Study on the Influence of Piloti on Mean Radiant Temperature in Residential Blocks by 3-D Unsteady State Heat Balance Radiation Calculation

Piloti is commonly used in tropical and subtropical climate zones to get high wind velocity and create shadowed areas in order to optimize the living environment of residential blocks,but there are few studies to reveal the influence of piloti on the radiant environment of residential blocks systematically. Taking the city of Guangzhou as an example,using 3-D Unsteady State Heat Balance Radiation Calculation Method,this paper shows that the mean radiant temperature( MRT) under piloti area increases with the increase of piloti ratio,and especially when piloti ratio is equal to 100%,the MRT increase trend becomes sharp. The MRT of exposed area decreases with the increase of piloti ratio,especially when piloti ratio reaches 100%,the decrease trend of MRT becomes sharp,which offers the reference for the study on piloti design in subtropical climate zones and further research on living environment by CFD simulation in residential blocks.

Influence of urban morphological factors on building energy consumption combined with photovoltaic potential: A case study of residential blocks in central China

Studies on urban energy have been growing in interest,and past research has mostly been focused on studies of urban solar potential or urban building energy consumption independently.However,holistic research on the combination of urban building energy consumption and solar potential at the urban block-scale is required in order to minimize energy use and maximize solar power generation simultaneously.The aim of this study is to comprehensively evaluate the impact of urban morphological factors on photovoltaic(PV)potential and building energy consumption.Firstly,58 residential blocks were classified into 6 categories by k-means clustering.Secondly,3 energy performance factors,which include the energy use intensity(EUI),the energy use intensity combined with PV potential(EUI-PV),and photovoltaic substitution rate(PSR)were calculated for these blocks.The study found that the EUI of the Small Length&High Height blocks was the lowest at around 30 kWh/(m^(2)·y),while the EUI-PV of the Small Length&Low Height blocks was the lowest at around 4.45 kWh/(m^(2)·y),and their PSR was the highest at 87%.Regression modelling was carried out,and the study concluded that the EUI of residential blocks was mainly affected by shape factor,building density and floor area ratio,while EUI-PV and PSR were mainly affected by height and sky view factor.In this study,the results and developed methodology are helpful to provide recommendations and strategies for sustainable planning of residential blocks in central China.

Investigation of typical residential block typologies and their impact on pedestrianlevel microclimate in summers in Nanjing, China

The morphology of urban residential blocks in China,which is strictly affected by regulations,can potentially improve or deteriorate microclimates.This paper first proposes a framework for identifying typical residential block typologies using Nanjing as an example.A thorough investigation,consisting of 114 samples,was conducted,and 18 typical residential block typologies were summarized.Second,3D non-isothermal numerical simulations were performed on the hottest days of summer using the ENVI-met.The effect of morphological indices on the microclimate at the pedestrian level was explored using statistical methods and a novel graphic method named m-SpaceMate.The results revealed a strong correlation between the urban heat island intensity(UHII),mean radiation temperature,and universal thermal climate index(UTCI)and floor area ratio(FAR),as well as between wind velocity(U)and building coverage ratio(BCR).A significant increase in FAR(by approximately 1.0)can result in a low UTCI that was driven by MRT and shading conditions.Six-floor blocks,with FAR between 1.8 and 2.1,had a better overall thermal environment(except for lower U)than that of 11-floor blocks.When considering a similar BCR,blocks with slab-type buildings tended to have a U that was higher by approximately 30%.