An experiment was carried out to determine the effect of photocatalytic air cleaning on perceivedair quality. Thirty-eight subjects assessed the air quality in a low-polluting, 108 m3 office, with pollution sources either present or absent behind a partition. The pollution sources were carpet, linoleum and chipboard. The office was ventilated with outdoor air at 0.6, 2.5, and 6 h-1. The air temperature was 22C and the relative humidity 40%.

The paper reports on findings from a series of experiments where the supply flow rate wasvaried periodically in time. All experiments were conducted in a small scale model with water as operating fluid. The flow was visualised by adding particles to the water and the streaks were recorded with a digital camera. The main result is that there exist variations that generate a role up of the base flow by generation of vortices that are shed into the stagnant region.

The perceived intensity is investigated by a trained group of 10 to 15 persons. Until now fieldstudies have to be made at the location of interest. All members of a trained group have to visit e.g. a building in order to estimate the perceived intensity of the indoor air. The trained group is influenced by the local environment. This paper presents a new method to sample and to store air probes at arbitrary locations. The air probes can then be transported to the laboratory where a standard group test can be made in the neutral and clean environment of an air quality lab.

Electrostatic air cleaners (precipitators) were tested in four classrooms during ordinarylessons for four weeks. Airborne dust in the classrooms was collected on filters using two different kinds of samplers: IOM-sampler and a new kind of ionizing sampler. The amount of collected dust was evaluated by visual inspection (filter blackening) and the content of cat allergen was measured using an amplified ELISA assay. It was found that the filter blackening was 64% lower when the air cleaners were active than when they where inactive (p

Previous work on an Underfloor Air Distribution (UFAD) system with a single heat source anda single cooling diffuser at floor level developed by Lin has been extended to study the effects of the vertical location of the heat source and of multiple cooling diffusers. This is an attempt to produce more realistic models of UFAD systems. Both experimental and theoretical modeling is described in this paper. In the experiments, a plume and fountains represent a heat source and cooling diffusers respectively.

Tracer gas measurements are commonly used to estimate the fresh air exchange rate in a room or building. Published tracer decay methods account for fresh air supply, infiltration, and leaks in ductwork. However, the time delay associated with a ventilation system recirculating tracer back to the room also affects the decay rate. We present an analytical study of tracer gas decay in a well-mixed, mechanically-ventilated room with recirculation.

Amongst various sources of polluting substances the open space gas-range have an impact onthe quality of living spaces. Carbon-dioxide and nitrogen-oxides occurring during burning considerably impair the air quality. Emission of polluting substances has been examined in the Laboratory of Air Quality of Dept. of Building Service. The results of the research supported by the Ministry of Education (T0375 96) will be presented here.

The research was oriented to analyze better the ventilation systems, in terms of cost-to-quality ratio. The matter of the paper is that a ventilation system is designed to work in certain quality conditions, but every quality has its cost. This cost comprises investment, energy consumption and operation-maintenance expenditures.

The paper reviews the effect of environmental parameters on the migration of particulate matter. Themethodology involves simultaneous monitoring of particulate matter using dust monitor at indoor and outdoor locations along with the ambient environmental conditions. The study is of great significance as Particulate Matter (PM) has been reviewed in terms of particle count, which is more significant as compared to particle mass. In this paper, the variation of Indoor (PM) /Outdoor (PM) calculated on the basis of count are studied as a function of ambient wind speed, temperature and humidity.

A recent survey study suggested that elderly people’s lifestyle and building + dwellings factors exposed them to an uncomfortable and poor environment regarding indoor air quality. In order to confirm the qualitative statements of this study, measurements