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.
Material properties, water vapor permeability, sorption/suction isotherm and moisture diffusivity, are prerequisite for application of all hygrothermal models. Based on the experimental results and well-determined material properties, a numerical model was validated. This model was then used to analyze the sensitivities of the moisture flow across imperfect hydraulic contact interface with respect to these three material properties.
The mitigation to reduce indoor pollutant concentration are increasing ventilation rate or to reduce the emission of the pollutant which is also common in VOCs. Households, furnitures, building materials and so are well known as the source of indoor VOCs. There are several devices to measure emission of VOCs, such as an emission chamber or FLEC, which are adopted in ISO 16000. However these 2 methods has each disadvantages e.g. the chamber is suitable only in a fixed condition such as a laboratory, or the necessity of a pump and humidifer.
The use of hypochlorite for water disinfection is source of chloramines production, which are transferred to the atmosphere.Nitrogen trichloride (NCl3) is the main component, which is a major cause of respiratory and ocular problems for swimmers and lifeguards. This first part comprised a sampling campaign concerning the measurement of NCl3 in a swimming pool (Picardie-France) during 15 days (October 2001). This campaign concerned the air quality diagnostics and showed that the majority of detected levels were critical (P50 = 0,44 mg/m 3 ).
It is well understood that there are many sick professional buildings in use all over the world. Most of them are sited in or near the center of large cities where the ambient atmospheric conditions are not good. The sickness syndrome of those buildings combines both the indoor air quality and the local comfort regime. In many cases the responsibility for the formation of these syndromes lies with the not appropriate envelope design and the misuse of the building by the inhabitants.
In this work, experiments were carried out to estimate deposition rate of 5µm particles powder in large cylindrical straight ducts for different diameters. Two types of ducts were compared: rigid ducts and flexible ducts. Results are compared to theoretic
Basis of this work was the question of the formation of air flows in ventilated test rooms with regard to wall influences. In order to determine the effects of the room geometry and the air inlet angle a on the airflow a jet which was placed just below the ceiling was observed in symmetrically designed test rooms. Since there is a correspondence between measurement and CFD simulation, velocity vectors are extrapolated from the CFD simulation and analysed for different geometrical data.
Constructional aspects and the use of school building had led to moisture and mold damages confirmed by microbiological analysis from material, surface and air samples. Cultivation methods were used to assess mesophilic fungi and actinobacteria. High concentrations of microbes (10 5 -10 6 cfu/g in different materials) were recovered from the samples. Microbes included great variety of moisture indicating species (e.g. Aspergillus versicolor, Trichoderma, Fusarium, Stachybotrys, Chaetomium, Streptomyces).
The needle heat exchanger (acts as a pre filter EU3) was installed in front of the glass fiber used as a fine filter (EU7) in the supply air chamber. Thus, the temperature of the supply air increased and the relative humidity of the fine filter next to the heating unit decreased. The aim of this study was to examine how the installation of the needle heat exchanger effects on the microbial growth and release in the fine filter. The relative humidity of the fine filter in the supply air unit fell below 70 % during different seasons.
This paper presents an approach to evaluate the sensitivity of a roof design to condensation problems, given the uncertainty to achieve continuity of airtightness in practice. The approach consists of a repeated number of simulations with a 2D heat, air and vapour transfer model to predict the variation in roof moisture performance due to various discontinuities in roof geometry. The set of discontinuities is calibrated by comparing measuring data of roof airtightness to simulation results.