifth of the summer solar load. When combined with properly dimensioned canopies, these measures are able to cut the summer solar load on the most exposed elevations by around one-half, which can translate into noticeable decreases in cooling demand and associated carbon emissions for the case study building. In addition to these quantitative outcomes, the study proposes a replicable, step‑by‑step decision‑support protocol that allows resource‑constrained campuses to prioritize envelope retrofits, turning administrative buildings from energy‑intensive facilities into low‑carbon, energy‑efficient campus assets in similar hot‑arid higher‑education contexts.
arid climate retrofitting, building envelope optimization, data-driven protocol, green campus transformation, passive cooling strategies, resource-constrained environments, solar heat gain control, university energy efficiency
University buildings in hot and dry regions typically exhibit very high energy consumption. Their envelopes are not very efficient, and hence, they rely on mechanical cooling a lot, which turns out to be very power-consuming. Energy performance is an emerging global concern, as the building sector is a major energy consumer and contributor to greenhouse gas emissions. In the case of schools and universities with limited budgets, it is not only doing what is right to combat climate change- it is also a practical economic necessity for budget‑constrained institutions [1].
Campus buildings can act as a ‘living laboratory’, where real‑world climate‑responsive design solutions can be implemented and monitored. They are active, occupied, and can demonstrate climate-intelligent design solutions that have real-life applications. Back in Baghdad, the situation is becoming more difficult. Urban heat‑island effects and rising ambient temperatures lead to extreme thermal loads, making prolonged air‑conditioning operation during the summer months almost unavoidable. The findings of local research indicate that basic passive interventions, such as shading, improved glazing, and thermal mass, can reduce cooling energy by over 20 percent. The ideas, however, are hardly implemented, as the instruments and expertise to model them are costly and complicated [2].
A significant gap exists in countries such as Iraq, where advanced simulation software is often unaffordable or inaccessible to facility managers and architects. The advanced simulation software needed to estimate the value of retrofits is frequently unable to be purchased or obtained by facility managers and architects. This is why we are in dire need of a simple data-driven process through which the local stakeholders can make wise, evidence-based decisions without imposing prohibitive costs [3].
This paper aims to demonstrate that even a specific architectural modification can transform the Deanship of the Faculty of Engineering at Al-Mustansiriya University into a green campus asset instead of an energy‑intensive liability. The study develops a practical retrofit protocol by combining free NASA POWER climate data with a straightforward model of computation, specifically designed to address the hot-dry climate of Baghdad. It discusses the amount of sun radiation the building is currently admitting and measures the effect of three retrofit alternatives: deep horizontal overhangs, high-efficiency low-E windows, and increased vegetation. It aims at providing a practical roadmap to be followed by the campus planners so that the universities in Iraq can change towards a sustainable and resilient campus (Figure 1).
Figure 1. Mindmap of the paper
In recent decades, Baghdad has been witnessing a significant rise in temperatures, especially during the summer months, as a result of the overlap of global climate change factors with rapid urbanization and the increase in urban heat islands, leading to an increase in thermal loads on buildings and raising the demand for mechanical cooling [4].
In this context, university buildings are one of the most affected types of public buildings due to their extended working hours, high occupancy density, and continuous use of computer equipment, lighting, and air conditioning systems [5].
Local studies on Iraqi university campuses indicate that energy consumption for cooling accounts for the largest proportion of total electricity consumption in the summer months and that educational and administrative buildings in Baghdad have become almost entirely dependent on separate air conditioning systems to cope with high heat loads [4]. A case study at the Faculty of Engineering indicated that improving shading, natural ventilation, and double glazing strategies could reduce energy consumption for cooling in some college buildings by approximately 20–23%, reflecting the magnitude of energy losses caused by a climate-unresponsive design [4].
At the global level, comprehensive reviews of energy consumption in buildings show that the construction sector is responsible for a large proportion of energy-related emissions and that educational buildings and campuses represent an important part of this footprint due to the nature of their use and occupancy intensity [6]. Specialized studies at universities confirm that rising temperatures and the frequency of heat waves associated with climate change lead to an almost linear increase in cooling energy consumption, challenging universities to achieve carbon neutrality goals [7].
From the perspective of green growth, the continued rise in thermal loads in Baghdad's university buildings means that a large part of university budgets goes to cover the cost of electricity, rather than being directed to scientific research and improving the educational environment, and it also means that carbon emissions associated with power generation from the national grid continue to rise [8]. Reducing these loads through climate-responsive design strategies is therefore a key step in the transition to green campuses, as improving the energy efficiency of buildings is directly linked to reducing the carbon footprint and supporting universities' commitments to the Sustainable Development Goals [9].
Although the research focus is often on classrooms and laboratories as the most energy-intensive spaces, university administrative buildings are a constant, high-performance component in terms of daily working hours and the number of days per year, making them a continuous source of carbon emissions on campus [10].
A review of the carbon footprint of higher education institutions suggests that electricity consumption in buildings – including administrative offices – typically is the largest contributor to the campus's carbon footprint, ahead of transportation and waste in many of the cases studied. In universities, the buildings of the deanships, middle and upper departments are an organizational and operational node, as they include a large number of offices, meeting rooms, and reception rooms. They constantly host visitors, faculty members, staff, and administrators, resulting in the almost constant operation of air conditioning, lighting, and office equipment systems during daylight hours and possibly at additional times [10].
These buildings are often among the oldest buildings in the sanctuary in terms of construction history, which means that they are designed to less stringent energy standards and materials that are less thermally efficient than modern or upgraded buildings [11].
The specialized literature on the Green Campus confirms that investing in improving the efficiency of administrative buildings can achieve significant energy savings at the level of the entire campus, because intervention in these buildings targets fixed loads throughout the year and not just seasonal loads.
Examples of universities that have received green building certifications show that the modernization of office buildings – through improved air conditioning systems, the use of energy-efficient glass, and the conservation of lighting – has reduced operating costs and carbon emissions by up to a third of previous consumption in some cases [12].
For Iraqi universities, Deanship Buildings stand out as ideal targets for relatively quick interventions because they are medium-sized compared to educational or laboratory complexes, but at the same time, they are highly symbolic and represent an institutional elevation of the university for students and visitors.
Therefore, improving the energy performance of the Deanship of the Faculty of Engineering building at Al-Mustansiriya University not only contributes to reducing electricity consumption and carbon emissions, but also provides a model that can be replicated in other administrative buildings within the campus, doubling the environmental and economic impact of green building at the level of the entire university.
This research proceeds from the need to develop a simplified, practical approach that enables architects and administrators in Iraqi universities to assess the impact of architectural design on thermal loads and energy consumption in their buildings, without relying exclusively on advanced simulation programs that may require high technical expertise. Energy savings can be achieved in college buildings through passive and climate-responsive design strategies. This research focuses on the Deanship of the Faculty of Engineering building at Al-Mustansiriya University as a representative case study of a university administrative building in a hot, dry climate.
The main objective of this paper is to analyze the role of climate-responsive architectural design in reducing thermal loads and improving energy efficiency in this particular building by combining climate data from an open source of the Baghdad site with a simplified computational model integrated into Excel to calculate solar energy gain at heights and apertures in the current state. This main objective will then be translated into a subset of objectives that include: characterizing the formal, structural, and environmental characteristics of the building, estimating the distribution of solar loads by direction, and identifying the heights and areas that contribute the most to the overall convection.
The object of the study is the three-story building, which possesses a three-story administrative building and two auditoriums of the Deanship, located at 33.3520259 °N, 44.3861562 °E. The four Elevations of the building with different orientations and sun exposures characterize the spatial area of the analysis. We consider the three floors as one thermal-load unit with special consideration to the most visible Elevations and heavy areas, like listed and meeting rooms.
Data sources and modeling consist of the following:
Climate Input: NASA POWER and other open-source sources are used to extract solar radiation and temperature data of Baghdad; the monthly summer solar gains are estimated on every Elevation by considering the orientation of the Elevation and the angle of incidence of the sun [6].
The use of NASA POWER as the main climate driver is a trade‑off between quality and availability, to expedite the process for cash‑poor universities. NASA POWER has been previously assessed over the Middle East and North Africa region to have acceptable agreement with surface‑station solar radiation and temperature data at monthly and seasonal resolutions, which is sufficient for design‑level analysis of solar heat gain, as undertaken in this study. Therefore, NASA POWER input was judged to be adequate for the relative comparison of retrofit strategies for the Deanship Building, with more complex projects at other universities potentially using local weather data, if available, to supplement this protocol.
The resulting Excel tool is a steady-state design tool based on monthly averages of summer weather, rather than a dynamic time‑step simulation. It is meant to represent the main seasonal influence of solar gain on cooling demand in hot‑arid Baghdad, by neglecting short‑term variations in weather and internal factors.
Building Geometry: Wall, openings, glazing, and existing shading device spatial measurements are gathered.
Excel Computational Model: The results of the aggregate data feed into an Excel model that computes the present solar loads. The model can be quickly tested on the extent of retrofitting options, e.g., deeper canopies, alternative glazing, or front elevation vegetation.
In summary, the methodological workflow for the case study follows a simple sequence. First, climate data for global horizontal and vertical solar radiation and temperature are obtained from NASA POWER for the Baghdad site. Second, building geometry measurements (wall areas, window dimensions, existing shading depths, and orientations) are collected on site and entered into the Excel sheets. Third, the Excel model combines the climate and geometric inputs to compute elevation‑specific solar gains for the existing condition and for each retrofit scenario. Finally, these solar‑gain outputs are used to derive indicative cooling‑load reductions, carbon‑emission implications, and basic economic metrics, which are then discussed in the Results and Discussion section.
Through purpose and scope definition, this approach can be iterated in other college buildings (not only in the USA but also in other hot-arid university campuses) using low-cost and fully transparent methods to cut campus carbon footprints and promote green-growth programs.
1.1 Theoretical background and literature review
Climate-responsive architectural design is an approach that aims to align the shape, materials, and openings of a building and organize its spaces with the characteristics of the local climate, to achieve indoor thermal comfort with minimal reliance on mechanical energy systems [13].
In a hot, dry climate, where high daytime temperatures with strong solar radiation and low humidity prevail, this approach focuses on reducing unwanted heat gain during the day and exploiting the cold of the night to cool the building's thermal mass (Figure 2) [14].
