Provide Indoor Thermal Comfort Research Articles

Assessment of Indoor Thermal Condition on Traditional Vernacular Masjid: A Case Study on Masjid Kampung Laut, Malaysia

Traditional vernacular architectures in Malaysia include public buildings such as a masjid were designed with the tropical climate in mind and have proven to be an excellent example of providing indoor thermal comfort to the occupants. It is a naturally ventilated building being greatly influenced by the building designs. In traditional vernacular architecture, the roof is the main building enclosure that contributes to the total heat gain. Hence, the research aims to assess the indoor thermal condition of Masjid Kampung Laut, Kelantan, the first traditional vernacular masjid in Malaysia. Data were collected using the method of field measurement to evaluate the indoor comfort level of the masjid, in terms of indoor air temperature, air velocity, and relative humidity. The results demonstrate that the average indoor air temperature is acceptable and Masjid Kampung Laut responded favorably to the local climate. However, it is believed that with an increase of 0.4m/s to 1.2m/s of air movement, will further enhance indoor thermal comfort. Therefore, the findings can guide further thermal comfort prediction studies for other naturally ventilated buildings. Several other potential passive design strategies for roof design are proposed in this study to achieve acceptable indoor thermal comfort conditions for the masjid in Malaysia.

Analysis of Energy Efficient Features in Traditional Hill Architecture of Himachal Pradesh, India for its Indoor Performance in Sub-Tropical Climate

Vernacular architecture of any region highlights the architecture and construction methods developed by the locals, in need to provide indoor thermal comfort amidst outdoor climatic conditions which is done using the locally available materials and construction techniques in response to the climatic conditions and geographic location. At present in India, standardized building materials and construction methods are adopted for modern buildings due to the easy availability of materials and also serving well economically. This paper presents the results of a field study and simulations to investigate the thermal and energy performance of selected case study, two traditional houses using adobe blocks, rammed earth and stone construction are compared to a modern house using a masonry envelope, the construction material is altered by adding insulation to the building envelope to study the differences in the performance of original construction. The case study is located in Dharamshala town in the upper reaches of Kangra valley, Himachal Pradesh, India having a sub-tropical humid climatic condition. Hourly indoor temperatures of the houses were monitored and a field survey was done to collect the data, and simulations were carried using dynamic thermal simulation software DesignBuilder, the monitored data was then used to match the parameters in simulation models. The results show that indoor temperatures of traditional mud house provide better thermal comfort when compared to modern house, however, slightly high energy demand in traditional house is observed due to increase in discomfort hours.

Passive thermal regulation with 3D printed phase change material/cellulose nanofibrils composites

Application of phase change materials (PCM)-containing composite represents a promising passive thermal control strategy to provide indoor thermal comfort without using powered equipment. Yet, the trade-off between high thermal storage density and good thermal stability is the major obstacle that restricts the thermal regulation performance of the current PCM-containing products. This study proposed a facile approach to prepare PCM/cellulose nanofibrils (CNF) ink for 3D printed composite monolith, with very high PCM loading, good thermal stability, and robust mechanical properties. By incorporating a small amount of CNF gel as the stabilizer and viscosity modifier, the CNF-microencapsulated paraffin (model PCM) obtained essential printability to construct tailorable structure using Direct Ink Writing technology. After ice templating and freeze drying, the microencapsulated PCM particles were in-situ embedded in a CNF-assembled scaffold, forming a PCM/CNF composite. The lightweight nature of such scaffold (35.0 mg/cm3 for pure CNF matrix) endowed the composite monolith with high PCM loading (up to 82% with respect to the composite) and high thermal storage capacity (up to 153 J/g). Due to the 3D-interlinked CNF matrix and the coated CNF on PCM particles, the composite monolith not only exhibited high Young's modulus of up to 1.14 MPa but also showed exceptional thermal stability with negligible variation in microscopic morphology and thermal storage capacity, after high temperature conditioning at 80 °C for 30 h.

