scholarly journals A short review on passive strategies applied to minimise the building cooling loads in hot locations

2021 ◽  
Vol 15 (2) ◽  
pp. 20-30
Author(s):  
Qudama Al-Yasiri ◽  
Márta Szabó
Keyword(s):  
Energy Demand ◽  
Natural Ventilation ◽  
Phase Change Materials ◽  
Weather Conditions ◽  
Short Review ◽  
Building Energy ◽  
Passive Strategies ◽  
Shading Devices ◽  
Building Cooling ◽  
Cooling Loads

Cooling and air-conditioning systems are responsible for the highest energy consumption in buildings located in hot areas. This high share does not only increase the building energy demand cost but also increases the environmental impact, the topmost awareness of the modern era. The development of traditional systems and reliance on renewable technologies have increased drastically in the last century but still lacks economic concerns. Passive cooling strategies have been introduced as a successful option to mitigate the energy demand and improve energy conservation in buildings. This paper shed light on some passive strategies that could be applied to minimise building cooling loads to encourage the movement towards healthier and more energy-efficient buildings. For this purpose, seven popular passive technologies have been discussed shortly: multi-panned windows, shading devices, insulations, green roofing, phase change materials, reflective coatings, and natural ventilation using the windcatcher technique. The analysis of each strategy has shown that the building energy could be improved remarkably. Furthermore, adopting more passive strategies can significantly enhance the building thermal comfort even under severe weather conditions.

scholarly journals Revealing the Impacts of Passive Cooling Techniques on Building Energy Performance: A Residential Case in Hong Kong

2020 ◽  
Vol 10 (12) ◽  
pp. 4188 ◽  
Author(s):  
Chuan-Rui Yu ◽  
Han-Sen Guo ◽  
Qian-Cheng Wang ◽  
Rui-Dong Chang
Keyword(s):  
Hong Kong ◽  
Energy Conservation ◽  
Energy Demand ◽  
Natural Ventilation ◽  
Phase Change Materials ◽  
Residential Buildings ◽  
Building Energy ◽  
Energy Performance ◽  
Passive Cooling ◽  
Total Energy Consumption

Environmental concerns and growing energy costs raise the importance of sustainable development and energy conservation. The building sector accounts for a significant portion of total energy consumption. Passive cooling techniques provide a promising and cost-efficient solution to reducing the energy demand of buildings. Based on a typical residential case in Hong Kong, this study aims to analyze the integration of various passive cooling techniques on annual and hourly building energy demand with whole building simulation. The results indicate that infiltration and insulation improvement are effective in regard to energy conservation in buildings, while the effectiveness of variations in building orientation, increasing natural ventilation rate, and phase change materials (PCM) are less significant. The findings will be helpful in the passive house standard development in Hong Kong and contribute to the further optimization work to realize both energy efficiency and favorably built environments in residential buildings.

scholarly journals Building Energy an Simulation Model for Analyzing Energy Saving Options of Multi-Span Greenhouses

2020 ◽  
Vol 10 (19) ◽  
pp. 6884
Author(s):  
Adnan Rasheed ◽  
Cheul Soon Kwak ◽  
Hyeon Tae Kim ◽  
Hyun Woo Lee
Keyword(s):  
Energy Demand ◽  
Natural Ventilation ◽  
Thermal Environment ◽  
Dynamic Control ◽  
Weather Conditions ◽  
Building Energy ◽  
Design Parameters ◽  
Heating And Cooling ◽  
North Wall ◽  
Local Weather