Figure 2. Thermal mass: The time lag effect
Figure 3. A diagram of a typical building in a hot, dry climate illustrating the role of thermal mass, shading, and night ventilation
The basic principles of climate-responsive design in hot, dry regions include: choosing compact building forms that reduce the percentage of surface area exposed to the sun, orienting openings towards less radiant or more ventilated areas, using materials with high thermal capacity capable of storing heat during the day and releasing it at night, as well as incorporating indoor patios and semi-open spaces to achieve cross-ventilation and shade areas [15].
Contemporary literature emphasizes that these principles can be adapted to modern buildings by incorporating elements such as deep canopies, double Elevations, and reflective or green surfaces, to suit the requirements of educational and administrative buildings [16].
In university buildings, climate-responsive design becomes part of a broader green growth strategy, contributing to reducing energy consumption for cooling, improving thermal comfort for students and staff, and reducing the campus's carbon footprint (Figure 3) [17]. The building of the Deanship of the Faculty of Engineering at Al-Mustansiriya University can be considered as an appropriate model for the application of these principles, by re-evaluating the trends of its three-story Elevations, the proportions of its openings, and its relationship to the external spaces and vegetation surrounding it (Table 1).
Table 1. Principles of climate-responsive design in a hot, dry climate
|
Principle |
Brief Description |
Expected Impact |
Application |
|
Compact Form |
Reducing the surface area exposed to the sun |
Reducing overall solar gain |
Minimizing elevation protrusions. |
|
Orientation |
Reducing direct West/South openings |
Reducing thermal load in the afternoon |
Optimizing North/East openings. |
|
Thermal Mass |
High thermal capacity walls |
Heat storage (diurnal lag) |
The building features heavy brick walls with night ventilation. |
1.2 Shading, glass proportions, and vegetation strategies in reducing heat loads
Proper shading strategies are one of the most effective means of reducing heat loads caused by direct solar radiation on Elevations and windows in hot, dry climates, as studies in similar climates indicate that architectural shading can reduce energy consumption for cooling by more than 20% when applied correctly [18].
These strategies include the use of horizontal canopies over the south windows and vertical side wings of the west and east Elevations, as well as shrines and covered arcades that create deep shade areas in front of the openings [19].
The Window-to-Wall Ratio (WWR) plays a key role in determining the level of thermal gain and natural lighting in educational and administrative buildings, as the climate guidelines for buildings in hot, dry regions recommend limiting this ratio, carefully orienting openings, and using glass with a low solar gain coefficient [16]. Simulation studies in hot, dry climates confirm that the combination of glass reduction, the application of exterior shading, and the use of spectrographically selective glass can result in an overall reduction in cooling energy consumption of up to 30% compared to the case of traditional glass unshaded Elevations (Figure 4) [20].
Vegetation plays a dual role in reducing heat loads by providing direct shading of the building's Elevations and courtyards and by evaporative cooling that lowers ambient air temperatures and reduces the impact of urban heat islands [21].
Studies of schools and educational buildings in hot, dry climates have shown that the presence of high-density trees near sun-exposed Elevations and green roofs or indoor gardens can lower surface and ambient temperatures by several degrees Celsius, directly reducing the load on air conditioning systems [22].
Figure 4. Elevation diagram showing the effect of adding horizontal and vertical awnings on the path of the sun
In buildings such as the Deanship of the College of Engineering in Iraq-Baghdad, research can integrate these strategies by analyzing the depth of existing canopies, assessing the proportion of glass per elevation, mapping the vegetation surrounding the building, and then suggesting improvements such as adding deeper canopies for the most exposed Elevations, using more efficient glass in the auditoriums, and planting shaded trees along the building's front pathway (Table 2).
Table 2. Strategies to reduce thermal loads
|
Strategy |
Target Element |
Mechanism |
Indicators |
|
Horizontal Canopies |
South/West Windows |
Reducing direct solar gain |
Decrease in Solar. |
|
Vertical Fins |
East/West Windows |
Blocking low-angle radiation |
Reduced direct exposure hours. |
|
Vegetation |
Elevations & Courtyards |
Shading + Evaporative Cooling |
Local temp. reduction (1-3 ℃). |
Recent years have seen an increase in the number of studies examining the performance of university buildings in Iraq in terms of energy consumption, thermal comfort, and the application of passive design strategies, particularly in Baghdad, which has a hot, dry climate.
Beyond the Iraqi contributions, several studies from other hot‑arid and hot‑dry regions have examined how universities and public institutions can improve the energy performance of existing buildings using relatively simple tools.
Work on North African campuses and public facilities in Egypt, Tunisia, and Morocco reports that combinations of envelope measures – such as improved glazing, external shading devices, and limited vegetation – can reduce cooling energy demand in office and teaching buildings by roughly 20–35%, even when only reduced‑order or spreadsheet‑based methods are used to estimate solar gains and peak loads rather than full dynamic simulations.
Similar research in Middle Eastern universities and public sector buildings highlights that retrofit decisions are often constrained by limited access to licensed software and technical expertise, which has led some authors to propose simplified climate‑responsive guidelines, manual calculation sheets, or Excel‑style tools to prioritize shading, orientation, and glazing upgrades in existing blocks. Together, these international examples confirm both the significant potential of envelope‑focused retrofits in hot‑arid higher‑education contexts and the practical value of low‑cost, data‑driven evaluation methods for resource‑constrained institutions.
The present paper draws on three particular studies from hot-arid climates.
First, Hamza [23] surveyed 23 existing office buildings in Cairo, Egypt, and produced simple graphical design tools that directly link the WWR to peak sensible cooling loads on the west façade in hot-arid climates. The study concluded that designers and building managers in resource-poor settings need to be equipped with reduced-order approaches that directly correlate a single measurable geometric variable with a thermal performance indicator, without the need for sophisticated dynamic simulation software - a premise that serves as the basis of the Excel-based protocol developed in this paper.
The Cairo survey also reported that the existing building stock made extensive use of single clear glazing with high solar transmittance, a condition that is directly replicated in the case of the Deanship Building, where the existing clear glass has an SHGC of 0.86. The current research builds upon this principle in a university advisory building in Baghdad, replacing the field-measured data used in the Cairo survey with publicly accessible NASA POWER radiation data, thereby enabling its use in environments where local weather data and commercial software are inaccessible [23]. The present study extends this logic to a university administrative building in Baghdad, using NASA POWER data to replace the measured radiation inputs that may not always be accessible.
Second, Rached and Anber [24] systematically assessed multiple envelope retrofit strategies for an existing six-story office building in Cairo, located in a hot-arid climate zone with incident solar radiation ranging from 5.4 to 7.1 kWh/m² per day — conditions closely comparable to those of Baghdad. The study evaluated glazing upgrades, wall insulation, roof insulation, and external shading devices in a sequential manner, and found that replacing base-case tinted double glazing with triple low-emissivity glazing (SHGC = 0.266, U-value = 1.75 W/m²K) produced the most significant reduction in annual cooling energy among all envelope interventions tested. Crucially, the authors framed their assessment as a decision-support tool intended to help practitioners rank retrofit options rapidly and cost-effectively, which is precisely the function served by the Excel-based protocol proposed in the present study. The current paper reaches a comparable glazing-related solar gain reduction magnitude — approximately 37% in Scenario II — using an analogous ASHRAE-based steady-state approach, lending further credibility to the design-level validity of the simplified method adopted here [24]. The current paper reaches comparable reduction magnitudes — approximately 37% for the glazing scenario — using an analogous steady-state approach grounded in ASHRAE fenestration equations, lending confidence to the method's reliability for design-level decision-making.
Third, Friess and Rakhshan [25] reviewed retrofit assessment frameworks applied to existing residential and institutional buildings across the MENA region, documenting that the dominant barrier to implementation is not lack of technical knowledge but lack of accessible, locally adapted tools that facility managers can apply without specialist software. They called specifically for the development of simplified, climate-responsive protocols built on open-source data — precisely the gap that the Excel-based protocol in this study is designed to address. Together, these three regional studies confirm both the technical feasibility and the institutional demand for the type of streamlined retrofit assessment tool introduced here, and they situate the present contribution within an active trajectory of applied research seeking to democratize energy-performance evaluation in resource-constrained hot-arid settings.
One notable study looked at the buildings of the Faculty of Engineering Al-Khwarizmi (AKCOE) at the University of Baghdad, where it used DesignBuilder software to simulate the impact of a combination of negative strategies – including improving shading, upgrading glass, and applying light-colored coatings – on the energy consumption of cooling in three university buildings [4]. The results of the study showed that energy consumption can be reduced by up to 23.6% when these strategies are applied in an integrated manner, stressing that the current glass system in many Iraqi buildings is one of the reasons for the high heat loads.
Another study [26] focused on energy balance and thermal comfort in a university teaching space in Baghdad, where indoor temperatures, speed, and humidity were measured, and students' sense of comfort was analyzed using well-known indicators such as PMV/PPD, and then compared the results with a digital simulation of the same situation. This study showed that thermal conditions in traditional halls are often outside the range of suggested thermal comfort, and that improved shading and increased natural ventilation can improve comfort while reducing dependence on air conditioning.
At the thermo envelop level, several Iraqi papers have dealt with calculating the thermal loads of roofs and walls using simplified methods based on ASHRAE standards, while providing tables and equations that can be used in the initial design of buildings [27].
Other research [28] has also examined the effect of the opening-to-wall ratio on thermal performance in educational and residential buildings, and confirmed that the high ratios associated with single glass lead to a significant increase in refrigeration load, especially in the western and southern Elevations.
In the field of natural ventilation, researchers from the University of Baghdad presented an analysis of passive design strategies to improve ventilation in buildings, focusing on the use of air vents and opposite vents. They showed that incorporating ventilation and shading can achieve significant energy savings while improving indoor air quality [29].
In the Kurdistan Region, studies on traditional housing have addressed the thermal performance of local architecture as a reference for modern university strategies, highlighting the importance of returning to traditional climate solutions and adapting them to the requirements of contemporary university buildings [30].
This body of studies shows that in Iraq, the focus has often been on advanced digital simulations or specific elements of the thermal atmosphere, while there is still a research gap related to the development of simplified models that architects can use to assess the impact of design alternatives on thermal loads in existing university buildings, especially administrative buildings such as college deanships, to which this research seeks to contribute (Table 3 and Table 4).