Preparation and performance in IR and UV of transparent inorganic polysiloxane coating with dispersed TiO2 on glass substrates

The aim of the presented work was to develop an economical, transparent coating with dispersed TiO2 dispersion and inorganic polysiloxane resin for glass windows application and to study its effectiveness in filtering IR and UV radiations. Two oligomeric silanes were prepared in different molar ratios to produce inorganic polysiloxane resin. They were tested for their viscosity to reflect the completion of the reaction and form an amide linkage. FTIR was done to support the viscosity result by proving the presence of amide linkages. 10%, 20%, and 30% of compounded TiO2 were successfully dispersed in 0.3% sodium sulfosalicylate (dehydrated ethanol). Each TiO2 concentration was characterized for size distribution and polydispersity index (PDI). Additives solutions of 2-hydroxybenzophenone (HBP) and boron trifluoride (BF3) were also soluted in the same solvent. Glass substrates were coated with the formulations and tested for curing and hardness properties. Windows Energy Profiler (WEP) was used to study the UV, IR, and daylight transmission of the coated glasses. Each inorganic polysiloxane resin showed various viscosity values before reaching a constant state which designates complete formations of amide linkages. Polysiloxane resin with a viscosity value of 30.5 mPa/s was the most ideal to act as a binder. FTIR characterization proved the formation of amide linkages. The particle size distribution of TiO2 recorded the size of 87 nm after dispersion with correlating value of 1 PDI. The fastest drying time of 3 hours was recorded. The pencil hardness test quoted 6H pencil as the hardest pencil grade. WEP analysis of UV, IR, and daylight transmission gives satisfactory results of 0%, 7%, and 61%, respectively. Laboratory analysis for viscosity tests often being held off. The test requires the samples to be transferred in a cylinder with an open-air spindle rotation. Samples react with the surrounding environment. Thus, polymerization takes place rapidly, resulting in hardened samples inside the cylinder. The different measure was taken by wrapping the testing area with aluminium foil. This research was conducted under equatorial climate. The obtained test results may contribute to the conclusion of transparent TiO2 nano-particles coating on glass substrates for windows application. This can reduce the electricity usage in buildings for artificial cooling to provide indoor thermal comfort. Smart coating formulations have a noticeable effect on filtering harmful solar radiation. This study presents the economical and undemanding ways to develop transparent smart coating formulation with superior performance against solar radiation. It is expected to have a bright potential in the architectural industry.

Performance evaluation of solar chimneys in providing the thermal comfort range of the building using phase change materials

Among passive systems, Solar Chimney (SC) is so beneficial in providing thermal comfort (Ventilation and heating), decreasing electricity cost (Economical) and pollution (Environmental). In addition, solar chimneys can reduce the risk of infection spreading by changing indoor air with fresh air. A numerical model of a house was simulated in three different modes in EnergyPlus: without SC, with SC, and with SC combined with a layer of phase change material (PCM). For these cases, terms of thermal comfort have been determined under three different climates: Hot-Arid (Yazd), Hot-Humid (Bandar Abbas), and Cold Semi-Arid (Tehran) climates. The results showed that combining PCM in solar chimneys causes dissatisfaction in Hot-Arid climate in both modes of SC operation (Ventilation and Heating). But in Hot-Humid and Cold Semi-Arid, PCM assists SC in providing indoor thermal comfort. The average thermal comfort indices (PMV) improve from “0.75″ to ”0.67″ (Summer-SC) and “-0.07″ to ”0.04″ (Winter-SC) for the Hot-Humid city. Also, PMV index changed from “1.24″ to ”1.16″ (Summer-SC) and “-1.1″ to ”-0.85″ (Winter-SC) in the Semi-Arid city after adopting PCM. Among all cases, PCM had the most positive effect in the cooling mode of Cold Semi-Arid climate (Tehran).