This study proposes a multi-span greenhouse Building Energy Simulation (BES) model using a Transient System Simulation (TRNSYS)-18 program. A detailed BES model was developed and validated to simulate the thermal environment in the greenhouse under different design parameters for the multi-span greenhouse. Validation of the model was carried out by comparing the results from computed and experimental greenhouse internal temperatures. The statistical analyses produced an R2 value of 0.84, a root mean square error (RMSE) value of 1.8 °C, and a relative (r)RMSE value of 6.7%, showing good agreement between computed and experimental results. The validated proposed BES model was used to evaluate the effect of multi-span greenhouse design parameters including thermal screens, number of screens, orientation, covering materials, double glazing, north-wall insulation, roof geometry, and natural ventilation, on the annual energy demand of the greenhouse, subjected to Taean Gun (latitude 36.88° N, longitude 126.24° E), Chungcheongnam-do, South Korea winter and summer season weather conditions. Additionally, the proposed BES model is capable of evaluating multi-span greenhouse design parameters with daily and seasonal dynamic control of thermal and shading screens, natural ventilation, as well as heating and cooling set-points. The TRNSYS 18 program proved to be highly flexible for carrying out simulations under local weather conditions and user-defined design and control of the greenhouse. The statistical analysis of validated results should encourage the adoption of the proposed model when the underlying aim is to evaluate the design parameters of multi-span greenhouses considering local weather conditions and specific needs.

Numerical Study of Optimal Building Scales With Low Cooling Load in Both Hot and Mild Climatic Regions

Solar Energy ◽  
2006 ◽  
Author(s):  
Zhiqiang Zhai
Keyword(s):  
Los Angeles ◽  
Natural Ventilation ◽  
Numerical Study ◽  
Energy Requirement ◽  
Building Energy ◽  
Energy Performance ◽  
Climatic Regions ◽  
Scale Ratio ◽  
Building Cooling ◽  
Energy Efficient Building

Natural ventilation is one of the primary strategies for buildings in hot and mild climatic regions to reduce building cooling energy requirement. This paper uses a building energy simulation program and a computational fluid dynamics program to investigate the influence of building scales on building cooling energy consumption with and without natural ventilation. The study examines the energy performance of buildings with different L/W and H/W ratios in both Miami, FL and Los Angeles, CA. The simulation results show the varying trends of natural ventilation potential with increased building scale ratio of L/W and H/W. The comparison of the predicted energy consumptions for twenty buildings discloses the most energy-efficient building scales for rectangular-shape buildings in both hot and mild climates with and without natural ventilation. The study indicates that natural ventilation is more effective in mild climates than in hot climates, which may save cooling energy by 50% and vent fan energy by 70%. The paper analyzes the most suitable seasons for natural ventilation in Miami and Los Angeles. Further simulations indicate that extra cooling benefits associated with more natural ventilation cannot compensate additional heat gains through larger windows.

scholarly journals Development of a Building Energy Simulation Model for Control of Multi-Span Greenhouse Microclimate

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1236
Author(s):  
Adnan Rasheed ◽  
Cheul Soon Kwak ◽  
Wook Ho Na ◽  
Jong Won Lee ◽  
Hyeon Tae Kim ◽  
...  
Keyword(s):  
Simulation Model ◽  
Natural Ventilation ◽  
Winter Season ◽  
Weather Conditions ◽  
Building Energy ◽  
Energy Simulation ◽  
Building Energy Simulation ◽  
Proposed Model ◽  
Heating Loads ◽  
Maximum Heating

In this study, we propose a building energy simulation model of a multi-span greenhouse using a transient system simulation program to simulate greenhouse microenvironments. The proposed model allows daily and seasonal control of screens, roof vents, and heating setpoints according to crop needs. The proposed model was used to investigate the effect of different thermal screens, natural ventilation, and heating setpoint controls on annual and maximum heating loads of a greenhouse. The experiments and winter season weather conditions of greenhouses in Taean Gun (latitude 36.88° N, longitude 126.24° E, elevation 45 m) Chungcheongnam-do, South Korea was used for validation of our model. Nash–Sutcliffe efficiency coefficients of 0.87 and 0.71 showed good correlation between the computed and experimental results; thus, the proposed model is appropriate for performing greenhouse thermal simulations. The results showed that the heating loads of the triple-layered screen were 70% and 40% lower than that of the single-screen and double-screen greenhouses, respectively. Moreover, the maximum heating loads without a screen and for single-, double-, and the triple-layered screens were 0.65, 0.46, 0.41, and 0.34 MJ m−2, respectively. The analysis of different screens showed that Ph-77 (shading screen) combined with Ph-super (thermal screen) had the least heating requirements. The heating setpoint analysis predicted that using the designed day- and nighttime heating control setpoints can result in 3%, 15%, 14%, 15%, and 40% less heating load than when using the fixed value temperature control for November, December, January, February, and March, respectively.