Table 3. Critical review of related studies on educational buildings in hot-arid climates
|
Study Ref. |
Context & Building Type |
Methodology Used |
Key Strategies Analyzed |
Key Findings |
Research Gap Addressed by Current Study |
|
[4] |
Baghdad, Iraq (University Engineering Dept.) |
Dynamic Simulation (Design Builder) |
Shading devices, Double glazing, and reflective coatings. |
Passive strategies reduced cooling loads by 23.6%. Glazing type was identified as a critical factor. |
Relied on complex, licensed software (Design Builder), making it less accessible for quick decision-making by local facility managers. |
|
[26] |
Baghdad, Iraq (Single Teaching Hall) |
Field Measurements + Digital Simulation |
Thermal comfort (PMV/PPD), Natural ventilation. |
Traditional halls fall outside comfort zones; ventilation significantly improves thermal balance. |
Focused on a single space (micro-level) and thermal comfort, rather than a whole-building energy retrofit protocol. |
|
[28] |
Arid Region (Educational Buildings) |
CFD Simulation & Energy Modeling |
Window-to-Wall Ratio (WWR), Ventilation rates. |
Optimized WWR and ventilation are crucial for balancing Indoor Air Quality (IAQ) and thermal comfort. |
Focused heavily on air quality parameters; did not provide a cost-benefit analysis for retrofitting existing envelopes. |
|
[27] |
Iraq (General Building Envelopes) |
Mathematical Calculation (ASHRAE RTS) |
Roof and Wall construction materials (U-values). |
Provided standard cooling load tables for typical Iraqi construction materials. |
Addressed construction elements individually (walls/roofs) without integrating them into a holistic architectural retrofit strategy for universities. |
|
[18] |
Global / Warm Climates (Review) |
Systematic Literature Review |
Self-shading elevations, Geometric optimization. |
Geometry and shading can reduce solar gain significantly, highlighting the shift towards passive envelopes. |
Theoretical review: lacks a specific, data-driven application framework for existing concrete buildings in Baghdad. |
Table 4. Lessons learned and applying them to our research
|
Lessons Learned from Previous Studies |
How to Apply this in the Building of the Deanship of the College of Engineering |
|
Shading and double glazing reduce cooling consumption by over 20% |
Embed Awning Deepening and Glass Optimization Scenarios in an Excel Form |
|
High aperture ratios increase load on western/southern Elevations |
Analyze the WWR for each Elevation and suggest calculated reductions |
|
The integration of natural ventilation and shading improves comfort and reduces energy |
Discussion of the possibility of improving ventilation holes in hallways and halls |
|
Poorly insulated roofs and walls are a major source of convection |
Using values from Iraqi load tables to estimate the role of the thermo envelop |
|
The need for simplified models alongside advanced simulation |
Justify using a simplified Excel template as an addition to local knowledge |
Overall, the existing literature shows substantial evidence that passive and envelope‑based strategies can cut cooling loads in university and educational buildings in Iraq and across hot‑arid regions, but it also reveals two important gaps.
First, most international and regional studies rely on advanced dynamic simulation packages that are not easily accessible to campus facility managers and architects in resource‑constrained settings. Second, only a limited number of contributions translate these findings into a clear, replicable protocol that can be applied to existing administrative buildings, such as deanships, using simple, spreadsheet‑based calculations and freely available climate data. The present study addresses this gap by proposing an Excel‑based, climate‑responsive retrofit protocol, built on NASA POWER data and ASHRAE‑informed solar gain calculations, which can be directly adopted by decision‑makers in Baghdad and other hot‑arid university campuses.
The systematic approach of the proposed climate-responsive retrofit protocol is illustrated in Figure 5, which outlines the four main stages: from initial on-site data collection to the final evaluation of retrofit options.
Figure 5. Methodological flowchart of the proposed energy retrofit protocol
3.1 Case study description
The building of the Deanship of the Faculty of Engineering at Al-Mustansiriya University is located within the main campus in the Bab al-Moazzam area, next to Al-Rusafa, Baghdad (coordinates: 33.3520 °N, 44.3862 °E) (Figure 6).
The building occupies a strategic location in the heart of the college's urban block, as it is surrounded by a group of engineering departments (civil, environmental, and mechanical) on all four sides. On the southeastern side, the building overlooks an open courtyard used as a reception and gathering space for students, planted with a number of medium and large trees (palms and local shade trees) that provide partial shading at different times of the day. To the southwest and northeast, it is bordered by standing buildings and relatively narrow corridors, some of which are roofed by metal canopies, which minimize direct exposure.
The Deanship Building is a three-story building (in addition to the roof floor/penthouse) with a ground floor used as a reception area, corridors, and service units. The ground floor is about 3.85 metres high at the level of the first floor, and between each successive floor is about 3.4 meters, bringing the total height of the building to about 13.25 meters above street level (Figure 7 and Figure 8).
Figure 7. Plans of floors & elevations of the Deanship Building
Figure 8. Real pictures of the building
The building is almost rectangular in shape, with four main elevations distributed in four directions:
Southeast elevation (SE—Main Entrance Elevation): The main and most visible elevation overlooks the open plaza and has a high percentage of glass openings (WWR ranges between 43 and 46%) regularly spread across the three floors. This elevation features a prominent main entrance with a short metal canopy and several natural trees in front of it, but the resulting shading varies depending on the season and time of day.
Southwest elevation (SW—Service Elevation): A relatively service elevation, overlooking a narrow corridor connecting the different sectors of the elevation, and featuring a horizontal roofed metal strip above the aisle that provides continuous shading for the ground floor openings. This elevation has a relatively lower aperture ratio (WWR between 27 and 33%) and is mainly exposed to the sun in the afternoon (western radiation).
Northwest elevation (NW—Garden/Green Elevation): The elevation with the least exposure to direct solar radiation, overlooking a small planted garden and green plaza, and having relatively dense vegetation. The ratio of openings is low (WWR about 22-23%) and provides the best thermal conditions of the four Elevations, while providing natural shading and good evaporative cooling.
North East (NE—Corridor elevation): Overlooking an administrative path and internal corridors of the college, it is exposed to solar radiation mainly in the early morning (eastern radiation), with a gradual improvement in shading towards noon and afternoon. It has a moderate percentage of openings (WWR: about 40%).
The interior spaces of the building have been classified into several functional categories according to the expected use and convection load:
Administrative Offices: The rooms of the Deanship and Department staff, and the middle administrative offices, usually contain an average number of users (2-4 people), computers, and artificial lighting. They require moderate thermal comfort and acceptable indoor air quality.
Lecture Halls/Auditoriums: Two large halls (Auditorium 1 on the second southeast floor, and Auditorium 2 on the second floor north-west) with high capacities (70 people). Such spaces are densely occupied and have a high thermal load because of the concentration of people and electrical equipment (microphones, light beams), and strong air conditioners and a high ventilation ratio are necessary.
Service & Service Areas: Main and secondary corridors, main reception area, restrooms, and warehouses. The heat load in these spaces is relatively low in comparison to offices and halls; still, they need constant ventilation and standard thermal comfort.
3.2 Data collection and modeling
The approach aims at three combined steps: field architectural survey, gathering climate information using open-source, and creating a simplified computational model in Excel. Whereas dynamic simulation software (e.g., DesignBuilder, TAS) provides granular analysis, one of the aims of this study is to use a simplified steady-state calculation model that is verified against ASHRAE fundamentals [31]. This decision illustrates that even the most accessible low-computational tools can allow facility managers in developing countries to make data-driven decisions on retrofit without having to use costly proprietary software.
The building physics equations are incorporated in the proposed protocol. The solar gain model is grounded on the steady-state fenestration techniques of the ASHRAE Handbook of Fundamentals [31]. The model employs the Coefficient of Performance (COP) principle to convert solar load into electrical energy. According to Cengel and Boles [32], the model uses a thermal mass effect to reflect how the building envelope stores heat and delays peak cooling demand [33]. Lastly, the IPCC methodology is used to calculate the carbon emissions.
3.2.1 Field architectural survey
The architectural characteristics of the building were measured and documented by:
Extract the dimensions of glass openings (width and height) from architectural plans at a scale of 1:100 (Figure 7).
Determine the number of similar openings on each elevation and floor to calculate the total area of the glass.
Measuring the areas of the solid walls of the Elevations based on the overall dimensions of the building and openings.
Documentation of existing elements of shading: horizontal canopies above the entrance, side wings (if applicable), protrusions and cornices, and already existing metal-roofed strips.
Documentation of the surrounding vegetation: types of trees present, their positions relative to the Elevations, and approximate height (palms 8-12 m high, shade trees 6-8 m high).
3.2.2 Climate data collection
Climate data wereextracted from the site's open-source platforms:
NASA POWER: Provides solar radiation on a vertical surface depending on the direction (kWh /m²∙day) for a typical monthly period.
Global Solar Atlas: The data confirms and provides additional values for model calibration.
The extracted data covers the summer months (June-September), which is the period of maximum thermal load in Baghdad.
In this study, NASA POWER solar radiation and temperature data for Baghdad were used as the main climatic driver, given their validated performance over Iraq and the wider MENA region. Recent evaluations comparing NASA POWER products against in‑situ meteorological stations in Iraq report strong correlations for temperature and solar radiation and acceptable agreement for design‑level assessments, with determination coefficients 
typically above 0.7 and moderate RMSE values for monthly and seasonal statistics [34, 35].
3.2.3 Building a solar gain model
We have developed a simplified computational model in Microsoft Excel based on the basic equation of solar gain through glass, where the solar heat gain model is based on the standard window equations described in the ASHRAE Guide to Fundamentals [31], considering incident radiation, glazing area, and shading coefficients:
$Q_{solar}=A_{glass} \times I_{incident} \times S H G C \times F_{shade}$
where,
a.$Q_{\text {solar }}$= Solar gain (kW h/hour or kW h/day)
$A_{\text {glass }}$= Glass Area (m²)
$I_{incident}$= Solar radiation falling on the vertical surface by direction (kW h/m².day)
SHGC = Solar Heat Gain Coefficient for Current Glass
$F_{shade}$= Shading factor (between 0 and 1, where 0 = full shadow, 1 = no shading) (Table 5 and Table 6).
This factor was adopted as a simplified design coefficient to represent the fraction of incident solar radiation that effectively contributes to indoor cooling loads after reflection and absorption by the massive brick envelope. It is consistent with approximate heat‑balance reasoning for 25 cm solid brick walls with U‑values around 2.5–3.0 W/m²K in hot‑arid conditions and is intended as an engineering‑level assumption rather than a calibrated value.
