scholarly journals Impact of the Design of Walls Made of Compressed Earth Blocks on the Thermal Comfort of Housing in Hot Climate

Buildings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 157 ◽  
Author(s):  
Césaire Hema ◽  
Adamah Messan ◽  
Abdou Lawane ◽  
Geoffrey Van Moeseke
Keyword(s):  
Thermal Comfort ◽  
Inside Surface ◽  
Living Room ◽  
Thermal Discomfort ◽  
Hot Climate ◽  
Compressed Earth Blocks ◽  
Concrete Blocks ◽  
Earth Blocks ◽  
Annual Reduction ◽  
The Impact

This study investigated the impact of the design of wall systems, mainly made of compressed earth blocks (CEB), on the indoor thermal comfort of naturally ventilated housing in hot climates of Burkina Faso. Conventional housing was modeled and calibrated using the WUFI® Plus dynamic simulation tool based on typical field surveys and the literature. This allowed testing the ability of different wall designs to impact thermal comfort. Thermal discomfort was assessed through an adaptive approach and was based on the annual weighted exceedance hours of overheating. Six designs of walls made of CEB and other locally available materials were simulated and compared to those made of classical hollow concrete blocks. The results of the simulation reveal that the profiles of thermal discomfort vary depending on the wall designs and building spaces. Thus, the wall made, from the outside toward the inside surface, of plywood of 2 cm, an insulation layer of 5 cm and a CEB layer of 29 cm thickness is the most suitable for an annual reduction in overheating for the living room. Regarding the bedroom, the most suitable wall is made of a 14 cm CEB layer, 5 cm insulating layer and 2 cm wood layer from the outside toward the inside surface.

scholarly journals Building and Urban Cooling Performance Indexes of Wetted and Green Roofs—A Case Study under Current and Future Climates

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6192
Author(s):  
Madi Kaboré ◽  
Emmanuel Bozonnet ◽  
Patrick Salagnac
Keyword(s):  
Thermal Comfort ◽  
Emission Scenario ◽  
Green Roof ◽  
Heat Fluxes ◽  
Temperate Climate ◽  
Passive Cooling ◽  
Thermal Discomfort ◽  
Indoor Thermal Comfort ◽  
Performance Indexes ◽  
The Impact

We developed and studied key performance indexes and representations of energy simulation heat fluxes to evaluate the performance of the evaporative cooling process as a passive cooling technique for a commercial building typology. These performance indexes, related to indoor thermal comfort, energy consumption and their interactions with their surrounding environments, contribute to understanding the interactions between the urban climate and building for passive cooling integration. We compare the performance indexes for current and future climates (2080), according to the highest emission scenario A2 of the Special Report on Emission Scenario (SRES). Specific building models were adapted with both green roof and wetted roof techniques. The results show that summer thermal discomfort will increase due to climate change and could become as problematic as winter thermal discomfort in a temperate climate. Thanks to evapotranspiration phenomena, the sensible heat contribution of the building to the urban heat island (UHI) is reduced for both current and future climates with a green roof. The performance of the vegetative roof is related to the water content of the substrate. For wetted roofs, the impacts on heat transferred to the surrounding environment are higher for a Mediterranean climate (Marseille), which is warmer and drier than the Paris climate studied (current and future climates). The impact on indoor thermal comfort depends on building insulation, as demonstrated by parametric studies, with higher effects for wetted roofs.

Optimal Minimum Airflow for Air Circulation of Single-Duct VAV Terminal Boxes

2008 ◽  
Author(s):  
Young-Hum Cho ◽  
Mingsheng Liu
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Thermal Discomfort ◽  
Variable Air Volume ◽  
Air Handling Unit ◽  
Optimal Value ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations ◽  
Air Circulation ◽  
The Impact

Thermal comfort in an area is directly controlled by terminal boxes in variable air volume (VAV) air-handling unit (AHU) systems. The terminal box either modulates airflow or adjusts the discharge air temperature. Reduced air circulation will cause thermal discomfort in a conditioned space if the airflow and discharge air temperature are not suitable. The objective of this study is to identify an optimal value for airflow and discharge air temperature that will maintain room thermal comfort. Optimal room airflow and discharge air temperature is analyzed, and the impact of room airflow and discharge air temperature on thermal stratification is verified through CFD (Computational Fluid Dynamics) simulations.