Experimental evaluation of an earth–to–air heat exchanger and air source heat pump hybrid indoor air conditioning system

Earth-to-air heat exchanger (EAHE) technology is promising for space heating/cooling. However, in most climates, EAHE alone cannot provide indoor thermal comfort. Hybrid systems combining an EAHE and an air-source heat pump (ASHP) can be used for indoor temperature regulation and energy conservation. We performed full-scale experiments to investigate the hybrid system performance for a building located in a typical hot-summer and cold-winter region of China. Variations in EAHE outlet/indoor air temperature, humidity, cooling/heating loads, energy consumption, and coefficient of performance (COP) were investigated. The results demonstrate a maximum reduction of 14.2 °C during summers and maximum gain of 8.2 °C during winters for the EAHE outlet air temperature, when the air-change rate per hour reaches 16.0. Moreover, the EAHE dehumidifies 1.95 g/kg moisture on average in summer, approximately accounting for 36.2 % of the dehumidification capacity of the hybrid system, with more dehumidification capability for high moisture contents. Compared with an independent ASHP for specific ambient air temperature and humidity ranges, the proposed system exhibits an average energy consumption reduction of 50.91 % and 16.78 %, increases COPASHP by 65.42 % and 11.21 %, and increases COPt by 145.37 % and 82.63 % during the summer and winter periods, respectively.

Experimental Study of Beeswax / Rice Husk Ash Phase Changes Material as Energy Storage in Concrete

Buildings with lightweight concrete are currently used as a solution for mass housing construction which is relatively cheaper, although it does not provide indoor thermal comfort due to the use of this building material. Lightweight concrete building materials are able to store heat for a long time, so that at night the heat is released indoors. The combination of building materials and PCM is an efficient way to increase the storage capacity of thermal energy in building components. The purpose of this study was to determine the compressive strength of the concrete if the coarse aggregate (gravel) was replaced by part of the gravel material using the Phase Change Material of beeswax (beeswax) according to the required percentage starting from 0%, 5%, 10%, 15% and if the aggregate was fine. (Sand) is partially replaced aby using Rice husk ash with various variations starting from 0%, 5%, 10%, 15%. In addition, this utilization is a good alternative, because there will be a process of utilizing rice husk ash which was previously wasted while these items can be used or processed into additives to the concrete mixture.

Experimental Study of Beeswax / Rice Husk Ash Phase Changes Material as Energy Storage in Concrete

Buildings with lightweight concrete are currently used as a solution for mass housing construction which is relatively cheaper, although it does not provide indoor thermal comfort due to the use of this building material. Lightweight concrete building materials are able to store heat for a long time, so that at night the heat is released indoors. The combination of building materials and PCM is an efficient way to increase the storage capacity of thermal energy in building components. The purpose of this study was to determine the compressive strength of the concrete if the coarse aggregate (gravel) was replaced by part of the gravel material using the Phase Change Material of beeswax (beeswax) according to the required percentage starting from 0%, 5%, 10%, 15% and if the aggregate was fine. (Sand) is partially replaced aby using Rice husk ash with various variations starting from 0%, 5%, 10%, 15%. In addition, this utilization is a good alternative, because there will be a process of utilizing rice husk ash which was previously wasted while these items can be used or processed into additives to the concrete mixture.

Sustainable Guidelines for Enhancing Indoor Thermal Comfort in Coptic Churches in Egypt Using Passive Design Strategies; Case Study St. Barbarah and Virgin Mary Churches