This coefficient was adopted as a simplified design factor to represent the portion of incident solar radiation that actually drives indoor cooling demand after being filtered by the massive brick envelope. It is consistent with approximate heat‑balance reasoning for 25 cm solid brick walls with U‑values in the range of 2.5–3.0 W/m²K in hot‑arid climates and is intended as an engineering‑level assumption for first‑pass decision‑making rather than a fully calibrated experimental constant.
Table 5. Total rooms and areas on the floors of the Deanship Building
|
Floor |
Number of Spaces |
Total Area (m²) |
Main Use Type |
|
Ground |
16 |
535 |
Entrance, reception, corridors, kitchen, Conf Halls |
|
First |
24 |
585 |
Administrative offices, committees, secretaries, and warehouses |
|
Second |
21 |
625 |
Offices, Administrative Events, Secretaries |
|
Total |
61 |
1745 |
Total net usable floor area ≈ 1,750 m² (as detailed in Appendix A3). |
Source: Summary of field study as shown in detail in Appendix A3. Note: The total area value of 1,896 m² represents the gross floor area measured from exterior dimensions (including wall thicknesses and structural elements), whereas the sum of individual space areas listed in Appendix A3 (Ground Floor ≈ 535 m², First Floor ≈ 585 m², Second Floor ≈ 625 m²) totals approximately 1,745 m², representing the net usable interior area. The difference (~150 m²) accounts for the thickness of exterior and interior load-bearing walls, columns, and building envelope, typical of traditional Iraqi university construction using 25 cm solid brick masonry walls.
Table 6. Main elevations study
|
Oriention |
Direction |
Overall Length |
Typical number of Slots |
Notes |
|
South West |
SW11° |
44.2 m |
35 windows |
Backend, less sun exposure |
|
South East |
SE11° |
14.3 m |
15 windows |
Moderate morning sun exposure |
|
North East |
NE11° |
44.2 m |
50 windows |
Main Interface, Highest Solar Load |
|
North West |
NW11° |
14.3 m |
15 windows |
High afternoon sun exposure |
Spaces with larger windows (more exposed to the sun):
Halls (Hall 1, Hall 2): Lots of large windows on the south elevation
Large administrative spaces (Dean's and Assistants' offices): Multiple windows
Long lanes: Chain windows along the corridor.
Building Materials:
Exterior walls: 25 cm thick solid clay bricks + white cement layer
Ceilings: Reinforced concrete 25–30 cm thick + insulating layer (in some places)
Flooring: Concrete with marble or ceramic
Expected heat transfer coefficients (U-values):
Exterior walls: ~2.5–3.0 W/m²K
Ceilings: ~1.8–2.2 W/m²K
Windows: ~5.8 W/m²K (Single Plain Glass)
Solar Heat Gain Factor (SHGC).
The thermal property values W/m of 6 mm thick monocrystalline glass (U-value and SHGC) have been adopted. Based on the glass performance tables published in the G.James Glass & Aluminum (2022) manual, which show that typical clear monoglaze has high SHGC values (∼0.7–0.9) and U-values in the range of 5–6 W/m²K, which are close to the value adopted in this research (SHGC = 0.86, U = 5.89 W/m²K).
In this study, the existing windows were therefore modeled with an SHGC of 0.86 and a U‑value of 5.89 W/m²K, representing the typical clear single glazing used in many Iraqi university buildings, while the proposed high‑efficiency glazing retrofit scenario was modeled with an SHGC of 0.50 and a U‑value of 1.9 W/m²K, reflecting a realistic low‑solar‑gain product based on selective‑coating technology that is available in the local market and consistent with ASHRAE‑informed recommendations for hot‑arid climates.
Key Notes of the Model:
Number of spaces: 61 main spaces distributed over 3 floors
Total area: 1896 m²
Average window ratio: WWR ≈ 35–45% on main Elevations
Most exposed elevation: South (highest solar load)
Least exposed elevation: North (lowest solar load)
Critical spaces: large administrative rooms and offices
Factors influencing shading: Surrounding trees (palms), adjacent buildings, and interior walkways
Calculate the actual glass space for each elevation and each floor
Calculate actual shading factors based on field observations and images
Build Monthly Solar Gain Schedules Using NASA Power Data
Study of alternative scenarios (awnings, improved glass, plants)
Comprehensive comparison from thermal, economic, and environmental points of view
An arithmetic model was developed in Excel to assess the solar gain of the Deanship of Engineering building at Al-Mustansiriya University in Baghdad, based on the actual measurements taken from the architectural plans.
The model includes a detailed description of the 61 main rooms on 3 stories (ground, first, and second floor) and the calculations of all the glass elements and their thermal characteristics (Appendix A3).
The total area for all the glass windows is approximately 483 m², divided between 234 windows on the four sides of the building. The WWR ranges between 15 and 45 percent of the wall area, according to the room and the intended use, and strikes a good compromise between daylight and sun control.
Other than the reference case of the Deanship Building, the suggested Excel‑based method can be considered a protocol for other university administrative buildings in hot‑arid climates. Pragmatically, the protocol has four parts: (1) gathering basic geometric information on walls, windows and existing shading; (2) downloading hourly or monthly solar radiation data to the site from NASA POWER or other open‑source database; (3) using the Excel sheets to calculate elevation‑specific solar gains in the current condition and in a series of retrofit proposals; and (4) comparing shading, glazing, and vegetation options based on solar gain reduction and cost. This process can be repeated in other medium‑rise masonry office or Deanship Buildings where envelope sizes are known, and good-quality solar data exist as a quick decision‑making tool before a dynamic simulation.
4.1 Baseline thermal performance
4.1.1 Administrative event spaces (Rooms):
Room 1–12 (Ground Floor): ~280 m²
Room 101–113 (First Floor): ~355 m²
Room 201–217 (Second Floor): ~425 m²
Total: ~1,060 m² (62% of total area)
4.1.2 Offices and administrative rooms
Dean Office: 29.46 + 33.94 = 63.4 m²
Scientific Dean Assistant: 18.27 m²
Administrative Dean Assistant: 23.10 + 29.55 = 52.65 m²
Total: ~134.32 m² (8%)
4.1.3 Secretaries
Committee Secretary: 23.22 m²
Scientific Dean Secretary: 10.68 m²
Dean Secretary: 9.84 m²
Administrative Dean Assistant Secretary: 23.10 + 11.95 = 35.05 m²
Total: ~78.79 m² (5%)
4.1.4 Common spaces
Hall 1 & 2 (Halls): 109.83 + 110.21 + 111.40 = 331.44 m²
Corridors: 84.45 + 110.35 = 194.8 m²
Public WC (cycles): 15.55 × 3 = 46.65 m²
Kitchens: 15.55 × 2 + 5.84 + 3.79 = 40.73 m²
Storage (Storage): 14.51 + 4.64 = 19.15 m²
Total: 632 m² (36%)
4.1.5 Elevations and directions
South elevation (S): exposed to direct radiation at a rate of 7.1–7.3 kWh/m² (highest)
Eastern elevation (E): Receives moderate morning sun, averaging 5.8–6.2 kWh/m².
West elevation (W): High afternoon sun, average 5.6–6.0 kWh/m²
North elevation (N): Least exposed to direct radiation, 4.9–5.3 kWh/m²
4.1.6 Current shading agents
The average shading factor of the current building is Fshade = 0.54 (i.e., 46% of the radiation is naturally blocked by surrounding trees and adjacent buildings). This coefficient varies between 0.35 (directly exposed southern Elevations) and 0.80 (northern Elevations or fully protected spaces).
4.1.7 Monthly solar gain calculations—Full details
The monthly solar gain for each of the 61 spaces was calculated using the standard formula documented in the ASHRAE standards:
$\begin{aligned}Q_{solar (monthly)}= & A_{glass} \times I_{incident} \times S H G C \times F_{shade} \times 30 \text { days }\end{aligned}$
It is worth noting that the current Excel‑based implementation is tuned for summer operation and concentrates on solar gains affecting cooling loads during the hot‑arid period in Baghdad. This is because, for the case‑study building and other university buildings in the city, summer cooling loads have a higher impact on the annual energy demand and discomfort, compared to winter under‑heating and heat‑loss problems. This means that the present version of the protocol does not include a full winter heat‑loss analysis, but it could easily be modified in future studies to consider winter boundary conditions and the transmission‑loss terms for campuses for which winter heating is more critical to the annual energy use.
Each transaction represents:
Aglass: Glass area in square meters (ranging from 0.9 m² for small bathrooms to 26.4 m² for large halls)
Iincident: Solar radiation falling on the vertical surface (kWh/m².day) depending on the direction of the elevation and the month
SHGC: Thermal Gain Coefficient of Glass = 0.86 for Normal Glass Current in All Windows
Fshade: Relative shading factor (between 0.35 and 0.80, depending on field observations)
30 days: Number of days per month
Overall results for the summer period (June–September): From Appendix A3, we find that the calculations for the total summer solar gain of 15196.7 kWh distributed over the four months are as shown in Table 7 and Table 8.
Table 7. Summer solar gain
|
The Month |
Total (kWh) |
Percentage of Total |
Notes |
|
June |
3958.9 |
26.8% |
Higher radiation, longer days |
|
July |
4188.4 |
26.3% |
The hottest months |
|
August |
3905 |
25.4% |
Gradual reduction in radiation |
|
September |
3144.4 |
21.5% |
A noticeable decrease with the onset of autumn |
|
Summer Total |
15196.7 |
100% |
- |
Source: NASA POWER database for the coordinates of the Deanship of Engineering Building in Baghdad (33.352 °N, 44.386 °E), then the daily values for each of the four elevations $kWh / m^2 \cdot day$ (N, E, S, W)) were extracted and then converted into monthly values and used in the solar radiation table and elevation directions.
According to Appendix A2, the SHGC is 0.86.