scholarly journals Parametric Study on Determining Optimum Shading Techniques for Urban High-Rise Dwellings

Urban Science ◽  
2019 ◽  
Vol 3 (3) ◽  
pp. 85
Author(s):  
Shorouk Omar Elshiwihy ◽  
Hassam Nasarullah Chaudhry
Keyword(s):  
Energy Consumption ◽  
Parametric Study ◽  
Energy Demand ◽  
Natural Ventilation ◽  
Building Design ◽  
Sustainable Building ◽  
High Rise ◽  
Optimum Energy ◽  
Computational Fluid Dynamics Cfd ◽  
Shading Devices

Shading techniques constitute one of the most passive, beneficial strategies for reducing energy consumption in urban dwellings. Shading affects many factors, for example, the solar gains and radiations falling on the façade, which are considered the most significant in increasing the cooling energy demand in hot climates. This paper conducts a parametric study on external and internal shading devices and establishes their impact on energy consumption, daylight levels, and ventilation. The work was conducted using Integrated Environmental Simulation Virtual Environment (IES-VE) and Computational Fluid Dynamics (CFD) numerical methods. The results revealed that optimised shading can influence savings in terms of energy and cooling, in addition to the enhancement of daylighting and reduction of glare. After studying all these factors associated with the different shading techniques investigated, the findings revealed that all shades affect the energy, daylight and ventilation parameters positively. However, despite all external and internal shadings showing improvements, the egg crate shade was determined as that which provided the optimum energy saving, while enhancing daylight and improving natural ventilation for a sustainable building design.

scholarly journals Energy Analysis of a Dual-Source Heat Pump Coupled with Phase Change Materials

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2933
Author(s):  
Michele Bottarelli ◽  
Francisco Javier González Gallero
Keyword(s):  
Phase Change ◽  
Heat Pump ◽  
Energy Demand ◽  
Phase Change Materials ◽  
Weather Conditions ◽  
Heat Pumps ◽  
Ground Heat Exchangers ◽  
Heating And Cooling ◽  
Air Source Heat Pump ◽  
Dual Source

Installation costs of ground heat exchangers (GHEs) make the technology based on ground-coupled heat pumps (GCHPs) less competitive than air source heat pumps for space heating and cooling in mild climates. A smart solution is the dual source heat pump (DSHP) which switches between the air and ground to reduce frosting issues and save the system against extreme temperatures affecting air-mode. This work analyses the coupling of DSHP with a flat-panel (FP) horizontal GHE (HGHE) and a mixture of sand and phase change materials (PCMs). From numerical simulations and considering the energy demand of a real building in Northern Italy, different combinations of heat pumps (HPs) and trench backfill material were compared. The results show that PCMs always improve the performance of the systems, allowing a further reduction of the size of the geothermal facility. Annual average heat flux at FP is four times higher when coupled with the DSHP system, due to the lower exploitation. Furthermore, the enhanced dual systems are able to perform well during extreme weather conditions for which a sole air source heat pump (ASHP) system would be unable either to work or perform efficiently. Thus, the DSHP and HGHE with PCMs are robust and resilient alternatives for air conditioning.

scholarly journals A Methodology to Investigate the Deviations between Simple and Detailed Dynamic Methods for the Building Energy Performance Assessment

