English

Biological contamination has recently become an important issue in the residential indoor environment. In fact, one of the leading causes of allergic diseases is the presence of mold and mites in house dust that accumulates on the floors, near the breathing zone for infants and toddlers. In this research, experimental studies were carried out in order to examine particle removal efficiency in a room with two ventilation systems: a ceiling exhaust system and a slit exhaust system.

Indentifying pollutants that pose a potential hazard indoors is an important first step to reducing risks. We reviewed key published studies reporting measurements of chemical pollutants in residences. Summary results were compiled and used to calculate representative mid-range and upper-bound concentrations relevant to chronic exposures for over 300 pollutants and peak concentrations relevant to acute exposures for a few episodic activity-associated pollutants.

The indoor environment can play a significant role in the transmission and exposure of various contaminants. In some emerging aerial infections, such as influenza virus, tuberculosis virus, and other biological and chemical contaminants, the airborne route of transmission is thought to be important to evaluate exposure health risk.

Large-scale greenhouses are usually adopted to control the indoor climate conditions in agriculture. The envelope of agricultural greenhouses generally consists of a PVC (polyvinyl chloride) sheet, which produces a so-called greenhouse effect and protection from harmful insects. In winter, a supplementary heating device in greenhouses is needed because of the lower outdoor temperature and the non-uniform distribution of indoor temperature.

Stratum ventilation has been proposed to cope for elevated indoor temperature recommended by governments in East Asia. TRNSYS is used for computation of the space cooling load and system energy consumption. A typical Hong Kong office is investigated. Compared with mixing ventilation and displacement ventilation, stratum ventilation derives its energy saving potential largely from the following two factors: a reduced ventilation load and increased coefficients of performance (COP) for chillers.

The energy impact involved between bringing in outdoor air for indoor air pollution reduction and the energy required to condition this air are investigated in this report. Longterm hourly weather data from several European and American locations were analyzed to determine the average conditions of air over the period of record of the data.

The concentration levels of particulate matter (PM), airborne fungi, carbon dioxide as well as temperature and relative humidity were investigated in the indoor and outdoor environment of two schools in Athens, Greece during the period January to May 2011. The overall concentration ranges of the indoor measured pollutants were: PM10: 14.92-166.18 μg/m3, PM2.5: 3.16-31.27 μg/m3, PM1: 0.72-9.01 μg/m3, UFP: 4188-63093 pt/cm3, total airborne fungi: 28-2098 CFU/m3 and CO2: 389-1717 ppm.

The importance of reducing adventitious infiltration in order to save energy is highlighted by the relevant building standards of many countries.  This operational infiltration is often inferred via the measurement of the air leakage rate at a pressure differential of 50 Pascals.  Some building codes, such as the UK’s Standard Assessment Procedure, assume a simple relationship between the air leakage rate and mean infiltration rate during the heating season, the so-called leakage-infiltration ratio, which is scaled to account for the physical and environmental properties of a dwelling.  The

Passive stack ventilation is a key feature of sustainable building design and has particular potential for use in tall, multi-storey buildings. However, natural ventilation flows through multiply connected spaces may not behave as expected. Recirculation of air through occupied parts of the building and bidirectional exchange flows at ventilation outlets may compromise the intended ventilation scheme resulting in an uncomfortable indoor environment.

In Mediterranean regions, characterized by a hot and humid climate during summer, the exposure of facades and the position of opening windows are important parameters to enhance passive cooling in the building using buoyancy-driven airflow. An example is the double skin façade which is directly exposed to solar radiation.