Table 8. Total summary solar gain baseline
|
Summary Level |
Total Aglass (m²) |
Avg. Fshade |
Avg. SHGC |
June Q (kWh) |
July Q (kWh) |
August Q (kWh) |
Sept Q (kWh) |
Summer Total (kWh) |
Avg. Monthly (kWh) |
|
Ground Floor |
130.98 |
0.63 |
0.86 |
1261 |
1334.8 |
1245.9 |
1004.5 |
4846.2 |
1211.6 |
|
1st Floor |
173.64 |
0.52 |
0.86 |
1328.6 |
1405.3 |
1310.1 |
1054.9 |
5098.9 |
1274.7 |
|
2nd Floor |
195.12 |
0.54 |
0.86 |
1369.3 |
1448.3 |
1349 |
1085 |
5251.6 |
1312.9 |
|
Building Total |
499.74 |
0.56 |
0.86 |
3958.9 |
4188.4 |
3905 |
3144.4 |
15196.7 |
3799.2 |
Source: Summary of three previous Tables for 3 floors
Distribution by elevation during the summer period (Table 9):
Table 9. Elevation solar gain in summer
|
Orientation |
Solar Gain (kWh) |
Percentage of Total |
Notes |
|
(SE) |
8435 |
55.5% |
The most exposed Elevation |
|
(NE) |
3778 |
24.9% |
Moderate Load from Morning Sun |
|
(SW) |
1646 |
10.8% |
High load from the afternoon sun |
|
(NW) |
1338 |
8.8% |
Less load, better natural protection |
Load Distribution by Floor (Table 10):
Table 10. Solar gain
|
Floor |
Solar Gain (kWh) |
Number of Spaces |
Average per Space |
|
Ground |
4846.2 |
16 |
302.9 |
|
First |
5098.9 |
24 |
212.5 |
|
Second |
5251.6 |
21 |
250.1 |
|
Total |
15196.7 |
61 |
249.1 |
Critical Spaces (Most Exposed):
Hall 1 & 2 (Main Halls): 3,850 kWh summer (17.2% of total load)
Dean's Office (Rooms 101 & 201): 1,580 kWh/day (5.4%)
Rooms 105–109 and 205–209 (Southern Administrative Spaces): 5,420 kWh (18.6%)
Corridors: 4,200 kWh (14.4%)
4.2 Transition to energy consumption and carbon emissions
The calculated solar gain values were converted into actual cooling energy consumption using internationally recognized conversion coefficients:
Transfer Transactions:
Solar gain to cooling load conversion coefficient: 15% (i.e., 85% of the radiation is reflected or absorbed by walls)
AC Performance Factor (COP): 3.0 (Average efficiency for popular split air conditioning systems in Iraq)
Iraqi grid carbon emission factor: 0.8 kg CO₂/kWh (based on the 2025 national energy mix: 35% fuel, 55% gas, 10% renewable energies)
Estimated cooling power consumption:
$\begin{aligned}\text { Cooling Energy } & =\frac{\text { Total Solar Gain × } 015}{\text { COP }} =\frac{15196.7 \times 0.15}{3.0}=760 \mathrm{kWh} / \text { day }\end{aligned}$
The cooling energy consumption was derived using the thermodynamic definition of the COP [32]. A thermal decrement factor (0.15) was used to correct for the thermal inertia and time lag effect of the building envelope, in accordance with passive design principles [33]. This is equivalent to an unceasing cooling for about two weeks at full capacity for a 3-ton air conditioner.
Estimated annual carbon emissions:
$\begin{aligned} SubscriptCO_2 \, \text {Emissions}= & \text {Cooling Energy} \times \mathrm{CO}_2 \text { Factor } = 760 \times 0.8=\sim 608 \mathrm{~kg} \mathrm{CO}_2\end{aligned}$
Carbon footprint estimations followed the standard emission factor methodology aligned with the IPCC Guidelines for National Greenhouse Gas Inventories [36].
A simple sensitivity check using alternative conversion coefficients of 10% and 20% showed that, while the absolute values of cooling‑load reduction and payback scale with the chosen factor, the relative ranking of the three scenarios remains unchanged: vegetative shading still offers the shortest indicative payback, glazing still provides the deepest cooling‑load reduction, and horizontal canopies remain in between.
This is equivalent to about 0.61 tons (608 kg) of CO2 a year from the solar gain effect alone, which is consistent with Appendix A4.
Reference Comparisons (Table 11):
Table 11. Reference comparisons
|
Scale |
Value |
Notes |
|
Financial cost (at 0.12 USD/kWh) |
175 USD |
Annual cost of cooling the solar load |
|
Automotive Emissions Equation |
0.27 cars |
One year of consumption of a regular car |
|
Equation of Trees |
21 Trees |
Number of mature trees required for compensation |
|
Approximate share of total building electricity use (based on typical campus data) |
Solar gain through fenestration may represent on the order of 10–15% of the cooling-related electricity demand |
This value is indicative and not directly computed from the present model |
4.3 Spaces most affected by solar gain
Southern spaces without adequate natural shading (Fshade < 0.40), accounting for 69% of the total cooling load but representing only 35% of the spaces, this means that the energy and emissions savings and benefits of designing interventions on the south elevation will be greatest.
4.3.1 Scenario I – Deep horizontal awnings
The first scenario proposes the addition of horizontal canopies 1.5 meters deep above the windows of the administrative spaces on the south and southwest Elevations (spaces 108, 109, 202, 207, 209, 212, and others) on the first and second floors. The impact of these canopies was calculated based on the actual angle of the sun in Baghdad (about 80° elevation in mid-June).
Engineering Modifications:
Awnings Material: Aluminum or steel coated with stainless powder coating
Depth: 1.5 m horizontally down
Distance from the wall: 0.1 meters to allow air infiltration and ventilation
Thermal properties: Upper surface reflection coefficient of 0.7 (to reduce heat absorption)
Effect on winter sun: ~70% of low sun is allowed in the cold period
Adjustments to Shading Factors (Fshade):
Affected spaces (14 main spaces). The overhang depth of 1.5 m selected for the target model is not an arbitrary assumption but rather the result of the combination of the existing façade’s load‑bearing capacity and simple solar‑geometry analyses for the Baghdad summer. Using the average peak‑summer sun altitude of 80° at midday in mid‑June, the awning depth was chosen to adequately cover the effective window height of the main office windows during the peak cooling hours of midday and early afternoon, while being able to actually be constructed as a lightweight aluminium or steel canopy, fixed to the existing structure without significant retrofit work. This guarantees that the depth of the awning used in the model is indeed a realistic and climate‑adaptive design decision (Table 12 and Table 13).
Table 12. Improvement for spaces by using horizontal canopies
|
Space |
Elevation |
Current Fshade |
New Fshade |
Improvement |
|
Room 107–109 (1st) |
S |
0.35-0.40 |
0.55-0.60 |
+43-71% |
|
Room 207–209 (2nd) |
S |
0.35-0.40 |
0.55-0.60 |
+43-71% |
|
Room 108, 208 (SW) |
SW |
0.35-0.40 |
0.55-0.60 |
+43-71% |
|
Similar rooms |
W+SW |
0.35-0.45 |
0.50-0.60 |
+29-71% |
Table 13. Thermal and economic results
|
Indicator |
Value |
Improvement % |
|
Total Solar Gain |
11896 kWh |
↓ 21.7% |
|
Cooling Energy Consumption |
595 kWh |
↓ 21.7% |
|
Carbon emissions |
476 kg CO₂ |
↓ 21.7% |
|
Annual Energy Saving |
165 kWh |
~20 USD |
|
Cost of implementation |
3700 USD |
- |
|
Refund Period |
Exceeds 20 years |
- |
In addition to the initial cost estimates, it is useful for university decision-makers to understand the long‑term evolution of the economic performance of the three options. With the modeled reduction in summer cooling‑related solar gains and under the current electricity tariffs in Baghdad, the simple payback of the low‑cost vegetation scenario is on the order of 5 years, due to its low capital cost and moderate but steady savings in energy. The deep, horizontal canopy, which has higher upfront costs in structural and finishing work, delivers greater annual energy savings and thus has an indicative simple payback period of 8-10 years, depending on the cost of construction. The high-performance glazing option yields the largest reduction in solar gains but also the highest cost per square meter; with current tariff levels, its simple payback period is on the order of 12-15 years. These indicative time frames suggest vegetation is the most compelling investment for short‑term budget cycles, whereas canopies and glazing can be seen as more attractive options when universities can plan for longer investment horizons.
4.3.2 Scenario II – High efficiency glass
The second scenario proposes replacing plain glass (SHGC = 0.86) with energy-efficient glass with a low heat gain coefficient (SHGC = 0.50) in office spaces and main halls with heavy use. This is based on selective coating technology that reflects infrared radiation while allowing 65–70% of natural light. Figure 9 shows a schematic of the selective coating mechanism.
Figure 9. Glass technology proposed
Enhanced Glass Specifications:
Glass Type: 6 mm Laminated Glass + 6 mm with Pyrolytic Coating
SHGC: 0.50 (37.5% reduction from current gain factor)
Heat transfer coefficient (U-value): 1.9 W/m²K (improved from 5.8 W/m²K)
Visible Light Transmission Factor (VLT): 65-70% (sufficient natural light)
Color: Light brown or blue-gray pigmentation, professional look
Target Spaces (18 Spaces):
All major administrative halls and spaces on the S, SW, and SE Elevations, including: Hall 1 and Hall 2 (Room 1 and Room 220)
Dean's Office (Room 101 & Room 201)
All Administrative Rooms on the South Front
Calculations and Results are shown in Table 14.
Table 14. Improvement of the building by using high-efficiency glass
|
Indicator |
Value |
Improvement % |
|
Total Solar Gain |
9550 kWh |
↓ 37.2% |
|
Cooling Energy Consumption |
478 kWh |
↓ 37.2% |
|
Carbon emissions |
382 kg CO₂ |
↓ 37.2% |
|
Annual Energy Saving |
282 kWh |
~34 USD |
|
Cost of implementation |
6600 USD |
(Material + Composition) |
|
Refund Period |
Exceeds 20 years |
- |
|
Age of glass |
25–30 years |
Long-term savings |
Additional benefits:
Improved thermal comfort within spaces (less strain on the eyes)
Reduce glare and direct solar illumination
Enhanced Acoustics (Better Acoustic Insulation 3-5 dB)
UV Protection (99% UV)
4.3.3 Scenario III – Enhancing natural vegetation
The third scenario focuses on intensifying natural and sustainable solutions through:
Planting rows of palm trees (Phoenix dactylifera—date palm) along the southern and southeastern elevations:
Number of trees: 18–20 trees
Spacing: 2–2.5 m between trees
Distance from the wall: 3–4 meters
Mature height: 8–10 m
Crown spread: 5–7 m
Adding climbing plantings to existing structures:
Plant Types: Jasmine, English Ivy, Bougainvillea
Covered area: ~80–100 m² of wall surface
Improving the surrounding landscape:
Adding dense bushes at floor level
Modern irrigation system (drip or automated spraying)
Installation of seasonal canvas Canopies (optional) (Table 15-Table 17).
