This study investigates the application of night ventilation techniques in ten urban canyons, situated in the extended region of Athens, Greece. In order to determine the impact of the urban environment on the night ventilation performance, the outdoor air temperature and wind profile have been measured inside and outside the experimental canyons.
Describes a three-year EU funded research project into the application of passive downdraught evaporative cooling (PDEC) to non-domestic buildings. This paper specifically discusses the use of computational fluid dynamics (CFD) to model PDEC. Using a hypothetical office building in Seville, Spain, it describes modelling techniques used and applications in an investigation of the building's performance.
Makes a comparison between the effects on thermal performance and energy use of a number of pre-cooling and ventilation strategies, suitable for use to reduce peak power demands in office buildings in moderate temperature regions. Describes how simulations were performed for different building envelope parts, and for two levels of internal heat load. Lists the results as significant reductions of required daytime peak power loads which may be obtained by cooling strategies that contribute to lowering the internal mass temperatures.
The performance of a Ventilated wall component under real weather conditions was tested, during two weather seasons, winter and summer. The component was built in a 1:1 scale, consisting of two equal area parts, a Ventilated wall with and without a radiant barrier. It was installed at the South faade of a PASSYS outdoor Test Cell at CRES. Air openings were located at the bottom and top of each wall component in order to facilitate the air movement through the air gap.
The Coolhouse project is exploring the viability of alternatives to air-conditioning in southern European countries using innovative passive and low energy cooling and ventilating techniques, with an emphasis on ground cooling. The project will demonstrate a variety of passive cooling techniques and the use of ground cooling systems for housing in Crete and Portugal, a nursing home in southern France and a community centre in Italy. The project partners include architects, energy designers, social housing providers and developers, the project will last 48 months.
A major concern of those wishing to limit the energy use in buildings is the growing trend towards installing air-conditioning in new and refurbished buildings. Building design, high thermal loads, and a desire for perceived comfort, contribute to an ever-growing demand for full air-conditioning. Therefore, to counter the impact on building energy use, it is essential that building design and operation is developed to minimise the use of air conditioning systems.
This paper presents a passive design strategy where thermal comfort is achieved by engaging the occupants to define their own comfort condition and vary the quality of the space according to their needs. Two naturally ventilated houses in South Australia designed with this approach were tested and their actual performance documented. The results showed that most of the time the houses were always comfortable without any assistance from active systems.
We made a series of subjective experiments to grasp individual behaviours and thermal sensation of the occupants in as actual environmental conditions as possible by observation using video cameras. The use of video cameras allows us to have the time-series of scenes of the occupants participating in the experiment; it also allows us to avoid disturbing their natural behaviours and sensations.
We describe the potential of using hygroscopic materials that release moisture and latent heat in order to reduce the temperature of building envelopes and, there upon, conduction cooling loads. It is analysed 3 different weathers and a classic Brazilian wall with different values of paint permeance on both external and internal surfaces. The results are presented in terms of temperature, moisture content profiles and heat fluxes, showing how to save energy from the natural movement of moisture.
The results of numerical simulation on the effects of solar chimney for ventilation in the new building of Faculty of International Environmental Engineering Kitakyushu University, Japan are described. The air velocity and pressure within the solar chimney were estimated by simplified methods and CFD calculation and both results agreed quite well. It was found that the air flow rates would depend on the inside wall temperatures and section ratio of solar chimney with the same section area.