scholarly journals An overview on passive cooling systems in green building architectures

2019 ◽  
pp. 01-15
Author(s):  
Jani DB
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Heat Dissipation ◽  
Green Building ◽  
Passive Cooling ◽  
High Grade ◽  
Cooling Systems ◽  
Mechanical Methods ◽  
Passive Cooling Systems ◽  
The Impact

The continuous progressive demand of building construction raises many issues regarding supply of high grade electricity. It creates many environmental issues for its production like as global warming. So, the passive cooling buildings were welcomed to respond variable climate in order to reduce energy supply for thermal comfort as well as health of building users. The aim of designing a passive building is to take best advantage of the regional outdoor ambient conditions. Passive cooling refers to a building architectural approach that mainly goal on heat gain control and heat dissipation in a architectural structure in order to ameliorate the indoor thermal comfort with low or nil energy consumption. Passive cooling systems use non-mechanical methods to sustain a comfortable indoor temperature and are a main aim in extenuating the impact of buildings on the regional environment. The energy consumption in buildings is very much with the anticipation to further increase because of improving standards of leaving and the increase of industrialization. The use of HVAC in building has exponentially rises over the past few decades and quite enough to contribute in the enormous use of high grade electrical energy consumption. This paper reviews various passive cooling techniques used in the green building and their role in providing thermal comfort and its significance in energy conservation with the help of architectural interventions.

scholarly journals When social practices produce space and create passive cooling systems in hot arid region

2022 ◽  
Vol 27 ◽  
pp. 932-944
Author(s):  
Ibtissame Benoudjafer
Keyword(s):  
Thermal Comfort ◽  
Arid Regions ◽  
Passive Cooling ◽  
Thermal Mass ◽  
Cooling Load ◽  
Cooling Systems ◽  
Cooling Strategy ◽  
Main Factors ◽  
Dry Climates ◽  
Passive Cooling Systems

Abstract. Practice social of people is the key to produce space and give a possibility to maintain thermal comfort and energy efficiency. The main objective of this research is to adapt the traditional strategies in the architecture actual, to achieved a thermal comfort and improve on reducing cooling load through the using of vernacular gait. Today, it is necessary to practice these systems in the current or conventional architecture of household. The study is especially for arid cities namely the region of Saoura, in the hot and dry climatic zone in Algeria, considered for this study. Two main factors is considered such as design and urban where taken into account in order to select the appropriate and specific passive cooling strategy. The results show that the passive cooling strategy of courtyard would be appropriate for arid regions, however a high thermal mass would be suitable for construction. In conclusion, this work made it possible to choose a suitable passive cooling strategy for all types of construction in hot and dry climates. Finally, this paper puts forward a set of recommendations to improve the passive design of future buildings in hot and arid climates.  

Impact of Passive Cooling Strategies on Energy Consumption Reduction of Residential Buildings in the Kingdom of Saudi Arabia

2015 ◽  
Author(s):  
Alaa Alaidroos ◽  
Moncef Krarti
Keyword(s):  
Saudi Arabia ◽  
Energy Consumption ◽  
Natural Ventilation ◽  
Residential Buildings ◽  
Evaporative Cooling ◽  
Passive Cooling ◽  
Kingdom Of Saudi Arabia ◽  
Cooling Systems ◽  
End Use ◽  
Passive Cooling Systems

In this paper, passive cooling strategies have been investigated to evaluate their effectiveness in reducing cooling thermal loads and air conditioning energy consumption for residential buildings in Kingdom of Saudi Arabia (KSA). Specifically, three passive cooling techniques have been evaluated including: natural ventilation, downdraft evaporative cooling, and earth tube cooling. These passive cooling systems are applied to a prototypical KSA residential villa model with an improved building envelope. The analysis has been carried using detailed simulation tool for several cities representing different climate conditions throughout KSA. It is found that both natural ventilation and evaporative cooling provide a significant reduction in cooling energy for the prototypical villa located in Riyadh. Natural ventilation alone has reduced the cooling energy end-use by 22% and the total villa energy consumption by 10%, while the evaporative cooling system has resulted in 64% savings in cooling energy end-use and 32% in the total villa energy consumption. When applying both passive cooling systems together to the villa, the cooling energy end-use is significantly reduced by about 84.2% and the total villa energy savings by 62.3% relative to the un-insulated basecase residential building model. Moreover, natural ventilation is found to have a high potential in all KSA climates, while evaporative cooling can be suitable only in hot and dry climates such as Riyadh and Tabuk.

