Improvements on passive ventilation: a world wide design tool and architectural mechanisms to ensure comfort in equatorial tropical humid areas.

Passive solar cooling for hot humid areas represents an important field for innovation, if we want to solve comfort needs in spaces (especially housing) designed to reduce economic, technical and health requirements. In urban areas or deep valleys and rain forests, which are common in most of the tropical equatorial countries, external breeze is not frequent and air speeds are too low to produce cooling, using a simple cross ventilation system. Since 1982 the author has developed new designs and constructions using passive solar techniques.

Air flow characteristics through modulated louvered windows.

This study investigated the pressure flow characteristics over a number of fullscale modulated louvered windows (MLW). The various MLW parameters included louver inclination angle (8), depth (L), aperture (d) and the ratio of aperture/depth (d/L%). Airflow models were developed using both power law and quadratic model equations. By examining the coefficient of determination (r2) for both model equations, it was evident that the quadratic model equation suggested the best curves fit.

Use of a wind wing-wall as a device for low-energy passive comfort cooling in a high-rise tower in the warm-humid tropics.

This paper discusses the use of the 'wind wing wall' as a device for the passive low-energy 'comfort cooling' of the occupants in the interior of a tall building. The case study building is a 21-storey, high-rise office tower. the UMNO building designed by Hamzah and Yeang located in Penang, Malaysia which has been designed to be airconditioned, but can also be naturally ventilated if conditions are suitable. The paper describes cfd air flow modelling of the wind effects on the building and the effect on internal temperatures, air movement and ventilation.

How do winds affect buoyancy-driven ventilation in buildings?

This paper examines theoretically the effects of wind on buoyancy-driven ventilation via some new analytical solutions recently developed by the authors. Three air change rate parameters are introduced to characterise respectively the effects of thermal buoyancy, the envelope heat loss and the wind force. The wind can either assist or oppose the airflow. For the first time, it has been found that for opposing winds, there are two stable ventilation flow rates for a given set of wind and thermal parameter, i.e. the natural ventilation flow exhibits hysteresis.

Research and development of a passive solar house with airflow system in brick walls.

Research and development of new-type passive solar houses are the main purpose of this paper. The proposed passive solar houses haven an air circulation system in brick walls combined with passive heating and cooling systems. A prototype model house with a solar collector and Trombe walls was constructed and its thermal performance was measured to evaluate this new system. The efficiency on the real size model house with attached green houses is discussed through thermal performance simulations.

Characterisation of natural convection in a room communicating with the outside environment through a door.

The present paper describes a numerical method for analysing threedimensional natural convection in rooms connected to the outside through large openings. The calculations made use of a Computational Fluid Dynamics (GDF) procedure which solves the three-dimensional equations for the conservation of mass, momentum and thermal energy taking into account the effects of buoyancy, heat sources, thermal radiation heat transfer and air flow turbulence.

Natural cooling in Hispano-Moslem religious architecture: the case study of the Mosque of Cordoba.

The Mosque of Cordoba is the best example of the Islamic religious buildings that survived in Spain. Its typology corresponds to a mosque of a large scale with the common plan of the early Muslim art. This model became an architectural reference for the mosques of Western Islam. The paper presents the results of measurements undertaken to assess the environmental performance of this building.

Effects of the inflow of outdoor air through a breathing wall on thermal insulation properties and indoor climate in winter.

Breathing walls were installed on opposite sides of a scale mock-up model of a housing structure that was situated in an artificial climate test room. We analyzed the thermal insulation capability. heat recovery effect and indoor climate for the inflow of outdoor air across the breathing wall. The rate of heat recovery reached 30% under strong winds of up to 8 mis. Even when the ventilation rate tripled due to the strong wind, the temperature difference in the vertical direction was less than 2 K.

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