AIVC - Air Infiltration and Ventilation Centre

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Health effects of flooding: changes of symptoms, tear film stability and biomarkers in nasal lavage after re-exposure to a damp office building

The aim was to study changes of symptoms and signs in an office exposed to flooding fromheavy rain. All 18 workers participated in medical investigations in January 1998. Thesubjects were first investigated on a Monday in a reference building and then all moved backand were reinvestigated in a damp building after 2 days of exposure.

Validation of questionnaire data with inspections on dampness indications in 390 Swedish dwellings DBH step 2

A questionnaire on e.g. building characteristics including dampness, and allergic symptomsamong children from 8 918 homes was carried out in the year 2000. 18-24 months later, 6professional inspectors visited 390 of the homes and made inspections and measurements.Questionnaire reports on building characteristics, type of ventilation system, and buildingmaterials were in good agreement with observations from the inspectors (K=0.68-0.87). Individualkappa-values for the inspectors varied in the range of 0.33-0.96.

Isolation and identification of filamentous fungi from HVAC system

During the research, air samples were taken by exposure of agar plates and taking smearsamples from the AC equipment. Sampling took place during the autumn because theconcentration of spores at that time reaches its peak.

Building-related microbes before and after the repair of moisture damage

In two school buildings, concentrations of viable fungal spores in air, material and insurface samples were high indicating moisture and mould damages. Microbesincluded numerous moisture indicating species (e.g. Aspergillus versicolor,Trichoderma, Fusarium, Stachybotrys, Chaetomium, Streptomyces). After renovation,the school buildings were thoroughly cleaned. Surfaces still had abundant anddiversiform microflora. After repeated cleaning, abundance and diversity ofmicroflora diminished.

Dampness in dwellings and sick building symptoms among adults: a crosssectional study on 8918 Swedish homes

Moisture-related indicators indoors are, e.g. visible mould and damp spots, condensation onthe inside of window panes, detached floor covering materials, flooding and bad odours. Suchindicators are frequently found and are reported to appear in 25-80% of the buildingsworldwide (Bornehag et al., 2001). Dampness has also been identified as a major risk factorfor, e.g. respiratory symptoms such as asthma, cough and wheezing among both children andadults (Bornehag et al., 2001).

Combined air, heat, moisture and VOC transport in whole buildings

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.

Two strategies for containing moisture migration

For the building team, the design of library, archives and museum facilities brings with it special responsibilities. Archive and conservation facilities require the highest levels of preservation and maintenance of the building environment. Understanding how to maintain and preserve vulnerable materials is a key component to developing a successful design solution.

Dynamic buffer zone - Controlling moisture and heat flow

The building envelope is primarily an environmental separator, which allows indoor spaces to bemaintained at different conditions from the outside environment. Intentional humidification during the heating season is a common practice in cold climates. Moisture escaping from a humidified building due to air leakage through flaws in the air barrier system can negatively affect the durability of the building envelope.

Moisture accumulation in imperfect hydraulic contact building materials

This paper presents the results of a series of specially designed experiments to study moisture transport across bonded or natural contact interfaces between building materials. The results showed that the bonded or natural contact interfaces between aerated concrete and mortar are imperfect hydraulic contact. In addition, all the tested cases were simulated using a numerical model. The results showed that there was good agreement between experimental results and predictions made by the model.

Study on indoor humidity distributions

This study investigates the behavior of vapor in a ventilated room in which vapor is being produced. A test chamber equipped with three types of ventilation ducts and a vessel filled with heated water for evaporation was analyzed both experimentally and numerically. Experimental results showed that temperature and moisture distributions differed depending on the ventilation types. A numerical model of vapor generation from the heated water was introduced to simulate the evaporation.