scholarly journals Improving Energy Efficiency by Utilizing Wetted Cellulose Pads in Passive Cooling Systems

Energies ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 369
Author(s):  
Ebrahim Morady ◽  
Madjid Soltani ◽  
Farshad Moradi Kashkooli ◽  
Masoud Ziabasharhagh ◽  
Armughan Al-Haq ◽  
...  
Keyword(s):  
Passive Cooling ◽  
The Novel ◽  
Airflow Velocity ◽  
Cross Sectional ◽  
Cooling Systems ◽  
Good Potential ◽  
Novel Concept ◽  
Passive Cooling Systems ◽  
The Impact ◽  
Psychrometric Chart

The effectiveness of using wetted cellulose pads on improving the performance of two conventional passive cooling systems has been evaluated. First, an experimental design was developed to determine the impact of using a wetted cellulose pad on the temperature and velocity of the airflow. A cellulose pad (7090 model) with a cross-sectional area of 0.5 × 0.5 m2 and three different thicknesses of 10, 15, and 30 cm were selected and tested. The results indicated that using wetted cellulose pads with thicknesses ranging from 10–30 cm decreased the outlet airflow temperature from 11.3 to 13.7 °C on average. For free airflow at velocity 3.5 m/s, the outlet airflow velocity from the wetted cellulose pad decreased to 0.9, 0.7 and 0.6 m/s, respectively, for cellulose pads with thicknesses of 10, 15, and 30 cm. By applying experimental results on a psychrometric chart, the humidity ratio of outlet airflow was obtained between 40–70%. The study established airflow velocity as the critical parameter in passive cooling systems. With the novel concept of combining wetted cellulose pads for passive cooling systems (i.e., wind catchers and induced ventilation), there is good potential to reduce the energy requirements for thermal comfort in buildings in regions with a hot and arid climate.

Wind-Induced Ventilation Techniques for Passive Cooling

2018 ◽  
Vol 3 (7) ◽  
Author(s):  
Ahmad Ridzwan Othman ◽  
Fatin Farhah Muda
Keyword(s):  
Negative Impact ◽  
Wind Pressure ◽  
Passive Cooling ◽  
Indoor Temperature ◽  
Cooling Systems ◽  
Local Climate ◽  
Building Height ◽  
Mechanical Methods ◽  
Ventilation Technique ◽  
Passive Cooling Systems

Passive cooling systems maintained a comfortable indoor temperature using non-mechanical methods, uses less energy and reducing the negative impact on the environment. The aim is to review the wind-induced technique suitable for a hot and humid country like Malaysia. Samples in Petaling Jaya were assessed for their performances and highlight the factors influencing the strengths and the weaknesses. The success of wind-induced ventilation technique depends on the wind velocity and the building height because the wind pressure increases with building height. Other factors that affect the effectiveness of the wind-induced ventilation techniques are shape, size, building orientation and local climate.