Summer thermal comfort and overheating in the elderly

2019 ◽  
Vol 40 (4) ◽  
pp. 426-445 ◽  
Author(s):  
Caroline Hughes ◽  
Sukumar Natarajan
Keyword(s):  
Thermal Comfort ◽  
Elevated Temperatures ◽  
Thermal Conditions ◽  
The Elderly ◽  
Vulnerable Groups ◽  
Climate Projections ◽  
Living Room ◽  
Warm Summer ◽  
Typical Summer ◽  
The Impact

Atypically warm summers such as 2003 and 2018 are predicted to become normal by 2050. If current climate projections are accurate, this could cause heat-related mortality to rise by 257% by 2050, the majority of which will be in vulnerable groups such as the elderly. However, little is known about the temperatures achieved in the homes of the elderly even in typical summers, and even less on whether these are comfortable. This study examines, for the first time, the validity of current thermal comfort models in predicting summer comfort levels in the 65+ demographic over a typical and an atypically warm summer. This was achieved through the first longitudinal study of thermal conditions in homes of the elderly in the South West UK, utilising repeated standardised monthly thermal comfort and health surveys with continuous temperature monitoring in both living and bed rooms. Results show that neither the PMV/PPD model (ISO 7730) nor the adaptive model (ISO 15251) accurately predict true thermal comfort in our sample. Overheating analysis using CIBSE TM59 (based on ISO 15251) suggests significantly more homes (50% living room, 94% bed room = 94% overall) overheated during the atypically warm summer, compared to the typical summer (3% living room, 57% bed room = 57% overall). These are worrying results, especially for the elderly, given the projected increases in both the severity and the frequency of extreme summers in a future, changed, climate. Practical application: This paper provides new data on the performance of the homes of the elderly in both a typical and atypically warm summer. Our results could be considered for building performance evaluation in homes with elderly occupants to mitigate overheating risk. Crucially, we not only examine the impact of CIBSE criteria on these homes but also look at thermal acceptance, which is important to understand the true impact of elevated temperatures in this demographic.

scholarly journals Improving Water Resistance of Compressed Earth Blocks Enhanced with Different Natural Fibres

2017 ◽  
Vol 11 (1) ◽  
pp. 433-440 ◽  
Author(s):  
Humphrey Danso
Keyword(s):  
Water Resistance ◽  
Natural Fibres ◽  
Palm Fruit ◽  
Sustainable Building ◽  
Rainfall Condition ◽  
Compressed Earth Blocks ◽  
Erosion Test ◽  
Earth Blocks ◽  
The Difference ◽  
The Impact

Background: Studies have shown a great potential for the use of Compressed Earth Blocks (CEBs) as a sustainable building material due to its economic, environmental and social benefits. Objective: This study investigates the water resistance characteristics of CEBs reinforced with different natural fibres. Methods: The fibres were sourced from coconut husk, sugarcane bagasse and oil palm fruit at 1 wt% added to two soil samples. The CEB specimen size of 290 × 140 × 100 mm was made at a constant pressure of 10 MPa and dried in the sun for 21 days. Accelerated erosion test was conducted to determine the resistance of the specimen to continuous rainfall condition. Results: It was discovered that the fibres helped in reducing the erodibility rate of the blocks, though there were some degrees of damage. The difference between the water resistance of the unreinforced and fibre reinforced CEBs were found to be statistically significant. Furthermore, the surface of the fibre reinforced blocks eroded rapidly in depth than the internal part, and there was reduction in the depth difference of the erosion with increase time of water spraying on the specimens. Conclusion: The study concludes that though the addition of fibres in soil blocks does not completely prevent the block from erosion, the impact of the fibres on the blocks significantly reduces the erosion.

scholarly journals The Impacts of Orientation and Building form on Internal Temperature of Visitor Center Building for Moderate and Hot Climate

