IJV13

As natural wind is continuously fluctuating in both speed and direction, quantifying instantaneous wind-driven natural ventilation rate can be difficult, and often an average effect is used to stabilize the fluctuations. This work performs an experimental investigation to assess the validity of assumptions often used in quantifying airflows through an opening under cross natural ventilation condition. In the experiment, the three velocity components are analyzed for flows approaching and through an open window exposed to natural wind.

Air quality in a classroom is very important. According to a study by Wargocki et al (2012) a shortage of ventilation in the classroom reduces the ability of students to concentrate and causes an increase in the number of errors during the elaboration of tasks. The aim of this study was to contribute to the optimization of acquisition and operating costs of HVAC equipment and to ensure hygienic requirements of air quality in the indoor environment for classrooms.

Air change rate is often used as an important characteristic of indoor environmental quality, which significantly impacts human health. However, easy, effective, real-time and low-cost air change rate measurements in naturally ventilated resident buildings are still a huge challenge. This paper presents a method based on the release of a stable rate of the tracer gas CO2 given off by solid CO2 (dry ice) in an insulated box.  In theory, the dry ice will sublime at a constant rate as long as there is sufficient dry ice in the box.

In typical Chinese commercial kitchens, the large amount of heat and moisture that is generated must be removed. The ventilation and energy consumption rates can be huge. Middle and small scale commercial kitchens in China produce an exhaust airflow rate so large that without a reasonably effective ventilation system, the temperature and contaminant concentrations are far more than acceptable levels. To fulfil all the requirements of indoor air conditioning in an economical manner, a new air distribution pattern called air curtain ventilation (ACV) is presented in this study.

This paper reports an investigation into the ability of the air supply in non-unidirectional cleanrooms to aid recovery from episodes of airborne contamination, and minimise airborne contamination at important locations. The ISO 14644-3 (2005) recovery test, which measures the rate of decay of test particles, was assessed and a reinterpretation of the test results suggested. This allowed air change effectiveness indices to be calculated and used to evaluate the ventilation effectiveness of the cleanroom’s air supply.

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

The thermal comfort of the “Home for Life” dwelling in Denmark, the “LichtAktiv Haus” in Germany and “Sunlighthouse” in Austria is investigated with a particular focus on the control strategies and the role of solar shading and natural ventilation (ventilative cooling). These houses are three of six buildings in the Model Home 2020 project (Feifer, 2013). They have generous daylight conditions, and are designed to be energy efficient and CO2 neutral with a good indoor environment.

According to researchers, climate change is inevitable in the 21st century. As far as Greece is concerned, this climate change will be related to an increase in ambient surface temperature and to a decrease in annual precipitation. On the other hand wind patterns will not change significantly. Also, no significant changes are expected for global solar radiation. Regional climate models related to Greece show low uncertainties. The climate of Greece is typical Mediterranean with wet, cool winters and hot, dry summers.

Non-invasive, scalable, building retrofit solutions are very attractive deep renovation techniques to improve energy efficiency in existing buildings; this includes natural ventilation for cooling due to the low impact nature of the installation. However, a number of criteria that are important to natural ventilative cooling strategies can be substantially altered as a result of an external retrofit solution.

The indoor environmental quality and health of occupants in approximately 5000 dwellings were investigated by questionnaire covering the whole of Japan. The purpose of this survey was to clarify the association between indoor air quality and adverse health effects and to study effective ways of keeping indoor air clean using mechanical ventilation. Questionnaires were distributed to 7812 occupants living in mechanically ventilated houses across 47 Prefectures in Japan in February 2012 of which 5265 occupants replied.