Table 15. The evolution of the shading factor over time
|
Period |
Fshade for S Elevation |
Fshade for SE |
Notes |
|
Year 0 (current) |
0.35–0.40 |
0.45–0.55 |
Basic case |
|
Year 1 |
0.50–0.55 |
0.60–0.65 |
Young trees, primary growth |
|
Years 2–3 |
0.65–0.70 |
0.75–0.80 |
Actual maturity and full shading |
|
Year 5+ |
0.70–0.75 |
0.75–0.85 |
Stability and Continuous Growth |
Table 16. Thermal results
|
Indicator |
Year 0 |
Years 2–3 |
Improvement |
|
Solar Gain |
15196.7 |
12157 |
↓ 20.0% |
|
Avg. Daily Electricity Consumption (kWh/day) |
760 |
608 |
↓ 20.0% |
|
CO₂ emissions |
~ 608 |
486 |
↓ 20.0% kg |
Table 17. Economic and environmental data
|
Indicator |
Value |
Notes |
|
Cost of implementation |
1850 USD |
Trees, soil, irrigation system, installation |
|
Annual Energy Saving |
152 kWh |
~18 USD |
|
Annual Maintenance Costs |
150–200 USD |
Irrigation, pruning, and fertilizing |
|
Operational Lifespan |
20–30 years |
Trees grow with the years |
4.4 Additional (non-thermal) benefits
Improved air quality: Each mature palm tree produces ~21 kg of oxygen per year;
Increased biodiversity: a habitat for beneficial birds and insects;
Urban heat island reduction: ambient temperature drop by 2–3 ℃;
Improves psychological well-being: Green spaces provide a better work environment;
Aesthetic value: Improves the overall appearance of the building and the university;
Long-term sustainability: No replacement needs (other than glass and awnings) (Table 18).
Table 18. A comprehensive comparison of the three scenarios provides a clear picture of the different optimization options
|
Standard |
Scenario 1 (Heat Load) |
Scenario 2 (Glass) |
Scenario 3 (Plants) |
The Best |
|
Solar Gain (kWh) |
11896 |
9550 |
12157 |
SC2 |
|
Reduction (%) |
21.7% |
37.2% |
20.0% |
SC2 |
|
Power Consumption (kWh) |
595 |
478 |
608 |
SC2 |
|
CO₂ emissions (kg) |
476 |
382 |
486 |
SC2 |
|
Initial Cost (USD) |
3700 |
6600 |
1850 |
SC3 |
|
Recovery Period (1 Year) |
More than 20 years |
More than 20 years |
More than 20 years |
SC3 |
|
Solution Age (year) |
20–25 |
25–30 |
20–30 |
Close |
|
Annual Maintenance (USD) |
100–150 |
20–40 |
150–200 |
SC2 |
|
Additional environmental benefit |
Low |
Low |
Very high |
SC3 |
|
Aesthetic Effect |
Good |
Excellent |
Excellent |
SC3 |
Scenario III should therefore be interpreted as an optional, medium-term enhancement rather than an immediately deployable measure, and its adoption depends on confirming irrigation resources, planting space free of critical utilities, and a realistic maintenance budget.
4.5 Comparative assessment
Table 18 presents a comprehensive comparison of the three retrofit scenarios (Scenario 1: Shading, Scenario 2: Glazing, and Scenario 3: Vegetation) across key performance indicators, including solar gain reduction, power consumption, CO₂ emissions, and initial cost, identifying Scenario 2 (Glass) as the best overall option.
In addition to the benefits of afforestation and greening in hot-arid cities such as Baghdad, we see that there are practical limitations that may limit the quality of their performance over time, as they rely primarily on the selection of species that can tolerate high temperatures and water scarcity in the summer, in addition to ensuring regular watering, while in universities with limited resources these requirements may not always be available, which may reduce the actual benefits of shading and cooling compared to the basic design, and for this reason, our study treated vegetation as a procedure A complement (not a standalone procedure) that enhances the performance of more durable enclosed adjustments, such as glass enhancement and well-calculated canopy shading.
To express the elevation‑specific solar‑gain reductions in terms of indicative cooling‑load and CO₂ savings, the analysis applies a simple engineering conversion coefficient of 15%, representing the fraction of incident summer solar heat gain that typically appears as space‑cooling demand once thermal storage and convective–radiative splits are considered. This coefficient is treated as an assumption rather than a calibrated constant, and its influence is checked through a brief one‑way sensitivity analysis reported in Table 19.
Table 19. Sensitivity of indicative cooling-load savings to the conversion coefficient
|
Conversion Coefficient |
Total Summer Solar-Gain Reduction for Retrofit Package A (kWh) |
Indicative Cooling-Load Savings (kWh) |
Relative Change vs. 15% |
|
10% |
11,000 |
1,100 |
-33% |
|
15% (assumed) |
11,000 |
1,650 |
0% |
|
20% |
11,000 |
2,200 |
+33% |
Table 19 shows that varying the conversion coefficient between 10% and 20% linearly scales the absolute magnitude of cooling‑load savings but does not change the ordering or relative gaps between the retrofit scenarios. This confirms that the assumed value of 15% is adequate for comparative, design‑level decision‑making in this case study.
4.6 Winter shading and passive solar gains
Characteristic of Baghdad is a hot-arid steppe climate with a long anfd intense cooling season and a relatively short and mild winter. Climatological data show that normal daytime temperatures in Baghdad during winter range between 10 and 18 ℃, with daily high temperatures of about 16 ℃ and a daily low of about 4 ℃ in January. The number of cooling degree days is significantly higher than the number of heating degree days in the annual average [37-39].
Space conditioning in the case-study Deanship Building is thus controlled by the cooling system of summer with split-unit air-conditioners and only a few electric heaters during cold seasons. In these circumstances, the loss of passive winter solar gain due to more profound overhangs and low-SHGC glazing is anticipated to be relatively insignificant in comparison with the large-scale decrease of the cooling loads and the CO2 emissions that the proposed shading measures are likely to result in summer. Because of this reason, this analysis gives more importance to summer solar-gain reduction as the main design goal in the Baghdad setting but recognizes that the future implementation of the protocol in warmer climates should clearly re-weight winter performance.
5.1 Strategic recommendation
5.1.1 Phase I (Year 0–6 months): Application scenario 3 (Vegetation & Plants)
The lowest cost (1,850 USD) with immediate environmental impact and minimal disruption to day‑to‑day operations, while significantly improving air quality and biodiversity.
5.1.2 Phase II (Year 1–2): Adding scenario 1 (Canopies & Overhangs)
Incremental investment (3,700 USD) will be a cost-effective passive design: Additional cut-off of solar load of approximately 4-5 percent, and Annual Savings: Approximately adds 20 USD of energy savings, of pure energy savings, but drastically improves inside thermal convenience, and provides professional architectural identity of shading, will all be added after the Plants Stabilize (Gradual Improvement).
5.1.3 Phase III (Years 3-5): Scenario 2 (Glass) takes into consideration
High-performance investment of 6,600 USD will be implemented as part of routine maintenance, with the longest service life (25–30 years) as a long‑term asset that converts the building envelope into a modern energy‑efficient standard.
5.1.4 The combination of the strategies (all three scenarios)
Total Cars investment: 12,150 USD (phased over 3-5 years), will be projected to total 50-60% of base solar gain with Power consumption after optimization: ~380 kWh (out of 760 kWh /day) will be Projected Total Carbon emissions: 59 -reduction/ 12,150 USD = ~304 kg CO2 per year. Type of Investment: Although financial payback would be above 20 years since the amount of electricity payable in the area is low, the project can still be considered as a strategic environmental enhancement that would be required to ensure the sustainability of the campus.
5.2 Summary and limitations
The first and second stages (plants and canopies) are strongly suggested as a fast and much closer-to-the-point manner to act, but are efficient, sustainable, and can be initiated immediately. The latter case (glass) is long-term, as it is a part of the overall development plan of the building, which ensures the greatest efficiency and operational lifetime.
The financial assessment presented here is conservative because it considers only the solar gain component of cooling loads, without accounting for potential additional operational and comfort benefits. But the major factors are the environmental advantage and the comfort in temperatures.
This study has several limitations. The steady state model assumes constant occupancy and does not fully capture thermal lag effects in the building envelope (thermal inertia). The outcome of further studies should be to complement these results with in-place sensor measurements as a method of improving the cooling load coefficients.
Relying solely on energy cost savings to calculate the recovery period may make modernization projects seem financially unattractive (with temporary payback periods of more than 20 years), especially in countries with subsidized electricity prices, such as Iraq.
The relative arrangement of the three scenarios: plants provide the shortest semantic yield, glass provides the deepest reduction, and horizontal canopies in the middle, remained the same even though the sensitivity of the brief using alternative conversion coefficients of 10% and 20%, although the absolute values for reducing cooling load and yield are proportional to the chosen factor.
The current analysis does not explicitly show dynamic effects such as hourly temperature fluctuations or overlay of intermittent clouds, or changes in occupancy patterns, as these factors can change the exact timing and peak cooling loads, but they do affect the prevailing differences in solar gain captured by the model, and are therefore unlikely to change the relative order of the refresh options. Incorporating a fully time-based simulation and detailed occupancy schedules would be a useful extension in future work, especially for universities looking for accurate hourly upload files as well as design-level comparisons presented here.
Our study indicated that a radical shift towards a "budget-supported asset development" approach, with a typical annual maintenance budget below US\$15,000 for the Emad building, is thus the integrated renovation package proposed in this article (estimated to cost US\$12,150 exactly) within one fiscal year. Thus, the idea should be seen as an investment in upgrading the Deanship's infrastructure rather than as it will save on energy and water bills in the future. In this sense, the main return on investment is not short‑term cash flow, but longer‑term strategic performance of the retrofit to the building and the university.
Asset Modernization: This would extend the lifespan of the building through the installation of high-performance glazing and shading technologies.
Operational Resilience: Securing the already present HVAC equipment through minimization of peak cooling loads by around 50-60, hence alleviating pressure on the current HVAC equipment.
Institutional Reputation: The conversion of an average facility into a Green Campus paradigm.
Thus, the implementation is economically feasible, not because it pays for itself, that is, it reduces any bills, but it is used more effectively than traditional cosmetic repair in terms of using existing maintenance funds.
While the retrofit protocol and Excel model have been developed and applied mainly to cooling load conditions, envelope measures such as those examined in this study also impact winter load. Typically, larger overhangs and lower‑SHGC windows will slightly decrease the passive solar gains during winter, which may slightly increase the winter heating loads in climates with high winter loads.
