Impacts of Microclimate Conditions on the Energy Performance of Buildings in Urban Areas

Abstract

Urbanization trends have changed the morphology of cities in the past decades. Complex urban areas with wide variations in built density, layout typology, and architectural form have resulted in more complicated microclimate conditions. Microclimate conditions affect the energy performance of buildings and bioclimatic design strategies as well as a high number of engineering applications. However, commercial energy simulation engines that utilize widely-available mesoscale weather data tend to underestimate these impacts. These weather files, which represent typical weather conditions at a location, are mostly based on long-term metrological observations and fail to consider extreme conditions in their calculation. This paper aims to evaluate the impacts of hourly microclimate data in typical and extreme climate conditions on the energy performance of an office building in two different urban areas. Results showed that the urban morphology can reduce the wind speed by 27% and amplify air temperature by more than 14%. Using microclimate data, the calculated outside surface temperature, operating temperature and total energy demand of buildings were notably different to those obtained using typical regional climate model (RCM)–climate data or available weather files (Typical Meteorological Year or TMY), i.e., by 61%, 7%, and 21%, respectively. The difference in the hourly peak demand during extreme weather conditions was around 13%. The impact of urban density and the final height of buildings on the results are discussed at the end of the paper.

Applicability of Feng Shui Thoughts for Sustainable Space Planning and Evaluation in Korea Verified Using Three-Dimensional Digital Mapping and Simulations

“…As such, the wind flow pattern often becomes complicated when external elements are being used. Thus, when wind speed becomes lower, the availability of the air flow will be decreased [32]. In comparison, the ecological architecture additionally tends to emphasize wind power control by using various active components, such as machinery and systematic equipment, to optimize energy efficiency.…”

“…The ecosystem with the biosphere is often used as a wind barrier. It plays a role as a windbreak [32,34]. That is, both theories utilize a control device for natural environments, although feng shui thoughts tend to have relatively more considerations for the biosphere while confirming the core concepts and/or information in terms of the local ecosystem and emphasizing harmonization with the existing landscape, as exemplified in Figure 8 [14,31].…”

Impact Analysis of Urban Morphology on Residential District Heat Energy Demand and Microclimate Based on Field Measurement Data

“…Different urban morphologies could create different situations in their microclimates, in turn, influencing the building's energy consumption performance [18]. Therefore, the building energy simulation model may lead to inaccuracies in a building's energy use simulation without capturing the impact of urban morphology [19,20]. Neglect of the urban microclimate effect may lead to an overestimation of a building's annual heating by 20% and underestimation of cooling load by 30% by EnergyPlus [21].…”

Optimization of building form and its fenestration in response to microclimate conditions of an urban area

“…For CFD simulations, a developed method by Javanroodi was adopted using a verified Autodesk CFD and ANSYS Fluent coupled approach. Readers are referred to [18,19] for more explanation on the adopted method including boundary conditions, governing equations, and major inputs for CFD simulation. For computational domain, standards such as AIJ and COST [20,21] (in which distances from inlet and sides of the domain to model should not be less than 5H and at least 10H from behind the model) were adopted.…”