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6217
Author(s):  
Ilaria Ballarini ◽  
Andrea Costantino ◽  
Enrico Fabrizio ◽  
Vincenzo Corrado
Keyword(s):  
Energy Demand ◽  
Dynamic Models ◽  
Building Energy ◽  
Energy Performance ◽  
Transfer Coefficients ◽  
Study Approach ◽  
Heat Transfer Coefficients ◽  
Heating And Cooling ◽  
Cooling Loads ◽  
Physical Phenomena

The research investigates the validity of the simple hourly method, as introduced by the EN ISO 52016-1 standard, for the assessment of the building energy demand for heating and cooling, by comparing it with a detailed dynamic model (EnergyPlus). A new methodology is provided to identify and quantify the causes of deviations between the models. It consists in the split of the contributions of the air heat balance (AHB) equation by dynamic driving force, and in the adoption of consistency options of the modeling parameters related to specific physical phenomena. A case study approach is adopted in the article to achieve the research objective. The results show that the deviations in the heating and cooling loads between the two calculation methods can be mainly ascribed to the use of different surface heat transfer coefficients, and to a different modeling of the extra thermal radiation to the sky. Providing a methodology to validate the calculation method, this work is intended to contribute to the enhancement of the use of simple dynamic models and to the improvement of the standardization activity.

Computational Analysis to Design Energy Efficient Built Environments

2012 ◽  
Author(s):  
Guy Abou-Nassar ◽  
Zahed Siddique ◽  
Lee Fithian
Keyword(s):  
Natural Ventilation ◽  
Stokes Equations ◽  
Weather Conditions ◽  
Navier Stokes ◽  
Ambient Conditions ◽  
Navier Stokes Equations ◽  
Double Skin ◽  
Set Up ◽  
Shading Devices ◽  
Volume Method

Double skin facades (DSF) provide a means of enhancing the energy saving capabilities of buildings. By being able to respond dynamically to changing ambient conditions using natural ventilation, shading devices, and/or thermal insulation devices or strategies, DSFs are being incorporated into modern architecture and even retrofitted in some older structures to reduce the energy required to balance the load input into the building. Utilizing a general building model and weather conditions and integrating various designs for DSFs, a comparative study can be made to support or oppose the different designs changes being made. The analysis of the set-up will be performed by Fluent, a computational fluid dynamics (CFD) software. Fluent will solve for the Navier-Stokes equations and turbulent flow using the finite volume method. These results show that the energy necessary to power the HVAC system decreases with certain configurations.

scholarly journals Application of Phase Change Materials and Conventional Thermal Mass for Control of Roof-Generated Cooling Loads

2020 ◽  
Vol 10 (19) ◽  
pp. 6875
Author(s):  
Jan Kośny ◽  
William Anthony Miller ◽  
David Yarbrough ◽  
Elisabeth Kossecka ◽  
Kaushik Biswas
Keyword(s):  
Energy Demand ◽  
Phase Change Materials ◽  
Peak Load ◽  
Thermal Response ◽  
Climatic Conditions ◽  
Thermal Mass ◽  
Design Strategies ◽  
Response Characteristics ◽  
Intense Solar Radiation ◽  
Cooling Loads

Among all of the internal fabric and external enclosure components of buildings, sloped roofs and adjacent attics are often the most dynamic areas. Roofs are exposed to high temperature fluctuations and intense solar radiation that are subject to seasonal changes in climatic conditions. Following the currently rising interests in demand-side management, building energy dynamics, and the thermal response characteristics of building components, this paper contains unpublished results from past studies that focused on innovative roof and attic configurations. The authors share unique design strategies that yield significant reduction of daytime roof peak temperatures, thermal-load shavings, and up to a ten-hour shift of the peak load period. Furthermore, advance configurations of the roofs and attics that are discussed in this paper enable over 90% reductions in roof-generated peak-hour cooling loads and sometimes close to 50% reductions in overall roof-generated cooling loads as compared with traditionally constructed roofs with the same or similar levels of thermal insulation. It is expected that the proposed new roof design schemes could support the effective management of dynamic energy demand in future buildings.

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