passive cooling

Passive cooling in the built environment is now reaching is phase of maturity.  Passive cooling is achieved by the use of techniques for solar and heat control, heat amortization and heat dissipation. Modulation of heat gain deals with the thermal storage capacity of the building structure, while heat dissipation techniques deal with the potential for disposal of excess heat of the building to an environmental sink of lower temperature, like the ground, water, and ambient air or sky.

Natural ventilation is increasingly considered a promising solution to improve thermal comfort in buildings, including schools. However in order to support its planning and implementation, quantitative analysis on airflow paths and heat-airflow building interactions are needed. This requires an adequate accounting of both internal effects, from building layout and structure, and external forcings from atmospheric factors.

The monitoring of a demand controlled heat recovery ventilation system with ground heat exchange in a zero-energy building in Groenlo, The Netherlands, revealed interesting practical insights.

It is still difficult to confirm from available data if global warming and climate changes have played a role in increasing heat-related injuries. However, it is certain that global warming can increase the frequency and intensity of heat waves, which can cause discomfort to the human body and, in the worst case, can lead to more heat illness casualties. Recent worldwide natural disasters, such as the Tohoku earthquake in Japan, flooding in Thailand, and the Pakistan heat wave show that climate change is truly a fact.

A double skin façade (DSF) aims at reducing heating and cooling loads by taking advantage of daylight and utilizing heated air for space heating. To take advantage of a DSF a sophisticated design is required. In this paper a DSF building that has overheating problems was selected to verify the causes and propose remedial solutions. The problem was verified by analyzing the measured solar radiation, inside and outside temperature and air velocity. The results of the measurement analysis showed that airflow congestion caused overheating inside the building.

This paper presents a simplified modelling process by using experimental results to form empirical relationships for a particular novel windcatcher natural ventilation and cooling system developed by Monodraught in the United Kingdom. In particular, the behaviour of this system, which is integrated with a DC fan and PV panel without a backup battery, is modelled for the whole year. The impact of natural and night time ventilation with thermal mass on cooling and mitigating overheating is investigated.

The potential application of Passive and Hybrid Downdraught Cooling to residential buildings is explored using an experimental facility constructed and tested in Seville, Spain. The experiment was devised as a prototype of the downdraught evaporative cooling system for the Nottingham University entry to the 2010 Solar Decathlon Europe competition.

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.

This paper presents a study aimed at evaluating the effectiveness of natural ventilation strategies used in government dwellings in the Egyptian desert climatic design region. Three government housing blocks, built in the New Al-Minya city, were employed as case studies. Autodesk-Ecotect and FloVent CFD software were used to simulate the internal air movement and air temperatures. Theoretical analysis shows that there is considerable cooling potential by natural ventilation, with the thermal comfort potential being improved by up to 52% peak and 33.5% average.