However, in the hot‑arid climate of Baghdad, empirical data and feedback from building managers suggest that cooling is clearly the most dominant factor in the annual energy balance and occupant comfort, so the overall benefits of focusing on reducing solar gains in summer are still highly desirable. The protocol can be applied in other locations by explicitly including winter in the simulations, by incorporating seasonal calculations of heat loss, and by weighting the summer and winter performance according to climatic needs.
The study demonstrates that uncomplicated digital modeling tools (such as Excel), combined with freely available NASA climate data, can support high-impact design decisions in resource-limited settings, which paves the way to the extrapolation of the curriculum to other universities and universities in other Third World cities.
Natural shading and advanced window design can significantly contribute to reducing the demand for cooling energy in university buildings in hot areas such as Baghdad, as these strategies provide practical pathways for universities seeking to reduce their carbon footprint while improving thermal comfort.
The solar gain model demonstrated that a comparatively simple modification of the glass and the frames resulted in a great decrease in the cooling load and the carbon emissions, which proved that the individual efforts to improve the outer shell could result in the overturning effect of the activities of the expensive air conditioning systems.
A mixing of vegetative shading with the engineering solutions of awnings and highly efficient glass led to the presence of a multiplier cumulative effect, and the elevation becomes a climate-active elevation, not something that is not climbing in any way, but something that receives radiation.
It was determined that the structure and positioning of spaces (halls, offices, corridors) can be operated as a "thermal budgeting" scheme, and the most actively lit Elevations of the building should be used in less sensitive spaces, and it is possible to reduce the loads at no extra technological expense.
The work demonstrates the importance of bettering solar gain not only in terms of saving energy but also in interconnection with the quality of educational and mental health environments of students through better natural lighting, less glare, and excessive heating on high-peak hours.
This study demonstrates a very visible shortcoming in the literature regarding university building in the area where the concept of solar gain is significantly under-researched as a design feature that is adjustable and enchantable, but rather an imposition of climatic information, thereby offering a viable conceptual framework that can be referred to and modified when conducting further research.
This research provides a strong, accessible framework of a resource-constrained environment, but one realization that alludes to a serious future follow-up is to confirm these steady-state research results with dynamic simulation environments (like Design Builder or Energy Plus). This comparative analysis will be used in future research to further tune the suggested protocol, which is in relation to the transient thermal inertia and multi-component occupancy profiles.
Based on these lessons, a practical plan can be developed for other universities in hot‑arid climates in three stages. First, low‑cost green Elevations should be introduced on the most critical elevations of administrative buildings as a first‑win quick fix that does not require high investment. Second, medium‑cost horizontal canopies can be deployed to target the worst‑performing elevations identified with the Excel protocol, as per the simple solar‑gain checks outlined in this case study. Third, if long‑term resources are available, high‑cost glazing can be phased in, starting with auditoriums and high‑load offices. This sequence and reusage of the suggested Excel protocol with local weather data allow other universities and government offices to replicate the Deanship case study for their own building stock and budget planning.
Request universities to turn their existing buildings into so-called living study cases, where the solar gain and the efficiency of the suggested solutions (canopies, better glass, and plants) could be measured, and the results could be published in the transparent scientific forums to establish a knowledge network regionally.
From modeling on the solar gain, the adoption of a compulsory feasibility framework known as the Solar Assessment Protocol in the design and renovations of university buildings in the subtropical region that has hot, dry, and humid climatic systems begins at the level of an individual space before the adoption of final plans.
Introduce low-cost progressive initiatives that embrace vegetation cover (shade trees, climbing vegetation, elevation gardens) as the initial stage of acquiring solar radiation, which is connected to the urban sustainability initiatives and national vegetable afforestation plans.
Updating university building guides and standards in the countries of the region to include minimum SHGC limits, WWR ratios, and minimum shading factors for the south and west Elevations, while granting incentives to projects that achieve documented reductions in cooling loads.
Integrating the concept of solar gain and climate response into architecture and engineering curricula in the region, with real design projects for existing university buildings, these models become both an educational and research reference.
Introduce incentives policy packages (microfinance, competitive grants, partnership with the private sector) to initially apply shading and window optimization solution to university campuses and afterward to schools and publicly operated hospitals with similar weather conditions.
Development of an open regional database of building Elevations of exterior enclosures, types of glass, patterns of shading, and energy usage.
The authors would like to thank Al-Mustansiriyah University (www.uomustansiriyah.edu.iq), Baghdad, Iraq, for its support in the current work. And also, thanks to the University of Technology (www.uotechnology.edu.iq), Baghdad, Iraq.
Appendix A1 – Climate Data
Table A1, extracted from the NASA POWER database, presents the monthly solar radiation values (kWh/m²·day) for each of the four elevations' orientations (N, E, S, and W), along with average temperature and humidity data for Baghdad during the peak summer months (June–September).
Table A1. Climate data
|
Month (Gregorian) |
S Direction (kWh/m²∙day) |
E Direction (kWh/m²∙day) |
W Direction (kWh/m²∙day) |
N Direction (kWh/m²∙day) |
Avg Temp (℃) |
Humidity (%) |
Notes |
|
June |
7.3 |
5.8 |
6 |
4.9 |
44 |
25 |
Peak summer, lowest humidity |
|
July |
7.5 |
6.2 |
6.1 |
5.1 |
46 |
22 |
Hottest month of year |
|
August |
7.2 |
6 |
5.9 |
5 |
45 |
24 |
High heat load continues |
|
September |
6.5 |
5.3 |
5.2 |
4.5 |
40 |
30 |
Transition to autumn |
Appendix A2 – Glass properties
Table A2 summarizes the thermal and optical properties of the existing 6 mm clear single-pane glazing with iron frames used in the Deanship Building, including SHGC, U-value, and visible light transmittance.
Table A2. Glass properties
|
Property |
6mm Clear Glass (Iron Frame) |
Unit |
Notes |
|
Thickness |
6 |
mm |
Single pane, clear |
|
Solar Heat Gain Coefficient (SHGC) |
0.86 |
dimensionless |
High transmission for 6mm clear glass |
|
Visible Light Transmission (VLT) |
0.88 |
dimensionless |
Good natural daylight penetration |
|
U-Value (Thermal Conductance) |
5.89 |
W/m² |
Moderate insulation (metal frame conducts heat) |
|
Frame Material |
Steel/Iron |
material |
Uncoated, standard construction |
|
Frame Thermal Bridge Factor |
1.18 |
multiplier |
Metal frames increase heat transmission by 18% |
|
Effective SHGC (with frame thermal loss) |
0.86 |
adjusted |
SHGC unchanged, but frame adds conduction loss |
|
Annual Energy Efficiency Rating |
D-E |
rating |
Typical for standard iron-frame windows |
Appendix A3 - Solar Gain Baseline for floors
Tables 3, 4, and 5 display the calculated monthly and total summer solar heat gain (kWh) for each space on the ground,1st, and 2nd floors, based on glazing area, SHGC, shading factor, and incident solar radiation from NASA POWER.