Since the 20th century, the temperature has risen, worldwide, due to climate change causing global warming. Such phenomena have resulted in thermal dissatisfaction within various buildings indoor spaces including Egyptian Coptic Orthodox churches. Heritage churches designs have always implemented passive strategies to provide indoor thermal comfort. However, modern churches design tend to use active strategies to provide indoor thermal satisfaction instead of referring to the use of passive designs. Accordingly, the main purpose of this research is to identify a set of guidelines to enhance indoor thermal comfort in modern Coptic Orthodox churches using passive design strategies. The research has adapted a mixed method approach where an in-depth literature review resulting a qualitative summary of passive techniques used in heritage Coptic churches, then followed by a comparative analysis between two Egyptian case studies; the first is a heritage church (St. Barbarah church) and the other is modern which is (Virgin Mary church) based on the deducted passive strategies from the literature. Moreover, an applicable simulation for varying the methodology, using Design Builder, where the modern church will be simulated and tested for thermal comfort before and after modifying it using the passive strategies deducted from the literature. The research’s main findings were the list of passive techniques that could be used to enhance the indoor thermal comfort, while the simulation experimental results where related to a typical summer week, showing that for the average air temperature and the average solar gains, the triple glazing was the most effective in causing indoor thermal comfort. But, for the average relative humidity and average of total fresh air, insulation has shown to be most effective in providing enhanced indoor thermal comfort. To conclude, a set of guidelines has been deduced from the methods adapted in the research showing the most suitable and applicable passive design strategies that could be used inside Coptic Orthodox churches to enhance indoor thermal comfort.

Minimizing heat transmission loads and improving energy efficiency of building envelopes in sub-Saharan Africa using bio-based composite materials

Increasing effect of climate change coupled with global warming has necessitated the need for mechanical cooling in buildings to provide indoor thermal comfort. Many countries in tropical climates, particularly in sub-Saharan Africa, use sandcrete blocks for constructing building envelopes which have relatively high thermal conductivity. This leads to increased heat transmission through the building walls resulting in increased building electricity consumption using air-conditioners. This study focused on opportunity of minimizing the thermal conductivity of sandcrete blocks by mixing it with available bio-based local materials, specifically treated sawdust and palm fibers. Experiments were conducted to determine the thermal conductivity, compressive strength and densities of sandcrete mixed with 10%, 20%, 30% and 40% of treated sawdust and palm fiber to form building block composites. The study results showed that incorporating the bio-based material into the sandcrete decreases its density and thermal conductivity, thereby decreasing the wall heat transmission load. Using a minimum standard limit of 3 MPa for compressive strength for building envelopes, the composite samples: S10, P10, P20 and P30 were found to be appropriate to be used to minimize wall heat transmission. The composite of 70% sandcrete with 30% treated palm fiber (P30) exhibited the best thermal performance with 38% reduction in thermal conductivity compared to the control sandcrete block. Maximum wall heat flux reduction of 52 W/m2 was attained at peak load with the composite P30 compared to the control sample P0 (100% sandcrete). In addition, using the degree-days cooling for Ghana, the analysis indicated maximum electricity saving potential of 453.40 kWh per year for an office space cooling using the sandcrete-palm fiber composite P30 as the building envelope.

A Review of Green Roof: Definition, History, Evolution and Functions

In cities, buildings contribute large unused panels, especially on their wall and roofs. These external surfaces generally made from materials that listed as a reflector to the heat such as concrete, glass, and bricks. Covering the external surfaces with green vegetation could be a solution to many environmental, economic and social problems, especially in the urban areas. A review was directed of studies that reported and measured on the relationship between characteristics of vegetation and their influence on building thermal performance, air and water pollution, and building energy-efficient. A numerous of published studies were investigated for their: (a) definition based on roof typologies and combinations; (b) historical evolution periods; (c) observation the green system functions. These analyses cover to afford scholars with a review of conventional techniques to understand one of the passive cooling strategies adopted in warm and cold climates. The techniques provide a significant contribution to the field of sustainable architecture, also to improve understanding of the progressive developments of a green roof. Despite other new designs of green system, this conventional and simple green roof has remained to contribute significantly to provide indoor thermal comfort.

