The Impact of Canyon Design on the Thermal Environment of the Coastal Area of Selatpanjang City Rahman, B. Post Graduate Department of Architecture Institut Teknologi Sepuluh Nopember Surabaya, Indonesia Defiana, I. Lecturer Department of Architecture Institut Teknologi Sepuluh Nopember Surabaya, Indonesia Dinapradipta, A. Lecturer Department of Architecture Institut Teknologi Sepuluh Nopember Surabaya, Indonesia Abstract— Increasing numbers of building floors in Selatpanjang city provides a double surface for the process of sunlight reflection and air flow barrier on the building canyon environment. Meanwhile, cooling by airflow is highly required along with changes in the physical city which potentially lead to the formation of Urban Heat Islands (UHI). The presence of a link between buildings to the thermal environment performance leads to the need of a study on canyon designs in the different conditions that is affected conditions by the waterfront building barrier. This study is an experimental research conducted using ENVI-met V3.1 software simulation. Canyon design with low H/W value (1.05 and 0.9) produces air temperature of 34.7°C and 35.4°C. There is a difference of 1-2.4°C higher than canyon design with high H/W value. Condition of the implementation of the regulation of Directorate General of Human Settlements (2000), shallow canyon (H/W low) still produces higher air temperature values than the deep canyon (H/W high) but with a small value difference of 0.1°C-0.37°C. Long canyon resulted in lower airflow velocity value changes when compared to short canyon at all altitude levels of 0.78-0.87 m / s versus 1.3-1.46 m/s. with the result that providing a better cooling effect. Keywords— Thermal Environment; Coastal City Area; Urban Canyon Design, Airflow Velocity. I. INTRODUCTION In the last few years, along with societal development and dynamics, Selatpanjang City has undergone an increase in regional function. Initially only functioning as a settlement, however due to the rapid growth of several urban areas, the regional function has grown to include trade services, offices and also industries- to name a few. This condition has led to the emergence of new buildings with different heights that resulted in changes in the geometric design of building canyons. The changes that occured in the design of the building canyons have the effect of not bearing enough space for heat release conducted through the airflow between. Meanwhile, cooling by airflow is highly required along with changes in the physical city which potentially lead to the formation of Urban Heat Islands (UHI), which is the condition of increased temperature in central urban areas [1]. Based on the explanation above, this study evaluates the thermal environmental performance in the current condition of Selatpanjang City and analyzes the influence of the urban canyon design models on the thermal environment in the different conditions that is affected conditions by the waterfront building barrier. This is related to the regulation of the Directorate General of Human Settlements [2] on spatial and building planning in waterfront areas (fig 1). Fig. 1. Condition of canyon design of Selatpanjang city II. THEORETICAL REVIEW In urban environments, the microclimate is influenced by urban space design, urban surfaces and the level of anthropogenic activity causing significant increases in air temperature (Ta) and surface temperature (Ts), depending on the city size and local climatic characteristics [3]. One form of urban space design arising from the growth of the city is the formation of canyons. A canyon is a linear space between buildings standing on two sides and the performance of the thermal environment in the canyon is influenced by the aspect ratio of the building height (H) to the road width (W) [4]. There are two characteristic forms of canyon design, namely Regulation of the Selatpanjang City government no. 09 (2015): • Maximum height for linear settlements: 4 floors • Building line: 6 meters Current condition of Selatpanjang City • Building height: 4-6 floors • Not apply building setback line Regulations of the Directorate General of Human Settlements (2000) • Maximum building height: 15 meters • Building orientation must face towards the water Current condition of Selatpanjang City • Building height: 15-20 meters • Building orientation facing away from the water International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 http://www.ijert.org IJERTV7IS070030 (This work is licensed under a Creative Commons Attribution 4.0 International License.) Published by : www.ijert.org Vol. 7 Issue 07, July-2018 98