Masayuki Oguro

Cooling effects of a river and sea breeze on the thermal environment in a built-up area

Abstract Two kinds of field observation are carried out to examine the cooling effects of a river and a sea breeze on the thermal environment in a built-up area in summer. One is the measurements along a river and an avenue which go in the direction of the sea-land breeze. The other is the measurements along a street nearly perpendicular to the river. The wind speed above the river is larger than that above the street when the sea breeze blows, while the air temperature above the river is clearly lower than that above the avenue. The air temperature difference between them falls less downstream of the sea breeze. The air temperature in the space between buildings is the highest in the street and that at the cross point is the next; the wind direction is close to that of the sea breeze. Even if the paths are rather narrow, the ventilation effect by the sea breeze is clearly recognized.

Development of Low Carbon Districts Simulator

We developed an HVAC energy consumption simulation system for analyzing annual hourly transitions in the solar radiation environment. Since the solar environment is influenced by the configuration of buildings in a city block, the reflections between buildings, and the influence of roadside shade trees, it is important to understand the environment of the city block when planning building projects. We developed an annual solar radiation simulation method that uses a radiation balance analysis output database and standard climate data. The method reduces to 1/30th or less the number of analyses necessary to predict the annual hourly solar environment distribution as compared to the number required by the general method.

DEVELOPMENT OF WIND ENVIRONMENT DATA-BASE FOR COMPREHENSIVE ASSESSMENT SYSTEM FOR BUILDING ENVIRONMENTAL EFFICIENCY ON HEAT ISLAND RELAXATION

A new assessment system named CASBEE-HI (Comprehensive Assessment System for Building Environmental Efficiency on Heat Island Relaxation) has been developed for evaluating the effects of various countermeasures related to building design on heat island relaxation. In CASBEE-HI, environmental efficiency concerning the heat island relaxation (BEEHI) is defined as QHI/LHI, where QHI is the quality of outdoor thermal environment within a building site and LHI is the loadings emitted from this building site to increase the heat island effects in its surroundings. To assist the evaluator to examine the wind environment, two different scale wind environment databases were developed. In the present paper, wind environment databases for Tokyo and Osaka are described. The present Tokyo database includes results of three-dimensional CFD analysis in which all the existing buildings in the special 23 wards of Tokyo are reproduced in three-dimensional geometries in a grid network of approximately 500,000,000 meshes with a spatial resolution of 8 m in the horizontal directions.