Tracer gases and its monitoring method were studied in measurement of ventilation rate by use ofconcentration-decay method. Five kinds of gases (sulfur hexafluoride, nitrous oxide, carbon monoxide, carbon dioxide and isobutene) were compared.In this study isobutene was used as law-environmental-loading tracer gas. Its concentration was monitored with a PID (photo-ionizing detector) monitor.To fix the procedures and conditions for measurement of ventilation rate, the performance characteristics of this system were examined.

In this paper, applied the SARS particle thresholds, the distribution of SARS virus particles in rooms with three different ventilation types and two different virus source locations are compared. And the SARS particle concentration near the sickroom is simulated numerically with two different positions of the exhaust chimney.The conclusions that have been drawn can be used to design the ventilation system of the SARS sickroom for protection.

This paper investigates the feasibility of reducing the outdoor air ventilation requirements by selectinglow-emission materials, while still maintaining acceptable IAQ, for a residential building. The method used was to apply tools such as a computerized database of material emissions and its accompanying IAQ simulation model (MEDB-IAQ).A real two-storey R-2000 house was chosen as the simulation reference case to serve as the basis for comparisons with alternative material selections.

In Korea, almost all flats have the structure of concrete that is cast in forms and ties are used tofix forms. Tie holes are usually filled with cement mortar. Instead of filling the holes in the balcony, they might be used as trickle ventilators. If they do not satisfy completely the ventilation requirement, other ventilators will be needed. The objective of this study is to assess the ventilation performance of these natural ventilators.

Increasing ventilation rates do not always improve IAQ, but proper ventilation strategies are the keys to improve it. This paper discusses the impacts of ventilation on IAQ and some ventilation strategies to improve IAQ are proposed : the low-temperature air supply system, DCV (demand control ventilation) system, TSV (task supply ventilation) system.

Experiments were conducted in the mockup of a Boeing aircraft cabin section located in the BESS(Bioenvironmental Engineering Structure Systems) lab at the University of Illinois at Urbana-Champaign. The objectives of this experiment study included characterizing air distribution using VPTV (velometric particle tracking velocimetry) technique and determining local mean age of air in the ventilated airspaces and ventilation effectiveness using a tracer gas method to evaluate the performance of ventilation systems in removing airborne pollutants.

The paper explores whether replacing old windows, in a significant proportion of UK dwellings, could reduce air change rates below recommended levels unless additional controllable ventilation is installed at the same time as new windows.For that study, the authors have identified a sample of dwellings that were to have complete window replacement, then carried out fan pressurisation measurements before and after replacement in order to assess the impact on the UK building stock as a whole.

The present study determines the particle decay and deposition rates under natural, forced ventilation and no ventilation conditions. It is the first attempt to apply this deternmination to the ventilation conditions existing in Indian urban households.
The study confirms the previous deposition rate observations and most of the values are in the range of the previous reported values.

For that study, IAQ was measured and evaluated in seven representative hotels in Beijing. The evaluated places included the hall, restaurant and guest room.There were different pollutionlevels in different hotels due to differences in sources, location, human activities and ventilation, etc. Within the same hotel, different areas had different IAQ. This study is based on measurement data and associated with domestic and overseas related standards, but it needs further validation and improvement

A new zoning approach is developed in this paper. The main issue of the new approach is that zoning should be based on the distributions of flow field and the zoning results should indicate the uniformity of zones in space.In this work, air age is adopted as a basis for zoning in mechanically ventilated rooms. For the demonstration of the applicability of that new approach for predicting indoor temperature in a displacement ventilated room, a case study is performed. Comparisons of the results with those of a CFD model are presented.