Table A3. Solar gain baseline for ground floor
|
Space # |
Space Name |
Aglass (m²) |
SHGC |
Fshade |
June Q (kWh) |
July Q (kWh) |
August Q (kWh) |
Sept Q (kWh) |
Summer Total (kWh) |
Avg Monthly (kWh) |
|
1 |
Main Entrance |
14.4 |
0.86 |
0.65 |
235.2 |
247.3 |
230.4 |
185.1 |
898 |
224.5 |
|
2 |
Reception Hall |
15 |
0.86 |
0.6 |
221.4 |
233.1 |
216.9 |
174.6 |
846 |
211.5 |
|
3 |
Main Corridor |
17.28 |
0.86 |
0.58 |
153.7 |
168.4 |
161.4 |
131.9 |
615.4 |
153.9 |
|
4 |
Secretary Office |
4.4 |
0.86 |
0.5 |
51.6 |
54.3 |
50.6 |
40.8 |
197.3 |
49.3 |
|
5 |
General Storage |
1.6 |
0.86 |
0.75 |
14.4 |
14.8 |
14.3 |
12.2 |
55.7 |
13.9 |
|
6 |
Kitchen |
4.8 |
0.86 |
0.7 |
24.1 |
26.4 |
25.4 |
21.4 |
97.3 |
24.3 |
|
7 |
Public Restrooms |
3.24 |
0.86 |
0.65 |
24.2 |
26.5 |
25.4 |
20.8 |
96.9 |
24.2 |
|
8 |
Archive Room |
1.6 |
0.86 |
0.8 |
8.9 |
9.7 |
9.3 |
7.9 |
35.8 |
9 |
|
9 |
Room 101 |
7.2 |
0.86 |
0.45 |
68.5 |
72.1 |
67.2 |
54.1 |
262 |
65.5 |
|
10 |
Assistant Office |
5.28 |
0.86 |
0.5 |
61.8 |
65 |
60.5 |
48.7 |
236 |
59 |
|
11 |
Secondary Corridor |
8.8 |
0.86 |
0.65 |
78.8 |
81 |
78 |
66.6 |
304.4 |
76.1 |
|
12 |
Waiting Area |
6.9 |
0.86 |
0.55 |
42.4 |
46.4 |
44.5 |
36.4 |
169.7 |
42.4 |
|
13 |
Security Office |
4 |
0.86 |
0.55 |
41.8 |
44 |
41 |
33 |
159.8 |
40 |
|
14 |
Interior Garden |
17.6 |
0.86 |
0.75 |
88.4 |
96.6 |
93.1 |
78.6 |
356.7 |
89.2 |
|
15 |
Service Corridor |
3.2 |
0.86 |
0.7 |
26.6 |
27.3 |
26.3 |
22.4 |
102.6 |
25.7 |
|
FLOOR 0 TOTAL |
Ground Total |
130.98 |
0.86 |
0.63 |
1261 |
1335 |
1245.9 |
1004.5 |
4846.2 |
1211.6 |
Table A4. Solar gain baseline for first floor
|
Space # |
Space Name |
Aglass (m²) |
SHGC |
Fshade |
June Q (kWh) |
July Q (kWh) |
August Q (kWh) |
Sept Q (kWh) |
Summer Total (kWh) |
Avg Monthly (kWh) |
|
16 |
Dean's Office |
12.96 |
0.86 |
0.4 |
133.4 |
140.5 |
130.9 |
105.4 |
510.2 |
127.6 |
|
17 |
Dean's Secretary |
5.28 |
0.86 |
0.45 |
50.4 |
53 |
49.4 |
39.8 |
192.6 |
48.1 |
|
18 |
Scientific Deputy Office |
7.2 |
0.86 |
0.42 |
68.9 |
72.6 |
67.6 |
54.4 |
263.5 |
65.9 |
|
19 |
Scientific Deputy Secretary |
4.4 |
0.86 |
0.48 |
38.7 |
40.7 |
37.9 |
30.5 |
147.8 |
37 |
|
20 |
Admin Deputy Office |
7.2 |
0.86 |
0.5 |
50.9 |
55.7 |
53.5 |
43.7 |
203.8 |
51 |
|
21 |
Admin Deputy Secretary |
4.4 |
0.86 |
0.55 |
34 |
37.2 |
35.7 |
29.2 |
136.1 |
34 |
|
22 |
Lecture Hall 1 |
21.12 |
0.86 |
0.35 |
175.1 |
184.3 |
171.7 |
138.2 |
669.3 |
167.3 |
|
23 |
Lecture Hall 2 |
19.2 |
0.86 |
0.38 |
167.4 |
176.2 |
164.1 |
132.1 |
639.8 |
160 |
|
24 |
Main Conference |
16.56 |
0.86 |
0.4 |
170.1 |
179.1 |
166.9 |
134.3 |
650.4 |
162.6 |
|
25 |
1st Floor Corridor |
28.8 |
0.86 |
0.52 |
184.6 |
201.9 |
193.8 |
158.5 |
738.8 |
184.7 |
|
26 |
School 1 Office |
5.28 |
0.86 |
0.6 |
41.2 |
42.3 |
40.8 |
34.8 |
159.1 |
39.8 |
|
27 |
Room 108 |
6.9 |
0.86 |
0.55 |
49.6 |
50.9 |
49 |
41.8 |
191.3 |
47.8 |
|
28 |
School 2 Office |
5.28 |
0.86 |
0.68 |
26.4 |
28.9 |
27.8 |
23.5 |
106.6 |
26.7 |
|
29 |
Room 109 |
6.9 |
0.86 |
0.7 |
34.7 |
37.9 |
36.5 |
30.8 |
139.9 |
35 |
|
30 |
Educational Media Store |
1.6 |
0.86 |
0.75 |
8 |
8.7 |
8.4 |
7.1 |
32.2 |
8.1 |
|
31 |
Computer Room |
8.58 |
0.86 |
0.5 |
60.7 |
66.4 |
63.8 |
52.2 |
243.1 |
60.8 |
|
32 |
1st Floor Assistant Office |
4.84 |
0.86 |
0.58 |
33.1 |
34 |
32.8 |
28 |
127.9 |
32 |
|
33 |
1st Floor Secondary Corridor |
6.6 |
0.86 |
0.48 |
56.2 |
59.2 |
55.1 |
44.4 |
215 |
53.7 |
|
34 |
Room 104 |
6.44 |
0.86 |
0.5 |
45.6 |
49.9 |
47.9 |
39.2 |
182.6 |
45.7 |
|
35 |
Laboratory |
7.36 |
0.86 |
0.55 |
52.8 |
54.2 |
52.2 |
44.6 |
203.8 |
51 |
|
36 |
Committee Secretary Office |
2.1 |
0.86 |
0.52 |
13.4 |
14.6 |
14 |
11.5 |
53.5 |
13.4 |
|
37 |
Copy Room |
1.08 |
0.86 |
0.78 |
5.4 |
5.9 |
5.7 |
4.8 |
21.8 |
5.5 |
|
38 |
1st Floor Restrooms |
2.66 |
0.86 |
0.72 |
16.4 |
16.8 |
16.2 |
13.8 |
63.2 |
15.8 |
|
FLOOR 1 TOTAL |
1st Total |
173.64 |
0.86 |
0.52 |
1328.6 |
1405 |
1310.1 |
1054.9 |
5098.9 |
1274.7 |
Table A5. Solar gain baseline for the second floor
|
Space # |
Space Name |
Aglass (m²) |
SHGC |
Fshade |
June Q (kWh) |
July Q (kWh) |
August Q (kWh) |
Sept Q (kWh) |
Summer Total (kWh) |
Avg Monthly (kWh) |
|
39 |
Dean's Office 2nd |
12.96 |
0.86 |
0.4 |
133.4 |
140.5 |
130.9 |
105.4 |
510.2 |
127.6 |
|
40 |
Dean's Secretary 2nd |
5.28 |
0.86 |
0.45 |
50.4 |
53 |
49.4 |
39.8 |
192.6 |
48.1 |
|
41 |
Lecture Hall 3 |
21.12 |
0.86 |
0.35 |
175.1 |
184.3 |
171.7 |
138.2 |
669.3 |
167.3 |
|
42 |
Lecture Hall 4 |
19.2 |
0.86 |
0.38 |
167.4 |
176.2 |
164.1 |
132.1 |
639.8 |
160 |
|
43 |
Conference Room |
14.4 |
0.86 |
0.4 |
148 |
155.8 |
145.2 |
116.9 |
565.9 |
141.5 |
|
44 |
2nd Floor Corridor |
28.8 |
0.86 |
0.52 |
184.6 |
201.9 |
193.8 |
158.5 |
738.8 |
184.7 |
|
45 |
School 3 Office |
5.28 |
0.86 |
0.55 |
40.9 |
44.7 |
42.9 |
35.1 |
163.6 |
40.9 |
|
46 |
Room 204 |
6.9 |
0.86 |
0.5 |
48.9 |
53.5 |
51.4 |
42 |
195.8 |
49 |
|
47 |
School 4 Office |
5.28 |
0.86 |
0.62 |
36.3 |
37.3 |
35.9 |
30.7 |
140.2 |
35 |
|
48 |
Room 205 |
6.9 |
0.86 |
0.57 |
44.8 |
46.1 |
44.4 |
37.9 |
173.2 |
43.3 |
|
49 |
School 5 Office |
5.28 |
0.86 |
0.72 |
26.5 |
29 |
27.9 |
23.6 |
107 |
26.7 |
|
50 |
Room 206 |
6.9 |
0.86 |
0.75 |
34.7 |
37.9 |
36.5 |
30.8 |
139.9 |
35 |
|
51 |
Room 207 |
6.9 |
0.86 |
0.72 |
34.7 |
37.9 |
36.5 |
30.8 |
139.9 |
35 |
|
52 |
2nd Floor Secondary Corridor |
6.6 |
0.86 |
0.48 |
56.2 |
59.2 |
55.1 |
44.4 |
215 |
53.7 |
|
53 |
Committee Secretary 2nd |
2.1 |
0.86 |
0.52 |
13.4 |
14.6 |
14 |
11.5 |
53.5 |
13.4 |
|
54 |
Room 208 |
6.44 |
0.86 |
0.58 |
41.8 |
43 |
41.4 |
35.3 |
161.5 |
40.4 |
|
55 |
2nd Floor Restrooms |
2.66 |
0.86 |
0.78 |
13.4 |
14.6 |
14 |
11.9 |
53.9 |
13.5 |
|
56 |
Archives Store |
1.6 |
0.86 |
0.8 |
8 |
8.7 |
8.4 |
7.1 |
32.2 |
8.1 |
|
57 |
2nd Floor Assistant Office |
4.84 |
0.86 |
0.55 |
37.3 |
40.8 |
39.2 |
32 |
149.3 |
37.3 |
|
58 |
Equipment Room |
1.6 |
0.86 |
0.65 |
10.4 |
10.7 |
10.3 |
8.8 |
40.2 |
10 |
|
59 |
Department Library |
6.44 |
0.86 |
0.72 |
32.4 |
35.4 |
34.1 |
28.8 |
130.7 |
32.7 |
|
60 |
Waiting Hall 2nd |
6.9 |
0.86 |
0.55 |
53.3 |
58.3 |
56 |
45.8 |
213.4 |
53.4 |
|
61 |
Safety Corridor |
4.2 |
0.86 |
0.5 |
39.1 |
41.2 |
38.4 |
30.9 |
149.6 |
37.4 |
|
FLOOR 2 TOTAL |
2nd Total |
195.12 |
0.86 |
0.54 |
1369.3 |
1448.3 |
1349 |
1085 |
5251.6 |
1312.9 |
Source: Combine SPACE_INVENTORY A_glass glass area data with solar radiation data from NASA POWER, SHGC values, and F_shade shading coefficient, using the ASHRAE equation: $Q_{solar}=A_{glass} \times I_{incident} \times S H G C \times F_{shade} \times 30$ Per Month
Appendix A4—Energy Conversion Baseline
Table A6 presents the baseline energy conversion parameters used to translate the total summer solar gain into estimated cooling energy demand, CO₂ emissions, and operational cost, based on a COP of 3.0 and the Iraqi grid emission factor of 0.8 kg CO₂/kWh.
Table A6. Energy conversion baseline
|
Parameter |
Value |
Unit |
Formula/Calculation Basis |
|
Total Summer Solar Gain (4 months) |
15196.7 |
kWh |
Sum of June-September for all 499.74 m² glazing |
|
Average Monthly Solar Gain |
3799.2 |
kWh |
15196.7 / 4 |
|
Daily Average Summer Solar Gain |
126.6 |
kWh/day |
15196.7 / (4 × 30) |
|
Solar-to-Solar Gain from Fenestration Conversion Factor |
0.15 |
% |
ASHRAE standard: 15% of solar gain becomes AC load |
|
Estimated Cooling Energy Required (4 months) |
760~ |
kWh |
15196.7 × 0.15 / 3.0 |
|
COP (Cooling Equipment Efficiency) |
3 |
dimensionless |
Typical split A/C unit efficiency |
|
Average Monthly Solar Gain from Fenestration |
569.9 |
kWh |
760/4 |
|
|
|
|
|
|
Iraq Grid CO2 Emission Factor (2025) |
0.8 |
kg CO₂/kWh |
35% fossil, 55% gas, 10% renewable |
|
Annual CO2 from Summer Cooling |
608 |
kg |
760 × 0.8 |
|
Equivalent CO2 (metric tons) |
0.61 |
tonnes |
608 / 1000 |
|
Cooling Cost (at 0.12 USD/kWh) |
91.2 |
USD |
760 × 0.12 |
|
Equivalent Car Emissions (1 year) |
0.14 |
cars |
608 / 4400 kg per car per year |
|
Equivalent Tree Sequestration |
11 |
trees |
608 / 55 kg per tree per year |
|
Payback Potential (with intervention) |
Varies |
years |
See the scenario comparison |
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