Improving thermal environment for school buildings in Palestine, the role of passive design

School buildings have an enormous impact on students’ health, well-being and educational achievement; they also have an impact on energy consumption and other natural resources. Solar chimneys, solar walls, underground ducts for ventilation, shading, and building orientation were used to improve the indoor thermal environment in a pilot project school. A quantitative analysis was carried out based on field measurements by recording some thermal comfort parameters (mainly air temperature and relative humidity) for one year in the school. The aim was to evaluate the effects of the solar chimney, solar wall and underground duct used in selected classrooms on the indoor thermal environment and compare the results to base case classrooms in the same school. The study provided positive results confirming that the passive environment control system used in the pilot school is highly effective in providing indoor thermal comfort on hot and sunny days. The impact of ground ducts and solar chimneys on cold days was relatively small. Most of the classrooms tested on the three floors of the building were found to be thermally uncomfortable in winter.

Evaluation of vernacular and new housing indoor comfort conditions in cold climate – a field survey in eastern Turkey

PurposeThe purpose of this study is to compare vernacular and new houses in terms of indoor occupant satisfaction and thermal and visual comfort in a region with cold climatic conditions. In line with the data obtained, the contribution of passive design techniques to comfort in housing indoor will be revealed.Design/methodology/approachIn this study, the comfort conditions to be provided in a residence were determined and evaluated in Bingol with the help of questionnaires applied on vernacular and new houses. The information gathered from the occupants and the survey study was mainly designed for three purposes: (i) acquiring general information about houses; (ii) acquiring general information about occupants; and (iii) inquiring about the physical comfort satisfaction of the occupants (thermal comfort and visual comfort).FindingsAlthough the average occupant satisfaction in terms of thermal performance in vernacular houses in summer and winter is 3.91, this average is 2.01 for new houses. The average of the general visual comfort of occupants in vernacular houses is 3.59, whereas this rate is 2.63 in new houses. According to the data obtained, occupant satisfaction was higher in vernacular houses than in new houses. In general, the new settlement area is designed and positioned independently of climate and environmental conditions. This situation increases the need to use mechanical systems to provide indoor thermal comfort conditions. The increase in the need for mechanical systems leads to a significant increase in energy expenditures, as well as deterioration of health conditions in places.Research limitations/implicationsTo ensure occupant satisfaction, indoor thermal comfort conditions and healthy environments, vernacular houses should be an example for the design and building of new houses in terms of orientation, environment relations, space dimensions and space usage in accordance with the character of the region and material selection.Originality/valueThere has not been a serious research on bioclimatic, socioeconomic and cultural sustainability of the vernacular architecture of Bingol. Therefore, this region has been preferred as the study area.

Robust evaluation method of thermal deviation of air distribution

Air distribution (e.g., mixing ventilation) is widely used to provide indoor thermal comfort. The thermal deviation is defined as the deviation between the thermal condition and thermal preference, and a thermal deviation closer to zero indicates a more comfortable thermal environment. The thermal deviation is significantly affected by uncertainties in the thermal preference and cooling load. However, the conventional design method of air distribution evaluates the thermal deviation in a deterministic manner, which could result in an improper design with poor thermal comfort. This study innovatively proposes a robust thermal deviation evaluation method and uses it for the design optimization of air distribution. Monte Carlo simulations are employed to treat uncertainties in the thermal preference and cooling load. From the Monte Carlo simulations, the thermal deviation D0.95 is quantified with a confidence level of 0.95. The thermal deviation D0.95 should be minimized to optimize the design of air distribution robustly. Tests based on experiments of an energy efficient air distribution, i.e., stratum ventilation, have been conducted to validate the evaluation method proposed. Results show that the robust design based on the evaluation method proposed can ensure thermal comfort, while the conventional design risks thermal discomfort due to the uncertainties. Compared with the robustly optimized variable-air-volume system of stratum ventilation, the robustly optimized constant-air-volume system of stratum ventilation improves thermal comfort by 8.5% with the thermal deviation D0.95 reduced from 0.682 to 0.624. Therefore, the evaluation method proposed contributes to designing and comparing air distributions robustly for thermal comfort improvement.

