English

Previous studies on single-sided natural ventilation are mostly limited to very simple physical models, such as a single-room or single-storey building. Our recent on-site measurements have shown that previous empirical models based on such simple physical models are inapplicable to multi-storey buildings. In order to explore why, this study systematically compares the ventilation characteristics of single-storey and multi-storey buildings with single-sided natural ventilation.

One of the most commonly used strategies to reduce the heating demand in low energy buildings is reducing the leakage level of the building envelope. Dedicated ventilation systems are then installed to compensate for the reduced air change rate in an energy efficient way. Most occupants, however, operate their ventilation system at very low flow rates. Together with the emission of bio-effluents, linked to the presence of the occupants, moisture production related to household activities is one of the most important sources of indoor air pollution in dwellings.

Emergency Temporary Housing units consisting of a light-gauge steel brace construction were built following the Great East Japan Earthquake of March 11, 2011 (see Appendix). About 30,000 of these units are still in service following a delay in rehabilitation and reconstruction. The heat bridge portion in this kind of construction causes surface condensation in rooms. In addition, condensation damage on the steel roof surface in the attic space is also relatively large.

Indoor temperature and humidity conditions as well as CO2 and airborne mould concentrations were measured in four manor schools in the Estonian cold climate. Based on these measurements, the influence of the indoor climate on the performance of schoolwork was assessed. The indoor environmental quality in manor schools turned out to be quite poor due to the inadequate performance of ventilation and heating systems. Intermittent stove heating was found to secure the minimum temperature in general but in winter thermal comfort was not always guaranteed.

Stack ventilation systems were installed in German schools constructed around 1900 and are no longer in operation. The aim of this study was to show how reactivating these systems could improve the indoor air quality in classrooms. Ventilation stacks were reactivated in three classrooms in a school while a fourth classroom, which was naturally ventilated via openable windows, served as the reference case. All classrooms were measured for carbon dioxide levels, air temperature and relative humidity.

Occupants spend a significant amount of time indoors where temperature and air quality has an important impact on their comfort, health and work performance. Understanding the role of airflow exchange between spaces is crucial to describe the processes of mixing and transport of substances driven by air motion and therefore essential for evaluating indoor air quality. This work presents the results of field measurements and laboratory experiments designed to characterise door operation and to quantify its influence on air volumes exchanged between rooms due to door motion.

Door operation and the subsequent passage of occupants through the doorway can cause containment failures in hospital isolation rooms. Typically hinged doors are used between the isolation room and anteroom/corridor in healthcare facilities. However, sliding doors can reduce door induced airflows through the doorway and hence effectively reduce the contaminant outflow during the door operation.

Exposure to air pollution from both outdoor and indoor origins can cause a myriad adverse health effects including cardiovascular and respiratory diseases, lung cancer and mortality. Approximately 3.7 million people worldwide died prematurely due to outdoor air pollution in 2012. As people spend more than 90% of their time indoors, the majority of exposure to outdoor air pollution actually occurs indoors, let alone the persistence of various indoor pollution sources indoors.

This paper investigates thermal sensation in an air conditioned space with and without a water source such as a water pond and small fountain in Thailand. Questionnaires were collected from experiments involving 140 subjects divided into groups of 6-14 people sitting in controlled rooms of sequences of air velocity with and without a water source. Furthermore, another 41 subjects participated in a room with a large picture of a waterfall and were later exposed to a water source.

A literature study is presented on the theories and models dealing with buoyancy-driven ventilation in rooms. The models are categorised into four types according to how the physical process is conceived: column model, fan model, neutral plane model and pressure model. These models are analysed and compared with a reference model. Discrepancies and differences are shown, and the deviations are discussed. It is concluded that a reliable buoyancy model based solely on the fundamental flow equations is desirable.