2021 ◽  
Vol 9 (6) ◽  
pp. 106-110
Author(s):  
Alzaed Ali
Keyword(s):  
Thermal Comfort ◽  
Future Research ◽  
Internal Temperature ◽  
Design Strategies ◽  
External Temperature ◽  
Hot Climate ◽  
Visitor Center ◽  
Building Form ◽  
The Impact ◽  
Moderate Climate

Passive building strategies such as building form, orientation and window ratio can have an essential impact on the indoor temperature. Building form and ordination can obtain heat gains. The designer usually designs buildings with little consideration of heat gains. This study pointed to the influence of building form and orientation in internal temperature in moderate and hot climates. In the present paper, the impact of building orientation on the indoor thermal comfort conditions expressed in terms of internal temperature is numerically investigated. This is motivated by required achievement of the thermal comfort conditions in such buildings located on hot climate regions. Moreover, the moderate climate regions are also incorporated in the present study. The numerical simulation is carried out using the TAS EDSL software to assess the optimum form model for a prefab visitor center. The result, in a moderate climate, showed that the ideal direction was obtained when the visitor center faces the south direction. Different models for building orientations have been studied and the results are presented. The results should that the internal temperature was 37.85oC for the currently model orientation and 37.71oC for the other model (known as model D), where the external temperature was 37.9oC. The worst orientations were the west direction for the case study and the east for the D model. In terms of hot climate, the internal temperature decreased by 1.0oC when west-facing. However, models with openings decreased 0.5oC. There are other passive design strategies that can be installed to models which can lead to improving the thermal comfort. The strategies can be considered for further future research.

scholarly journals Evaluation of Green Elements and Thermal Comfort Condition of Assyafaah Mosque, Singapore

2021 ◽  
Vol 8 (2) ◽  
pp. 913-934
Author(s):  
Noor Muhammad Abdul Rahman ◽  
Muhammad Syukri Imran Abdullah ◽  
Chin Haw Lim
Keyword(s):  
Thermal Comfort ◽  
Natural Ventilation ◽  
Energy Use ◽  
Religious Activities ◽  
Humid Climate ◽  
Thermal Discomfort ◽  
Cultural Aspects ◽  
Passive Design ◽  
Passive Strategies ◽  
The Impact

A mosque is a place for worship and religious activities that are traditionally built with a typical design and shape with a dome and minaret as its traditional symbols. The most basic design of a mosque is a simple single-storey rectangular-shaped building with a prayer hall inside it. Design in the past was influenced by social and cultural aspects. However, regional and climatic differences have led to thermal discomfort and unnecessary energy use if the mosque is not properly designed. Therefore, there is a need to consider comprehensive planning and review for passive design to avoid thermal discomfort and excessive use of energy. Assyafaah Mosque in Singapore is one example that considers sustainable elements in its design. While Singapore is located very near to the hot equatorial line, many passive and green features have been integrated into the design and construction of the mosque, and this made it possible to achieve an acceptable thermal condition according to the adaptive and PMV thermal comfort model. The design maximizes the potential of naturally ventilated design with other passive strategies which allow for both thermal comfort and energy saving. This paper aims to study the impact of natural ventilation and other passive design decisions on the thermal comfort of the Assyafaah mosque in a hot and humid climate.

The influence of the addition of ground olive stone on the thermo-mechanical behavior of compressed earth blocks

2020 ◽  
Vol 108 (2) ◽  
pp. 203
Author(s):  
Samia Djadouf ◽  
Nasser Chelouah ◽  
Abdelkader Tahakourt
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Mechanical Behavior ◽  
Agricultural Waste ◽  
Hydraulic Press ◽  
Dry Density ◽  
Olive Stone ◽  
Compressed Earth Blocks ◽  
Clay Matrix ◽  
Earth Blocks

