Impact of urban morphology on urban microclimate and building energy loads

Albedo is the measure of the ratio of solar radiation reflected by the Earth’s surface. High-albedo reflective surfaces absorb less energy and reflect more shortwave radiation. The change in radiative energy balance at the top-of-atmosphere (TOA), which is called radiative forcing (RF), reduces nearby air temperatures and influences the surrounding building energy demand (BED). The impact of reflective surfaces on RF and BED has been investigated separately by researchers through modeling and observational studies, however, no one has compared RF and BED impacts under the same context and the net effect of these two phenomena remains unclear. This paper presents a comprehensive approach to assess the net impacts of pavement albedo modification strategies in selected urban neighborhoods. We apply an adapted analytical model for RF and a hybrid model framework combining two different models for BED to estimate the impacts of increasing pavement albedo from 0.1 to 0.3 for different urban neighborhoods in Boston and Phoenix. The impact of several context-specific factors, including location, urban morphology, shadings etc., are taken into account in the models. Comparative analysis reveals that the net impact of changing pavement albedo can vary from one neighborhood to another. In Phoenix downtown, reflective pavements create net global warming potential burdens, while increasing pavement albedo results in potential savings in the Boston downtown area. This work provides insights into pavement albedo impacts at urban scale and supports more informed decisions on pavement designs that save energy and counteract some of the effects of global warming.

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Impact of Urban Morphology on Infiltration-Induced Building Energy Consumption

Energies ◽

10.3390/en9030177 ◽

2016 ◽

Vol 9 (3) ◽

pp. 177 ◽

Cited By ~ 8

Author(s):

Andrius Jurelionis ◽

Demetri Bouris

Keyword(s):

Energy Consumption ◽

Building Energy ◽

Urban Morphology ◽

Building Energy Consumption

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A method to account for the urban microclimate on the creation of ‘typical weather year’ datasets for building energy simulation, using stochastically generated data

Energy and Buildings ◽

10.1016/j.enbuild.2018.01.016 ◽

2018 ◽

Vol 165 ◽

pp. 270-283 ◽

Cited By ~ 15

Author(s):

S. Tsoka ◽

K. Tolika ◽

T. Theodosiou ◽

K. Tsikaloudaki ◽

D. Bikas

Keyword(s):

Building Energy ◽

Energy Simulation ◽

Building Energy Simulation ◽

Urban Microclimate ◽

The Creation

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Study of urban microclimate conditions in a commercial area of an urban centre and the environmental regeneration potential

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/899/1/012017 ◽

2021 ◽

Vol 899 (1) ◽

pp. 012017

Author(s):

Th Rapti ◽

A Kantzioura

Keyword(s):

Geographical Location ◽

Urban Morphology ◽

Specific Humidity ◽

Urban Centre ◽

Urban Microclimate ◽

The Road ◽

Urban Geometry ◽

Commercial Area ◽

Urban Heat ◽

Air Speed

Abstract Urban heat island (UHI) is a phenomenon that affects the urban microclimate. Land use, urban geometry, cover materials, vegetation, the water element and human activities are the most important factors that affect the UHI. This research focused on the study and analysis of the urban microclimate of three sections of a commercial street area that differ in their morphology. The first area includes a stream near the road, the second area includes the purely commercial part of the street and the third area includes the fringes of a hill in (Thessaloniki, “Toumpa”, Gr Lampraki Street). Using the Envimet V4 program, three simulations were performed for the selected study areas for the hottest day of the previous year, August 1, 2020. The values with the largest variations in all three areas were those of relative and specific humidity and finally air speed. The air temperature was higher in relation to the suburban area (UHI) and did not show significant differences in the three study areas. This leads us to the conclusion that the urban morphology, orientation and geographical location of the three study areas played the most important role in shaping the urban microclimate. Finally, is suggested one alternative scenario for optimizing the microclimate in the most burdened area of the three.

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Alteration of Urban Microclimate in Bandung, Indonesia Based on Urban Morphology

Geographia Technica ◽

10.21163/gt_2019.141.35 ◽

2019 ◽

Vol 14 (special) ◽

pp. 213-220

Author(s):

Beta PARAMITA ◽

Wayan SUPARTA

Keyword(s):

Urban Morphology ◽

Urban Microclimate

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Basic Principles, Most Common Computational Tools, and Capabilities for Building Energy and Urban Microclimate Simulations

Energies ◽

10.3390/en14206707 ◽

2021 ◽

Vol 14 (20) ◽

pp. 6707

Author(s):

George M. Stavrakakis ◽

Dimitris Al. Katsaprakakis ◽

Markos Damasiotis

Keyword(s):

Simulation Models ◽

Building Energy ◽

Urban Microclimate ◽

Comprehensive Overview ◽

Basic Principles ◽

Computational Tools ◽

Simulation Tools ◽

Urban Heat

This paper presents basic principles of built-environment physics’ modelling, and it reviews common computational tools and capabilities in a scope of practical design approaches for retrofitting purposes. Well-established simulation models and methods, with applications found mainly in the international scientific literature, are described by means of strengths and weaknesses as regards related tools’ availability, easiness to use, and reliability towards the determination of the optimal blends of retrofit measures for building energy upgrading and Urban Heat Island (UHI) mitigation. The various characteristics of computational approaches are listed and collated by means of comparison among the principal modelling methods as well as among the respective computational tools that may be used for simulation and decision-making purposes. Insights of coupling between building energy and urban microclimate models are also presented. The main goal was to provide a comprehensive overview of available simulation methods that can be used at the early design stages for planning retrofitting strategies and guiding engineers and technical professionals through the simulation tools’ options oriented to the considered case study.

