scholarly journals Evaluation of Basement's Thermal Performance Against Thermal Comfort Model at Hot-arid Climates, Case Study (Egypt)

Author(s):  
Heba Hassan Kamel ◽  
Daisuke Sumiyoshi

Reaching thermal comfort levels in hot-arid climates is becoming more difficult nowadays without the use of high energy consuming mechanical systems. Therefore, the need to use effective passive energy design techniques such as earth-sheltered buildings is becoming greater. This paper combines researches that uses monitoring and simulations in order to evaluate basements’ thermal performance that reached thermal comfort levels without active air-conditioning systems, despite the harsh climate conditions. The case study was conducted in Al-Minya city, Egypt, which is known for its high diurnal range. The study calibrated a non-conditioned basement simulation model versus the monitored data to simulate its thermal performance. The greatest challenge was to calculate the ground temperature. To do this successfully, we used an iterative approach between packages of the basement preprocessor and Energy Plus / Design Builder until reaching a convergence. The iterative method results showed significant agreement between the measured and modeled data; with a correlation of 98 percent and errors with mean bias error and normalized root mean square error of -1.0 and 7.6 percent; respectively. On the other hand, the Energy Plus method, integrating the Xing approach, showed significantly divergent results between the simulated models versus the measured data. The calibrated model analysis evaluation, using the Fanger’s thermal comfort model, showed satisfactory results within the thermal comfort sensation range. The research results significance indicates that the precise customized detailed iterative method is essential to create the needed inputs which subsequently lead to near-to-actual outputs compared with other ground-contact simulation methods. In fact, the precise customized detailed iterative method approach may be used as a benchmark for simulators for easy and precise ground temperatures’ calculations and earth-sheltered buildings’ simulations.

Author(s):  
Heba Hassan Kamel ◽  
Daisuke Sumiyoshi

Reaching thermal comfort levels in hot-arid climates is becoming more difficult nowadays without the use of high energy consuming mechanical systems. Therefore, the need to use effective passive energy design techniques, such as earth-sheltered buildings, is becoming greater.This paper describes research, that uses monitoring and simulations, to evaluate basements’ thermal performance, which reached thermal comfort levels without active air-conditioning systems, despite the harsh climate conditions. The case study was conducted in Al Minya city, Egypt, which is known for its high diurnal range. The study calibrated a non-conditioned basement simulation model versus the monitored data to simulate its thermal performance. The greatest challenge was to calculate the ground temperature. To do this successfully, we used an iterative approach between packages of the Basement preprocessor and EnergyPlus/Designbuilder until reaching a convergence.The iterative method results showed significant agreement, between the measured and modeled data, with a correlation of 98 percent, and errors with mean bias error and normalized root mean square error of -1.0 and 7.6 percent, respectively. On the other hand, the EnergyPlus method, integrating the Xing approach, showed significantly divergent results between the simulated models versus the measured data. The calibrated model analysis evaluation, using the Fanger’s thermal comfort model, showed satisfactory results within the thermal comfort sensation range.The research results significance indicates that the precise customized detailed iterative method is essential to create the needed inputs which subsequently lead to near-to-actual outputs compared with other ground-contact simulation methods. In fact, the precise customized detailed iterative method approach may be used as a benchmark for simulators for easy and precise ground temperatures’ calculations and earth-sheltered buildings’ simulations.


2016 ◽  
Vol 835 ◽  
pp. 416-422
Author(s):  
Fahanim Abdul Rashid ◽  
Asrul Mahjuddin Ressang Aminuddin ◽  
Norafida Ab. Ghaffar

Over the past decade many studies were conducted to investigate the thermal performance of terraced houses in Malaysia. It was found that this housing typology failed to address the need for thermal comfort and alternatives to the narrow frontage with deep plan have been proposed with simulated good thermal performance. Although this is good progress for new generation of terraced houses, millions of units of terraced houses are still in use and new units with the outdated existing plans continued to get built due to consistently very high demand due to progressive urbanisation and rapid economic developments. Therefore, it is imperative that the thermal comfort issue for existing terraced houses is dealt with and through this paper a comparison between single and double storey terraced houses is made through analysis of indoor environmental monitoring (ambient temperature, relative humidity and air velocity) of two (2) selected case studies in Merlimau, Melaka. Contrary to popular belief, it is found that there is no statistical difference between both sets of indoor temperature and relative humidity between the case studies. This finding is indicative of the consistent and stable temporal temperature highs and lows in a 24 hour cycle despite the difference in indoor volume and distance between the ground floor and the roof cavity. Much of the reason is due to the materiality of the terraced houses construction and unsealed and uninsulated building envelope. Therefore, further research into improving the thermal performance of existing terraced houses of any typology have to be conducted to allow thermal comfort and to reduce reliance on high energy consuming air-conditioning.


Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5388
Author(s):  
Hao Sun ◽  
Carlos Jimenez-Bescos ◽  
Murtaza Mohammadi ◽  
Fangliang Zhong ◽  
John Kaiser Calautit

Natural ventilation is an energy-efficient way to provide fresh air and enhance indoor comfort levels. The wind-driven natural ventilation in courtyards has been investigated by many researchers, particularly the influence of the spatial configuration and environmental parameters on the ventilation and thermal comfort performance. However, previous research has mainly focused on the courtyard region instead of the indoor spaces surrounding it. Additionally, as a microclimate regulator, courtyards are rarely assessed in terms of the impact of vegetation, including its impact on energy consumption and thermal comfort. Evapotranspiration from vegetation can help lower air temperature in the surrounding environment and, therefore, its influence on the ventilation and thermal comfort in buildings with courtyards should be evaluated. The present study investigates the impact of vegetation on the aero-thermal comfort conditions in a courtyard and surrounding buildings in hot climates. Computational fluid dynamics was employed to evaluate the aero-thermal comfort conditions of the courtyard and surrounding buildings with different configurations of vegetation. The modeling was validated using previous works’ experimental data, and good agreement was observed. Thermal comfort indices were used to assess thermal performance. The study also evaluated the cover, height and planting area of vegetation in the courtyard. The results of this study can help develop tools that can assist the addition of vegetation in courtyards to maximize their effects. Future works will focus on looking at the influence of the strategies on different designs and layouts of courtyards.


2016 ◽  
Vol 851 ◽  
pp. 791-797
Author(s):  
Fahanim Abdul Rashid ◽  
Norafida Ab Ghaffar ◽  
Asrul Mahjuddin Ressang Aminuddin ◽  
Muhammad Azzam Ismail

A field study of residents’ thermal comfort in a naturally ventilated intermediate single storey terrace house was carried out at Merlimau, Melaka. An intermediate single storey terrace house was chosen as a case study and indoor thermal condition measurements were recorded for three days. The indoor ambient temperature, relative humidity and air speed were measured using on-site monitoring equipment to evaluate the thermal performance of this house. A questionnaire survey was also conducted involving all occupants to determine their thermal comfort perception of the same case study house. The aim of this study is to analyse the indoor thermal condition of an intermediate single storey terrace house in order to propose architectural features to climatically adapt to the local climate. In naturally ventilated condition, results showed that this house is thermally uncomfortable and the indoor thermal condition was between 2.7°C to 5.9°C higher than suggested temperatures stipulated in ASHRAE Standard 55. Consistently, five out of eight occupants or less than 80% of occupants voted the house as thermally acceptable according to ASHRAE Standard 55.


2021 ◽  
Vol 13 (12) ◽  
pp. 6706
Author(s):  
Faezeh Bagheri Moghaddam ◽  
Josep Maria Fort Mir ◽  
Isidro Navarro Delgado ◽  
Ernesto Redondo Dominguez

The aim of this paper is to investigate the thermal performance of vertical gardens by comparing the thermal comfort of bare (glazed) and green façades in the Mediterranean climate. The proposal consists of applying a vegetation layer on a glazed façade that could control solar radiation and reduce indoor air temperatures. This study investigates the thermal performance of green façades of an office building in the Mediterranean climate. For this purpose, the Gas Natural Fenosa Office Building as a case study was simulated, that is located on a site next to the coastline in Barcelona. Dynamic building energy simulation was used to determine and assess indoor thermal conditions and, for this reason, the IES VE as a simulation tool has been utilized. Thermal comfort was assessed through the adaptive comfort approach and results were analyzed and presented in the terms of indoor comfort conditions during occupied hours. As a result, the article shows that applying a green façade as a vegetation layer caused a reduction in the internal and external façade surface temperatures, as well as the indoor air temperature of the workplace. Additionally, enhancing indoor comfort in summer is closely associated with reducing the external surface temperature. In winter, it also protects the exterior surface from the low temperature of the outside, and all of this greatly increases thermal comfort performance.


2017 ◽  
Vol 27 (10) ◽  
pp. 1431-1444 ◽  
Author(s):  
Bin Cao ◽  
Maohui Luo ◽  
Min Li ◽  
Yingxin Zhu

In regions with hot climate, most office buildings tend to use mechanical cooling for indoor thermal comfort, which results in high energy consumption throughout the year. In this article, we highlight a case study in an office building in Shenzhen, which is located in the Hot Summer and Warm Winter Zone of China. The building's most distinctive feature is that it makes sufficient use of semi-outdoor spaces, which plays an important role to achieve occupants' comfort, meanwhile contribute to saving energy. Field studies were conducted on an open terrace and in an auditorium with openable walls. Air temperature on the open terrace varied between 28.8℃ and 30.6℃ during working hours on a summer day. Most occupants felt comfortable, although their averaged thermal sensation vote tended to be higher than neutral condition. In the auditorium when it was occupied on an autumn day, air temperature ranged from 26.1℃ to 27.4℃. The averaged thermal sensation vote values in the three sitting areas were −0.5, 0.3, −0.2 respectively, while no less than 70% of people felt thermally comfortable. In both spaces, the sensible airflow had positively impacted on occupants' comfort. The case study has proven the effectiveness of the strategy of using semi-outdoor spaces and could be a grounded example for new building designs in hot regions in China.


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