Energy efficiency and cost saving opportunities in public and commercial buildings in developing countries – The case of air-conditioners in Ghana

Available data and market surveys conducted in Ghana have shown that 60–80% of electricity consumed in offices of public and commercial buildings is used to run air-conditioners to provide indoor thermal comfort for productive office work. Electricity consumptions of these air-conditioners are relatively high and are in the range of 3000–5400 kWh/yr per air-conditioner depending on the brand and the cooling capacity. Low energy efficiency rating of the air-conditioners is a major contributing factor to their high electricity consumption.This present work has conducted studies on the energy efficiency of air-conditioners used in the offices of public and commercial buildings in Ghana. Technical data from a national survey conducted on air-conditioning equipment used in the country was used for this study. In addition, a power quality clamp meter was used to monitor the actual power consumptions of stratified samples of the conventional air-conditioners in the offices, as well as that of an inverter air-conditioner installed in an office.The results from this study show that over 85% of air-conditioners used in Ghana exist in the lowest energy efficiency ratio category (1-star) and the remaining percentages are in the next lower categories (2 and 3-stars). It has been determined that enforcing energy efficiency regulations to shift the air-conditioner market in Ghana into the higher energy efficiency ratio (EER) categories has huge benefits for the country. For instance, there are annual electricity savings potential of 260 GWh and 1770 GWh respectively for the year 2020 and 2030 using inverter air-conditioners which have higher energy efficiency rating (4-star equivalent) compared to the current lower EER air-conditioners in the country. It is also determined that if Ghana continues to follow business as usual with low EER air-conditioners, it will need to install electricity generation capacity of about 480 MW by 2030 to handle influx of low energy efficient air-conditioners alone.Financial analysis has also revealed that there is opportunity for electricity consumption cost savings of about US$ 1.96 billion from the year 2018–2030 with higher EER air-conditioners (4-star) being installed in the country compared to the current low EER air-conditioners.

Preliminary evaluation of indoor thermal comfort in Malaysia heritage mosque

Malaysia heritage buildings are the country's architectural gems. Among them is the religious building such as mosque. The Malaysia heritage mosque is normally built in response to the local culture and environment. Unlike most of Malaysia modern mosques where air conditioning is opted as ventilation mode, the heritage mosques achieve indoor thermal comfort via the passive architectural design. Due to that, this study was executed with the purpose of investigating the indoor thermal comfort of a Malaysia heritage mosque located at traditional street in Melaka, namely Masjid Tanah. The methodology used in the study was field measurement, in which the parameters measured were the indoor and outdoor air temperatures. The field measurement was conducted for two days in the end of March and early of April 2018, from 9 am to 4 pm. The indoor predicted comfort temperature was derived using the adaptive model. The findings indicated that the measured indoor air temperatures were lower than the indoor predicted comfort temperatures at most of the time. Therefore, it shows that the passive architectural design adopted by the Malaysia heritage mosque, which is Masjid Tanah, is able to provide indoor thermal comfort to the users.

Indoor thermal environment due to non-steady-state radiation heat transfer of a capillary ceiling radiation cooling system

The capillary ceiling radiation cooling panel (C-CRCP) is a newly developed terminal device for air conditioning to provide indoor thermal comfort for occupants and to save energy. In this paper, numerical modelling of a room with a C-CRCP system was used to analyze radiant heat transfer under non-steady-state conditions. Experiments were conducted in an environmental chamber to verify simulation results. The chamber was equipped with a C-CRCP, which was covered with gypsumboard. The results showed that the inlet water temperature had a significant influence on ceiling surface temperature. The ceiling surface temperature and the steady-state time were increased with higher inlet water temperature. A vertical gradient in indoor air temperature was found. Ceiling surface temperature and indoor air temperature were increased with an increase in inlet air temperature. The energy supply rate of the radiant panel had a positive correlation with chilled water velocity. The amount of radiation was double the amount of convection, and the thickness of the gypsumboard had virtually no effect on the proportions of radiation and convection. The model was considered validated since the maximum relative errors between experimental data and simulation results of inlet water temperature and supply air conditions were within 10%.