Sustainable development and environmental challenges incite to valorize local materials such as agricultural waste. In this context, a new ecological compressed earth blocks (CEBS) with addition of ground olive stone (GOS) was proposed. The GOS is added as partial clay replacement in different proportions. The main objective of this paper is to study the effect of GOS levels on the thermal properties and mechanical behavior of CEB. We proceeded to determining the optimal water content and equivalent wet density by compaction using a hydraulic press, at a pressure of 10 MPa. The maximum compressive strength is reached at 15% of the GOS. This percentage increases the mechanical properties by 19.66%, and decreases the thermal conductivity by 37.63%. These results are due to the optimal water responsible for the consolidation and compactness of the clay matrix. The substitution up to 30% of GOS shows a decrease of compressive strength and thermal conductivity by about 38.38% and 50.64% respectively. The decrease in dry density and thermal conductivity is related to the content of GOS, which is composed of organic and porous fibers. The GOS seems promising for improving the thermo-mechanical characteristics of CEB and which can also be used as reinforcement in CEBS.

Investigating the Impact of Ornamental Plants Correlated with Indoor Thermal Comfort and Eco-Energy

2017 ◽  
Vol 8 (5) ◽  
pp. 221
Author(s):  
Sugiono Sugiono ◽  
Suluh E. Swara ◽  
Wisnu Wijanarko ◽  
Dwi H. Sulistyarini
Keyword(s):  
Thermal Comfort ◽  
Ornamental Plants ◽  
Indoor Thermal Comfort ◽  
The Impact

scholarly journals Urban Heat Islands and Thermal Comfort: A Case Study of Zorrotzaurre Island in Bilbao

2021 ◽  
Vol 13 (11) ◽  
pp. 6106
Author(s):  
Irantzu Alvarez ◽  
Laura Quesada-Ganuza ◽  
Estibaliz Briz ◽  
Leire Garmendia
Keyword(s):  
Thermal Comfort ◽  
Heat Waves ◽  
Urban Environments ◽  
Urban Heat Islands ◽  
Extreme Weather Events ◽  
Climate Index ◽  
Physiological Equivalent Temperature ◽  
Heat Islands ◽  
The North ◽  
The Impact

This study assesses the impact of a heat wave on the thermal comfort of an unconstructed area: the North Zone of the Island of Zorrotzaurre (Bilbao, Spain). In this study, the impact of urban planning as proposed in the master plan on thermal comfort is modeled using the ENVI-met program. Likewise, the question of whether the urbanistic proposals are designed to create more resilient urban environments is analyzed in the face of increasingly frequent extreme weather events, especially heat waves. The study is centered on the analysis of temperature variables (air temperature and average radiant temperature) as well as wind speed and relative humidity. This was completed with the parameters of thermal comfort, the physiological equivalent temperature (PET) and the Universal Temperature Climate Index (UTCI) for the hours of the maximum and minimum daily temperatures. The results demonstrated the viability of analyzing thermal comfort through simulations with the ENVI-met program in order to analyze the behavior of urban spaces in various climate scenarios.

scholarly journals Influence of Masks Protecting against SARS-CoV-2 on Thermal Comfort

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3315
Author(s):  
Ewa Zender-Świercz ◽  
Marek Telejko ◽  
Beata Galiszewska
Keyword(s):  
Thermal Comfort ◽  
Public Spaces ◽  
Point Of View ◽  
The Other ◽  
Health Policies ◽  
Thermal Manikin ◽  
Public Health Policies ◽  
Protective Shield ◽  
Full Face ◽  
The Impact

Due to the spread of the SARS-CoV-2 virus, most countries have tightened their public health policies. One way to limit the spread of the virus is to make mouth and nose cover compulsory in public spaces. The article presents the impact of wearing masks on the perception of thermal comfort. The following masks were analysed: FFP2, cotton, medical, PM2.5, half-face protective shield plastic and full-face protective shield plastic. The research was carried out for two scenarios of an ambient temperature: −20 and 30 °C. A thermal manikin was used for the tests. In the case of when a temperature equals 20 °C, the dry masks increase comfort, both general and local, while wet masks reduce comfort. On the other hand, at 30 °C, only wet masks do not increase discomfort. In addition, moist masks require less heat flux to achieve a certain skin temperature. However, it should be remembered that it is not advisable to wet the masks from the health point of view.

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