The work of Task Force IX started in 1997 at a workshop in Washington Healthy Buildings conference. It continued at the Indoor Air ‘99 conference in Edinburgh, Scotland, and the following workshops took place at Healthy Buildings ‘00 in Helsinki, Finland
In practice, the commonly used Dutch design criterion for long-term thermal comfort inbuildings- the weighted temperature exceeding hours method- often leads to confusion.The criterion is hard to understand for non-experts, and many doubt the validity of thepresent criterion: how sure are we that meeting the requirements really means that futureoccupants will be comfortable?
Microbial growth has been known as one of the major problems related to IAQ inresidential and commercial buildings. International and local standards define theupper limits of indoor relative humidity in order to avoid moisture related problems.However, setting limits on indoor relative humidity does not guarantee a mould-freeenvironment.
Thermal and moisture performances of whole buildings are rather well understood today andvarious models exist for simulating those. However, models for calculating VOC emissionsfrom or through building envelope parts are still rare and often need specific materialproperties for each transported compound.
This study reports the attained indoor air quality in new buildings when using different M1-classified finishing materials and ventilation systems. It is practical to use the TVOC value asa reference in comparing material emissions, their effect on indoor air quality and infollowing the effect of different parameters on the indoor air quality. But is TVOC a relevanttool from the health point of view to be used in characterizing the indoor air as the singlecompounds contained in the TVOC value do have very different effects on the health andperceived indoor air quality?
In recent years, the World Health Organization has published a database with detailedestimates of the global burden of death and morbidity by disease, age, sex, and region. Justthis year, a WHO-organized international team expanded this effort by systematicallyestimating the individual burdens for some two dozen more distal risk factors by age, sex,and region, including, inter alia, malnutrition, hypertension, tobacco use, obesity, unsafesex, and several environmental and occupational risk factors.
The activities of indoor environmental research have increased significantly since the firstenergy crisis of the early 1970s. Since then, research has produced many significant resultsthat have already been put into practice. These include the health effects and prevention ofenvironmental pollution by tobacco smoke, formaldehyde, radon, asbestos, etc. The healthrisks of these contaminants have been verified, and appropriate measures have been taken bythe authorities, as well as by the building industry and product manufacturers.
This investigation uses three subgrid-scale models of large eddy simulation (LES) to study airflows in and around buildings. They are the Smagorinsky model, a filtered dynamic subgrid-scale model, and a stimulated small-scale subgridscale model. For outdoor airflow that is highly turbulent, the simple Smagorinsky model is sufficient. For indoor airflow where laminar flow can be as important as turbulent flow, the filtered dynamic subgrid-scale model and the stimulated small-scale subgrid-scale model are recommended.
Theoretically if the thermal properties of a building envelope and the power of the HVAC systems are known, then air infiltration becomes the only one unknown component of the thermal balance of a building and could be defined from it. In reality, all data are approximate. Modern measurements and data processing techniques allow one to evade this obstacle.