Evaluation of Thermal Comfort in Traditional Houses in a Tropical Climate

A considerable amount of energy is being consumed for heating and cooling indoor environments in order to provide thermal comfort. For older buildings located in the southern parts of Iran, particularly in Bushehr, many climatic and passive design strategies are being used to provide indoor thermal comfort. This architecture and these elements have been developed in response to unfavorable weather conditions. The current study aimed to identify those passive elements and evaluate indoor thermal comfort in older houses. To achieve these objectives, passive elements in main houses located in the ancient urban structure were first identified. Then, a house in the coastal belt, Tabib’s house, and another house inside the ancient urban structure, Nozari’s house, were selected for the purpose of field measurement. The results revealed that the passive techniques used in these older houses significantly provide sufficient indoor thermal conditions. The mean measured predicted mean vote (PMV) of Tabib’s rooms was 0.88 and the mean measured PMV of Nozari’s rooms was 0.91, which were in an acceptable range. The measured predicted percentage of dissatisfied of rooms in both houses were lower than 10%. The main factor in creating indoor thermal comfort in these houses was the natural ventilation and its availability in the selected houses.

Influence of Iwans on the Thermal Comfort of Talar Rooms in the Traditional Houses: A Study in Shiraz, Iran

In traditional buildings many climatic strategies have been used to provide indoor thermal comfort in south and central parts of Iran. A common element is called an iwan. This study investigates the indoor thermal comfort of a room adjoined to a talar in a traditional house which has an iwan, in Shiraz, Iran. The data related to the temperature and relative humidity of the room are used to calculate the thermal comfort index of PMV (Predicted Mean Vote) and PPD (Predicted Percentage of Dissatisfied) by considering the following two cases: a talar room with an iwan and one without an iwan, by means of DesignBuilder software. For the purpose of validation, the air temperature and relative humidity of the talar room with an iwan were measured over 10 days and compared to the results of the simulation. Having a valid simulation, computation was conducted for the selected house in various cases for an annual passive operation of calculating PMV and PPD. The numerical results revealed that the talar room adjoined to an iwan located in the south front of the courtyard had relatively good conditions during the hot months, including June and July. In addition, it could provide fully satisfactory comfort conditions during August and September. According to the results, it is found that the iwan makes a talar room 62% more desirable for the hot months in comparison with a talar room without an iwan.

Parameterization of traditional domed-roofs insolation in hot-arid climates in Aswan, Egypt

This paper is part of a continuing study that aims at investigating the relationship between the amount of the solar radiation received on curved roofs and their geometrical configurations. It introduces computational method as a tool for the parametric approach in passive building design, enhancing the use and design of traditional domed-roof forms in hot-arid climates. The main objective behind this is to explore multiple configurations of domed-roof forms (semicircular, pointed, and faceted) and perform insolation investigations on them to discover the form that minimizes the quantity of received solar radiation with regard to variations in the received average daily solar irradiance (kW h/m2/day). The geographical latitude of Aswan (23.58°N) has been chosen to represent hot-arid regions of southern Egypt. Rhinoceros’s Grasshopper, a graphical algorithm editor, its component of gECO, and Autodesk’s Ecotect are utilized to establish such approach. The findings of the paper confirm that the maximum average daily solar irradiance is often recorded at flat surfaces. While the value varies from dome form to another, it decreases with the increase of the concaveness of domed-roof forms. The findings accomplish that domed-roof forms facilitate a significant decrease in the received average daily solar irradiance above their surface, when compared to flat surface, in both summer and winter. The paper concludes that domed-roof forms have great impact on minimizing the intensity of the received solar irradiance by maximizing the ratio between the dome’s height and its radius. Thus, they reduce the required energy for cooling in hot climates, and consequently, provide indoor thermal comfort.