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Microclimate and urban morphology effects on building energy demand in different European cities

Energy and Buildings ◽

10.1016/j.enbuild.2020.110129 ◽

2020 ◽

Vol 224 ◽

pp. 110129

Author(s):

A. Boccalatte ◽

M. Fossa ◽

L. Gaillard ◽

C. Menezo

Keyword(s):

Energy Demand ◽

Building Energy ◽

Urban Morphology ◽

European Cities

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A Numerical Study on the Correlation between Sky View Factor and Summer Microclimate of Local Climate Zones

Atmosphere ◽

10.3390/atmos10080438 ◽

2019 ◽

Vol 10 (8) ◽

pp. 438 ◽

Cited By ~ 2

Author(s):

Tong Lyu ◽

Riccardo Buccolieri ◽

Zhi Gao

Keyword(s):

Wind Speed ◽

Thermal Comfort ◽

Numerical Study ◽

Local Effect ◽

Urban Morphology ◽

View Factor ◽

Urban Microclimate ◽

Local Climate ◽

Sky View Factor ◽

Local Climate Zones

In the context of urbanization, research on urban microclimate and thermal comfort has become one of the themes of eco-city design. Sky view factor (SVF), one of the parameters of urban spatial form, combines multiple morphological information, such as plane opening, aspect ratio, and building density and has an important impact on the urban microclimate. However, there is still no clear research conclusion on the correlation between SVF and microclimate. In this paper, nine Local Climate Zone (LCZ) models are used and typical summer meteorological conditions of Nanjing are applied as an attempt to partially fill this gap. The calculated microclimate and thermal comfort indices include air temperature (AT), surface temperature (ST), relative humidity (RH), wind speed (WS), mean radiant temperature (MRT), and predicted mean vote (PMV). Results show that the local effect of urban morphology on thermal comfort can be retrieved from the use of comprehensive parameters such as SVF (which takes into account the building height, layout, and density) whose distribution in the investigated models showed to be correlated with MRT, so did PMV under low wind speed conditions.

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Quantifying Impacts of Urban Microclimate on a Building Energy Consumption—A Case Study

Sustainability ◽

10.3390/su11184921 ◽

2019 ◽

Vol 11 (18) ◽

pp. 4921 ◽

Cited By ~ 3

Author(s):

Jiying Liu ◽

Mohammad Heidarinejad ◽

Saber Khoshdel Nikkho ◽

Nicholas W. Mattise ◽

Jelena Srebric

Keyword(s):

Energy Consumption ◽

Convective Heat Transfer Coefficient ◽

Infiltration Rate ◽

Building Energy ◽

Coefficient Of Performance ◽

Local Temperature ◽

Urban Microclimate ◽

Cooling Systems ◽

College Park ◽

Building Cooling

This paper considered an actual neighborhood to quantify impacts of the local urban microclimate on energy consumption for an academic building in College Park, USA. Specifically, this study accounted for solar irradiances on building and ground surfaces to evaluate impacts of the local convective heat transfer coefficient (CHTC), infiltration rate, and coefficient of performance (COP) on building cooling systems. Using computational fluid dynamics (CFD) allowed for the calculation of local temperature and velocity values and implementation of the local variables in the building energy simulation (BES) model. The discrepancies among the cases with different CHTCs showed slight influence of CHTCs on sensible load, in which the maximum variations existed 1.95% for sensible cooling load and 3.82% for sensible heating load. The COP analyses indicated windward wall and upstream roof are the best locations for the installation of these cooling systems. This study used adjusted infiltration rate values that take into account the local temperature and velocity. The results indicated the annual cooling and heating energy increased by 2.67% and decreased by 2.18%, respectively.

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The Vertical City Weather Generator (VCWG v1.0.0)

10.5194/gmd-2019-176 ◽

2019 ◽

Cited By ~ 1

Author(s):

Mohsen Moradi ◽

Benjamin Dyer ◽

Amir Nazem ◽

Manoj K. Nambiar ◽

M. Rafsan Nahian ◽

...

Keyword(s):

Wind Speed ◽

Potential Temperature ◽

Building Energy ◽

Energy Model ◽

Weather Generator ◽

Specific Humidity ◽

Weather Data ◽

Rural Site ◽

Vertical Diffusion ◽

Urban Microclimate

Abstract. The Vertical City Weather Generator (VCWG) is a computationally efficient urban microclimate model developed to predict temporal and vertical variation of temperature, wind speed, and specific humidity. It is composed of various sub models: a rural model, an urban microclimate model, and a building energy model. In a nearby rural site, a rural model is forced with weather data to solve a vertical diffusion equation to calculate vertical potential temperature profiles using a novel parameterization. The rural model also calculates a horizontal pressure gradient. The rural model outputs are then forced on a vertical diffusion urban microclimate model that solves vertical transport equations for momentum, temperature, and specific humidity. The urban microclimate model is also coupled to a building energy model using feedback interaction. The aerodynamic and thermal effects of urban elements and vegetation are considered in VCWG. To evaluate the VCWG model, a microclimate field campaign was held in Guelph, Canada, from 15 July 2018 to 5 September 2018. The meteorological measurements were carried out under a comprehensive set of wind directions, wind speeds, and thermal stability conditions in both the rural and the nearby urban areas. The model evaluation indicated that the VCWG predicted vertical profiles of meteorological variables in reasonable agreement with field measurements for selected days. In comparison to measurements, the overall model biases for potential temperature, wind speed, and specific humidity were within 5 %, 11 %, and 7 %, respectively. The performance of the model was further explored to investigate the effects of urban configurations such as plan and frontal area densities, varying levels of vegetation, seasonal variations, different climate zones, and time series analysis on the model predictions. The results obtained from the explorations were reasonably consistent with previous studies in the literature, justifying the reliability and computational efficiency of VCWG for operational urban development projects.

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