night ventilation

The climate of Greece is typical Mediterranean with wet, cool winters and hot, dry summers. The temperature range is on average between 5°C to 35°C without many extreme temperatures and weather events. The cool sea breeze on the islands makes summer conditions milder. According to researchers and assessment reports of the United Nations climate change is inevitable in the 21st century. Regional climate models related to Greece show low uncertainties.

Night ventilation has been applied successfully to many passively-cooled or low-energy office buildings. This paper analyses the thermal comfort achievable according to European standard EN 15251:2007 by applying this strategy in office buildings in Spain. Specifically, the comfort level is evaluated using the Degree Hours (DH) criteria and the maximum indoor temperature.

This study presents some results from a monitoring project with night ventilation and earthto- air heat exchanger. Both techniques refer to air-based low-energy cooling. As these technologies are limited to specific boundary conditions (e.g. moderate summer climate, low temperatures during night, or low ground temperatures, respectively), water-based low energy cooling may be preferred in many projects. A comparison of the night-ventilated building with a ground-cooled building shows major differences in both concepts.

An isothermal CFD study was made of a building perpendicular to the wind direction. The building was modelled with a closed façade, and consecutively with one and multiple openings. The sensitivity was investigated for different turbulence models, meshes and near wall treatments, both in 2D and 3D. A large sensitivity was found to the modelling options with regard to the predicted wind pressure coefficients (Cp) distribution, but less with regard to the predicted flow rate through the openings.

This paper discusses the potential of passive cooling techniques for Malaysian modern houses with the aim of reducing air-conditioning usage. A full-scale field experiment was carried out to reveal the detailed indoor thermal environment for various ventilation strategies. Night ventilation was found to be better than daytime ventilation, full-day ventilation and no ventilation in terms of air temperature reductions during the day and night. Night ventilation improves thermal comfort more than the other ventilation conditions based on operative temperature.

Wind catcher systems have been employed in buildings in the Middle East for many centuries and they are known by different names in different parts of the region. Recently there has been an increase in the application of this approach for natural ventilation and passive cooling in the UK and other countries.

Several high schools in the south east of France are subject to a major work of renovation. These works need to take into account the problem of summer comfort for a better well-being and intellectual performance of students. One of it was chosen to carry a study on the specific constraints for achieving summer comfort. The study consists of surveys, monitoring and simulations. This enables to determine the major causes of the summer discomfort in field and to propose several passive solutions. These solutions were assessed by simulation using a dynamic simulation tool.

In this article the concept of a new energy-efficient office building and results of a 3-year monitoringare described. The monitoring was performed within the German funding programme ENOB.In this building most of the offices are naturally ventilated and passively cooled. Another focus of theenergy concept is on regenerative heating.Monitoring results show that the integrated planning enabled a very low consumption of energy forheating, ventilation, cooling and lighting.

The paper presents the effects of airflow access points on the passive modification of indoor air temperature in a partly roofed high-mass courtyard building found in moderate climate of southeast Queensland. Results of a field investigation reveal that despite sufficient shading within the courtyard, its air temperature and thus comfort levels depend greatly on the location of airflow access points in the building layout and section.