PR2011

This study documented that houses in the southeastern United States built on typical wall-vented crawl spaces possess the following characteristics: 1) bulk water, water vapor and associated moisture issues, 2) mold spores, 3) measured holes between the crawl space and living space and 4) measured transmission of mold spores from the crawl space to the living space.

Accidental releases occurring in industrial platforms or during transportation of hazardous materials can entail the dispersion of toxic gas clouds. In case of such an event, the best protection strategy for people is to identify a shelter in a nearby building and stay in this room until the toxic cloud has finally been swept off.

It has been demonstrated that there is a strong relationship between occupant behaviour and the thermal performance of dwellings. At the same time, some aspects of this behaviour, especially with respect to natural ventilation, constitute some of the most important sources of uncertainty in the field of building energy simulation.

In a great portion of Danish primary schools the mechanical ventilation systems is outdated or simply rely on opening of windows to ventilate the classrooms. This leads to high energy consumption for fans and/or ventilation heat losses and poor indoor environment, as the ventilation systems cannot provide a sufficient ventilation rate. A recent study with 750 Danish classrooms show that 56 % had CO2-concentrations over a 1000 ppm, which is the recommended limit by the Danish working environment authority and this adversely affects the performance and well being of the pupils.

The aim of this study is to check the accuracy of a nodal model to predict correctly the flow fields involved inside a building by wind-induced pressure. The model is confronted to experimental tests involving a one-storey dwelling of 84 m² at a reduced scale of 1/10 placed in a wind tunnel facility. Different configurations are tested considering openings of different sizes for outside openings as well as for internal doors. For each configuration, various wind incidences are studied.

From the beginning of year 2007 the buildings in Finland must have energy efficiency calculations, which requirements are now part of Building Codes, based on European Performance of Buildings Directive. According the renewed code, being into the force from July 2012, air tightness number q50 cannot be more than 4 m3/ (h*m2). Better air tightness can be shown by measurements. The air infiltration must be calculated in compensation calculations based on air tightness number 2.0 m3/ (h*m2). The energy efficiency requirements caused an immediate response in the building sector.

There are often practical limitations to measure the airtightness of a multifamily building as a whole as described in EN 13829. The building may be too large; the floors may not be connected with an internal airflow path; or there may be large leaks in the stairway.

A building was tested the equivalent of over 1,000,000 times under windy conditions where each test satisfied the conditions of ASTM, CGSB, ISO, EN, ATTMA and USACE testing standards in every respect. The air flow measurements made at lower reference pressures, such as 4 and 10 Pa, varied over a wide range of +87% to -45% from the average, while the results at 50 Pa varied 15% from the average.

The air tightness of building has been a serious problem over the last 30 years. In 1979 the international Air Infiltration Centre (AIC) was erected within the International Energy Agency (IEA) platform. Infiltration of cold air into buildings needs to be heated to reach to a comfortable indoor climate. But the energy penalty due to that should be minimized. The AIC (later AIVC) had as one of their tasks to find solutions for good air tight buildings and to promote the knowledge about building construction to reach acceptable level of air tightness of buildings.

In this study, we developed an integrated simulation procedure for prediction of concentration of contaminant exposure using a multi-nesting method connecting building space, a Virtual Manikin, and bronchus airway in humans. On the basis of this numerical simulation, detailed information on the unsteady spacial distribution of contaminant concentration, the breathing concentration of infectious contaminant, and the non-uniform distribution of contaminant deposition in nasal airway could be provided for designers of indoor environments in the design stage and also for residents.