Impact of roof shading on building energy performance in warm & humid climatic places of India

2020 ◽  
pp. 50-64
Author(s):  
Kuladeep Kumar Sadevi ◽  
Avlokita Agrawal
Keyword(s):  
Energy Consumption ◽  
Energy Conservation ◽  
Energy Performance ◽  
General Assumption ◽  
Climatic Conditions ◽  
Building Envelope ◽  
Passive Cooling ◽  
Base Case ◽  
U Value ◽  
The Impact

With the rise in awareness of energy efficient buildings and adoption of mandatory energy conservation codes across the globe, significant change is being observed in the way the buildings are designed. With the launch of Energy Conservation Building Code (ECBC) in India, climate responsive designs and passive cooling techniques are being explored increasingly in building designs. Of all the building envelope components, roof surface has been identified as the most significant with respect to the heat gain due to the incident solar radiation on buildings, especially in tropical climatic conditions. Since ECBC specifies stringent U-Values for roof assembly, use of insulating materials is becoming popular. Along with insulation, the shading of the roof is also observed to be an important strategy for improving thermal performance of the building, especially in Warm and humid climatic conditions. This study intends to assess the impact of roof shading on building’s energy performance in comparison to that of exposed roof with insulation. A typical office building with specific geometry and schedules has been identified as base case model for this study. This building is simulated using energy modelling software ‘Design Builder’ with base case parameters as prescribed in ECBC. Further, the same building has been simulated parametrically adjusting the amount of roof insulation and roof shading simultaneously. The overall energy consumption and the envelope performance of the top floor are extracted for analysis. The results indicate that the roof shading is an effective passive cooling strategy for both naturally ventilated and air conditioned buildings in Warm and humid climates of India. It is also observed that a fully shaded roof outperforms the insulated roof as per ECBC prescription. Provision of shading over roof reduces the annual energy consumption of building in case of both insulated and uninsulated roofs. However, the impact is higher for uninsulated roofs (U-Value of 3.933 W/m2K), being 4.18% as compared to 0.59% for insulated roofs (U-Value of 0.33 W/m2K).While the general assumption is that roof insulation helps in reducing the energy consumption in tropical buildings, it is observed to be the other way when insulation is provided with roof shading. It is due to restricted heat loss during night.

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.

scholarly journals Analysis of the Effect of Using External Venetian Blinds on the Thermal Comfort of Users of Highly Glazed Office Rooms in a Transition Season of Temperate Climate—Case Study

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 81 ◽  
Author(s):  
Małgorzata Fedorczak-Cisak ◽  
Katarzyna Nowak ◽  
Marcin Furtak
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Ambient Air ◽  
Temperate Climate ◽  
Cooling Systems ◽  
Clothing Insulation ◽  
Transition Season ◽  
Venetian Blinds ◽  
Research Task ◽  
Office Rooms

Improving the energy efficiency of buildings is among the most urgent social development tasks due to the scale of energy consumption in this industry. At the same time, it is essential to meet high requirements for indoor environmental quality and thermal comfort. The issue of overheating is most often analysed in summer but it also occurs in transition seasons, when the cooling systems do not operate. The paper attempts to evaluate the effectiveness of external mobile shading elements on the microclimate of rooms with large glazed areas in the transition season. Passive solutions, such as shading elements, which limit the increase of indoor temperature, do not always allow the acquisition and maintenance of comfortable solutions for the duration of the season, as demonstrated by the authors. Temporary cooling of the rooms may be necessary to maintain comfortable conditions for the users, or other solutions should be devised to improve comfort (e.g., reduction of clothing insulation characteristics). The novelty of the study consists in the analysis of comfort in a “nearly zero energy consumption” building (NZEB) during a period not analyzed by other scientists. This is a transition period during which heating/cooling systems do not operate. The research task set by the authors involved the assessment of the possibility to reduce office space overheating in the transition season (spring) by using external shading equipment in rooms with large glazed areas. An additional research task aimed at checking the extent to which user behaviour, such as reduction in clothing insulation characteristics, can improve comfort in overheated rooms. The results of the tests reveal that the difference in the ambient air temperature between a room with external venetian blinds and an identical room with no venetian blinds in the transition season, i.e., from 27 March to 6 April 2017, ranged from 12.3 to 2.1 °C. The use of a shading system (external venetian blinds positioned at an angle of 45°) reduced the number of discomfort hours by 92% (during working hours) compared to the room without external venetian blinds. A reduction in the thermal insulation of the clothes worn by people working in the room with no venetian blinds helped to reduce the number of discomfort hours by 31%.

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