In laboratory experiments, we investigated the ability of two task/ambient conditioningsystems with air supplied from desk-mounted air outlets to efficiently ventilate the breathingzone of heated manikins seated at desks. In most experiments, the task conditioning systemsprovided 100% outside air while a conventional ventilation system provided additional spacecooling but no outside air. Air change effectiveness (i.e., exhaust air age divided by age of airat the manikins face) was measured.

Based on concerns about indoor air quality and trends towards tighter envelope construction,there has been increasing interest in mechanical ventilation of residential buildings in the UnitedStates. This paper reports on a situation study of indoor air quality, ventilation and energyimpacts of several mechanical ventilation approaches in a single-family residential building Thestudy focuses on a two-story house in the northwestern United States and employs themultizone airflow and contaminant dispersal model CONTAM96.

It is the objective of the present paper to investigate indoor environmental characteristics ofan office building with an underfloor air conditioning system. Thermal conditions in the roomwere monitored including horizontal and vertical temperature distributions, supply andexhaust air temperatures, and globe temperature. Indoor air quality was investigated bymeasuring carbon monoxide, carbon dioxide and airborne particulate. Velocity distributionsaround a floor air terminal, and thermal comfort around a supply air terminal were alsoinvestigated.

During the experiments and under the experimental conditions, displacement ventilation with air outlets close to floor level were found to produce the lowest concentrations of hazardous substances and aerosols in the working areas of kitchen appliances when compared with mixed or displacement ventilation through ceiling outlets. Displacement ventilation with low-induction ceiling outlets achieved better results than mixed ventilation.

The objective of this research is to investigate thermal comfort and air flow distribution insidea test room which is naturally ventilated. The test room is ventilated through adjustablelouvers. The air pressures and velocities across the openings together with indoor airtemperature and mean velocity at four locations and six different levels are measured. Thecollected data are used to predict thermal comfort parameters across the test room. Tests werecarried out over the winter and summer time.

With increasing demand for acceptable indoor environment it is necessary, already in theconstruction phase, to estimate what effect different environmental factors have on theoccupants. Thermal sensation is affected by many factors of the indoor environment.Predictive models are available which describe overall thermal sensation as function of themost important factors. In this work reference environments have been investigated with athermal manikin. The results from these measurements are then compared to CFDpredictions.

There are often tradeoffs among improving IAQ (Indoor Air Quality), maintaining thethermal comfort, and reducing energy consumption for HVAC (Heating, Ventilating, and Air-Conditioning) systems. A prediction model that can simultaneously treat these factors isrequired to realize good design of sustainable buildings. For this paper, a concept of OccupantContaminant Inhalation is used for long-term assessment of IAQ. A long-term evaluationindicator for other factors such as air temperature is also introduced (Occupancy-weightedAccumulated Deviation from thresholds).

Recent years have brought the popularity of methods in which neutral networks are applied. They seem of particular importance while dealing with diagnosing, predicting and estimating. Those methods rely on collected data base, simulation and interpolation in the so-called learning process. There are attempts at neutral network application in building engineering. The paper sums up the initial phase of research on neural applications in the air exchange estimation.

To evaluate the performance of a ventilation system, the local mean age of air has usually been used to estimate how efficiently fresh air is diffused to a desired location. However, this index alone is often not sufficient to assess the local air quality that is also associated with the property of the contaminant source in a ventilated space. Several new indices have been proposed recently, which enable the use of numerical simulation and appear to be appropriate scales for assessing mixing ventilation systems.

The effectiveness of ventilation related to the two primary tasks of ventilation, (I) the supply of fresh air, and (ii) removal of contaminants, is investigated. To allow a quantitative description of ventilation performance, several effectiveness numbers are discussed, and their dependence on air flow characteristics is explained. The effectiveness of displacement ventilation regarding renewal of the internal air population is analysed both experimentally and by means of Computation Fluid Dynamics simulations.