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On the Air Flow in Urban Canyons for Ventilation Purposes

The work described in this paper formed part of the European UrbVent project on urban ventilation.Measurements of wind speed, wind direction, and air temperature were made at four different heights, inside a pedestrian street canyon in the centre of Athens, Greece, and at the top of the canyon. In addition, infrared radiation on the canyon faades was measured. Experimental data were collected at intervals of 30 seconds. The dimensions of the canyon were: height/width=2.3, length/height=50/23=2.2 with an orientation of 12 degrees from North.

Roof-Mounted Ventilation Towers – Design Criteria for Enhanced Buoyancy-Driven Ventilation

Ventilation towers are often incorporated into the design of naturally-ventilated buildings. These towers increase the physical height of the building and thereby potentially enhance the buoyancy-induced air velocity. However, acoustic baffles, insect meshes, etc., placed within the towers result in pressure losses that effectively reduce the area of the flow path, thereby restricting the rate of airflow.

Windcatchers in Modern UK Buildings: Experimental Study

Top down natural ventilation systems, usually referred to as ‘windcatchers’, have been used recently in modern non-domestic buildings in the UK. These systems combine inlet and outlet into a single roof mounted terminal, which is split into sections. Literature exists on theoretical, scale modelling and wind tunnel tests to evaluate the performance of the systems; however there is a scarcity of performance in-use tests. This paper presents the results of air exchange rate tests using the tracer gas decay method carried out in three operational buildings with windcatchers.

Comfort and Acoustic Monitoring in a Large Naturally Ventilated Technically Advanced Building

This paper examines the performance of a large new multi storey building which relies exclusively on natural ventilation. The building is designed to provide the main library and associated functions for Coventry University. The research outlines the sophisticated control systems necessary for such a building and provides an analysis of the strategies and techniques required for its implementation. A case study of user satisfaction demonstrates that a large naturally ventilated building can provide a pleasant comfortable environment for occupants.

Designing Thermal Mass in Naturally Ventilated Buildings

According to its location, thermal mass can be approximately classified into two types: external and internal. Internal thermal mass, such as furniture and purpose-built internal concrete partitions, does not expose to ambient temperature directly, while external thermal mass, such as walls and roofs, expose directly to ambient temperature variation. A virtual sphere method for modelling thermal mass is introduced and its application in building thermal mass design is discussed.

THERMAL ENVIRONMENT IN OFFICE ROOM SERVED BY TASK/AMBIENT AIR-CONDITIONING SYSTEM WITH NATURAL VENTILATION

A task/ambient air-conditioning system with natural ventilation was installed in a high-rise office buildingin Osaka, Japan. This paper will report the results of the field measurements of indoor thermalenvironment and natural ventilation opening performances. From the thermal environmental aspect,the office is properly divided into working task zones and a general ambient zone so as to ensureboth occupants comfort and energy savings. Task air-conditioning is for satisfying individual thermalpreferences by using floor outlets.

THERMAL CHARACTERISTICS OF A DOUBLE-GLAZED EXTERNAL WALL SYSTEM WITH ROLL SCREEN IN COOLING SEASON

The double-glazed external wall (double-skin) system is an effective passive technique that candecrease solar heat gain into the building. Detailed information concerning the thermal characteristicsof the double skin is necessary to accomplish a good design for thermal comfort and energy-saving.In this paper, the 3-dimensional thermal characteristics of the double skin that had the openingspartially installed and was partially shaded by the adjacent building were investigated by a fieldmeasurement.

NUMERICAL STUDY ON AIRFLOW AND TEMPERATURE DISTRIBUTION IN AN AIRPORT TERMINAL BUILDING UNDER NATURAL VENTILATION

The summer natural wind environments inside an airport terminal building under two cases aresimulated by the method of computational fluid dynamics (CFD) in this paper. The two cases havedifferent opening areas for glass curtain wall. Case 1 has the opening ratio of 10% while Case 2 has30%. The paper also uses DeST to simulate the annual natural temperature distribution under twokinds of opening ratio in a whole year.

CFD ANALYSIS OF AIRFLOW CHARACTERISTICS IN OFFICE ROOM WITH TASK AIR-CONDITIONING AND NATURAL VENTILATION

The performance of indoor airflow for the office room with the hybrid air-conditioning system has beeninvestigated by means of CFD analysis. The hybrid air-conditioning system is composed of under floorair supply outlets for task zone and the natural ventilation openings for ambient zone. The measureddata (Kotani et al. 2006) at the office room in existence was used as the boundary condition of the flowrate of each natural ventilation opening and task flow outlets for CFD.

BEARING THE SUMMER HEAT IN URBAN OSAKA APARTMENTS: ANALYSIS BY AGE

A questionnaire survey of urban Osaka apartment residents elicited data related to the use of airconditioners, portals, and electric fans as means of bearing summer heat. Those means respectiverelationships to respondents attributes, especially age, were investigated. Results show the following:1) regarding electricity expense awareness, younger respondents (under 40 years old) save electricitymore (p

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