perceived air quality

The existing standards for testing gas-phase air cleaners are based on challenging them with gaseous substances. They do not describe air quality measurement using perception, and human emissions (bioeffluents) are not used as challenge pollutants. The present work examines the method that can be used as an alternative or together with other methods used for testing gas-phase air cleaners. The work is a part of the IEA's Annex 78. Three gas-phase air cleaners were tested in the Technical University of Denmark labs.

Worldwide, there is an increasing number of publications related to air cleaning and sales of gas phase air cleaning products. This puts a demand for verifying the influence of using air cleaning on indoor air quality, comfort, well-being and health. It is thus important to learn whether air cleaning can supplement ventilation with respect to improving air quality i.e. whether it can partly substitute the ventilation rates required by standards.

Occupants in non-industrial indoor environments should decide whether the indoor air quality is acceptable or not. This paper describes the method by which the assessments of acceptability of air quality can be used for measuring short-term sensory effects on humans caused by indoor exposures. It also describes how this method can be applied to estimate the perceived indoor air quality used as a design criteria for the ventilation of buildings.

Carbon dioxide (CO2) has traditionally been assumed innocuous at the typical levels indoors, and merely an indicator of metabolic emissions from humans (bioeffluents). Recent studies suggest that exposure to pure CO2 at concentrations of 2,500 to 4,000 ppm, the levels that occur periodically indoors, can have negative effects on mental performance in form of reduced ability for making decisions, typing and proofreading. Present study aimed to examine further these effects. Twenty-five human subjects were exposed to elevated CO2 with and without bioeffluents in a chamber.

The main objective of the ongoing research project described in this paper was to study the potential forreducing energy used for ventilating buildings by using low-polluting building materials, withoutcompromising the indoor air quality. To quantify this potential, the exposure-response relationships, i.e.the relationships between ventilation rate and perceived indoor air quality, were established for roomsfurnished with different categories of polluting materials and the simulations of energy used forventilation were carried out.

The objective of this study was to test a new office space where the environmental conditions could be well controlled- a "field laboratory", located at Mid Sweden University in 6stersund. To test the laboratory, the same experiment that had been carried out earlier at the Technical University of Denmark (DTU) was repeated. A further objective was to test whether the earlier results from DTU showing a negative impact of increased indoor air pollution on perceived air quality, Sick Building Syndrome (SBS) symptoms and performance could be repeated.

Perceived air quality, Sick Building Syndrome (SBS) symptoms and productivity were studied in an existing office in which the air pollution level could be modified by introducing or removing a pollution source. This reversible intervention allowed the space to be classified as either non-low-polluting or low-polluting, as specified in the new European design criteria ·for the indoor environment CEN CR 1752 (1998). The pollution source was a 20-year-old used carpet which was introduced on a rack behind a screen so that it was invisible to the occupants.

Surveys in several office buildings have shown that crowded work places, job dissatisfaction and physical environment are the main factors affecting productivity. the data was produced and analyzed using occupational stress indicator in conjunction with the analytical hierarchical process. thermal problems, stuffiness, sick building syndrome factors and crowded work places were most frequent complaints. the results suggest that the productivity could be improved by 4 to 10% by improving the office environmental conditions.