Ultraviolet germicidal irradiation (UVGI) uses UVC radiation produced by low pressure Hg vapor lampsto control biological air contaminants. Lamp UV output depends on multiple factors, includingaccumulated operating time (age) and the thermal effects of ambient air temperature and velocity.Additionally, the life of some lamp types depends on the frequency of on-off cycles.
Working with volatile chemicals creates numerous hazards for scientists in laboratory. Therefore, it isrestricted to do such works in a fume hood, which is designed to draw fresh air from the room into thehood and then out into the ventilation system, in order to prevent the accidents happened.According to the laboratory fire incidents investigation, the authors observed that a fire occurred infume hood will be a serious problem which has the potential to get much worse in the future as moreand complex laboratories are used and as the hood usage density increase.
This study compared the concentrations of indoor air pollutants identified from the 5 restaurantsincluding a category A (two Korean barbecue houses) during a lunch time period and a category B(one Japanese, one Chinese, and one Italian restaurants) during a dinner time period.
It is of significant importance that heat, humidity and air contents are well balanced in buildings, as animbalance of these factors may have a decisive effect on the construction as well as on the residents, forexample damage to the building structure, decrease of thermal comfort and increase of energyconsumption. Relative humidity, generated within the construction or in the interior of a building, is ofspecial importance. In recent times there is an increase in discussion and investigation on the influenceof humidity absorbing or desorbing surface layers in rooms.
Succeeding to the experimental investigations in the two test rooms at FhG the results provide for acommon exercise in context of the IEA-Annex 41 project to validate several simulation tools. Theintention of this common exercise is to simulate two real test rooms which are located at the outdoortesting site of the Fraunhofer-Institute of building physics in Holzkirchen. During the winter time testswere carried out with the aim to compare the measurements with the models developed within theIEA-Annex 41 project. As moisture buffering material served gypsum boards.
The increasing incidence of airborne transmitted diseases indoors has prompted the attention ofstudying expiratory droplet dispersion and transport in built environments. Droplet dispersion in aroom under the conventional well-mixed and displacement ventilation is simulated. In this work, asource (i.e. a patient) and a receptor (i.e the susceptible object) were located in a mechanicalventilated room. This study evaluated droplet dispersion and mixing under well-mixing anddisplacement ventilation scheme.
Natural ventilation is a commonly used principle when ventilation systems for buildings are designed.The ventilation can either be obtained by automatically controlled openings in the building envelope, orit can just be the simple action of opening a door or a window to let the fresh air in.
Relative humidity is one of the most important parameters which have an influence on human comfortand indoor air quality. Materials exposed to the air can absorb and desorb moisture and thereforeinfluence the relative humidity level. However hygroscopic materials are not always taken into accountin building energy performance simulation codes. The objective of presented work was to improvepredictions of the indoor relative humidity in a well known energy simulation tool TRNSYS.
In this paper air distribution solutions aiming to lower air velocities and good temperature control arestudied by measurements in 6 schools and temperature simulations. Air velocity measurementsshowed good performance of duct and ceiling diffusers which provided maximum velocities less than0.2 m/s and can be highly recommended for classrooms. The wall diffusers were clearly not suitable forclassrooms due to high velocities up to 0.43 m/s.
This paper is concerned with a building situated in the west of Scotland which faces severe weatherconditions with high wind speeds and driving rain occurring frequently. This results in extensivedamage to the building fabric, and affects the internal climate which leads to a serious issue in buildingconstruction. In this study, a three-dimensional numerical model of airflow around the building isinvestigated. This investigation is part of ongoing research on wind-driven rain which has establishedthe importance of moisture stresses, wind flow and rain impacts on a commercial building.
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