Modeling contaminant exposure and indoor air quality in a single-family house.

In this study, computational fluid dynamics (CFD) and a variety of mixing models is used to evaluate the indoor air quality in a small single-family house. CO2, CO, NO2, formaldehyde (HCHO), and vapor are tracked throughout the house to determine the concentration levels, occupational dosing, and personal exposure for a family of two adults and two children. Variations in metabolic activity, smoking, gas stove cooking, and showering make exposure very dependent on the individual's location in the house due to pollutant migration.

Design of ventilation systems in industrial buildings. A computational approach of displacement ventilation in paper industry.

In this paper, the ventilation of a “crêpe” paper-processing workshop containing dryers, which generate a high thermal load, is considered. Displacement ventilation has been used for many years in industries with high thermal load. The main ventilation de

Integration of indoor and outdoor airflow study for natural ventilation design using CFD.

Natural ventilation is one of the most fundamental techniques to reduce energy usage inbuildings. However, due to complicated site plans and building layouts, it is difficult todesign optimal layouts for the enhancement of ventilation without knowledge about the flowpatterns. The employment of computational fluid dynamic (CFD) tools in the design processcan give predictive feedback to the designers, allowing them to optimize airflow around thesite to decide on building placement, orientation, and interior space layout.

"Humid Air" and cooled walls.

The humidity of room air is a necessary influence of design under the aspects of thermalbehavior, technology and conservation.The moisture absorption in the walls through sorptive materials or dehumidification on thecold window surface by dew point condensation is low because of the new thermalcharacteristics of these components.The moisture load of a room briefly or also continuously, caused by technological processesor the users cant be compensated.Today, the walls are used like a floor heating system.

Validation of a computational fluid dynamics simulation of a supply air 'ventilated' window.

A currently unresolved problem in building design is the paradox between increasing demandfor good thermal insulation, and the requirement for ample levels of ventilation, to maintain ahealthy indoor environment. A possible solution to this problem is a supply air ventilatedwindow. This utilises an airflow between panes to pre-heat ventilation air to the building, andto reduce thermal convection losses thus reducing the window U-Value. At the base of thewindow is a vent to the external environment, allowing air inflow.

Significant limitations in applying computational fluid dynamics (CFD) to predict room air distribution: guidelines for beginners.

Computational Fluid Dynamics (CFD) has been used to predict the indoor environment airflow and overall ventilation effectiveness of natural or mechanical air distribution systems. This paper highlights some applications and criticism work made on CFD in order to establish an understanding of the limitations of CFD in predicting room airflow. It is concluded that though CFD is a powerful tool for simulation, the software complexities, computational power and the level of expertise that CFD codes require shape the greatest challenges to beginners in this field.

Effect of control strategies on ventilation system performance.

Dynamic computer simulations were used to compare residential ventilation methods to identifyan approach that would improve indoor air quality with minimum energy penalty while maintainingcomfort.

On ventilation needs - towards demand controlled ventilation in dwellings.

Ventilation needs in dwellings must be determined on the basis of both requirements to theindoor air quality and necessary control of moisture conditions. As a first step towardsdevelopment of energy efficient ventilation strategies for demand controlled ventilation infuture dwellings theoretical analyses comprising a literature study and mathematicalsimulations have been carried out.

Performance of demand controlled ventilation: case study, energy savings and practical rules.

In order to assess the real performances of different demand controlled ventilation (DCV)systems, two of them were installed in meeting rooms of an office building.The first system is controlled by movement detection on terminal units and has been installedin a small meeting room which is regularly used.The second system is controlled by CO2 detection and frequency variation on fan. It has beeninstalled in a large meeting room (30 persons seated, up to 50 persons standing).The systems have proved to be energy saving with correct CO2 levels.

Demand controlled ventilation in schools - energetic and hygienic aspects

In this study, we investigated the indoor air quality (IAQ) in classrooms with exhaustventilation systems and in naturally ventilated classrooms. In the latter, we found peak CO2-concentrations of more than 4000 ppm. 1500 ppm was exceeded during 40 to 86% ofteaching time, dependent on class size. The windows were opened rarely in winter which ledto low mean air exchange rates of 0.20 0.23 h^-1. The operation of mechanical ventilationsystems improved IAQ considerably. Peak CO2-concentrations decreased to less than 2500ppm. 1500 ppm was exceeded for only 7 to 57% of teaching time.

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