Evaluation of indoor air quality using the decibel concept based on carbon dioxide and TVOC

Abstract Two new units are proposed for the evaluation of indoor air quality using the decibel concept, which give a much better approximation of the human perception of odour intensity, compared to the CO2 and TVOC concentration scales: the decicarbdiox and the decitvoc. On the Psycho-Physical Scale according to Yaglou, the weakest odour that can be detected by the human smell sensors is equal to 1 and corresponds to the lower limit of percentage dissatisfaction (PD) of 5.8% and is equivalent to (a) a CO2 threshold concentration of 485 ppm — O dB (odour CO2) — dCd (decicarbdiox), and (b) a TVOC threshold concentration of 50 μg/m3 — O dB (odour TVOC) — O dTv (decitvoc). The upper limit is determined by the initial value of toxicity (a) CO2 — 15,000 ppm — 134 dCd, and (b) TVOC — 25,000 μg/m3 — 135 dTv. It is supposed that optimal values corresponding to PD=20%, admissible values to PD=30% for unadapted and adapted persons and that long-term tolerable values (determining SBS range) and short-term tolerable values (beginning of toxic range) are stated as well. The same figures used to evaluate noise can be used to evaluate air quality, additionally the contribution of individual constituents (at present acoustic and odour) to the overall quality of the environment can be ascertained. The new units dCd and dTv can express an increase or decrease in air contamination, i.e. by using air cleaners, new building materials, etc. The proposed system of dCd and dTv is compatible with BSR/ASHRAE 62-1989 R which can be used to determine the required volume of fresh air for ventilation by an improved method which takes into account different levels of required indoor air quality.

[1]  F. H. Rohles,et al.  Indoor environment acceptability: the development of a rating scale , 1989 .

[2]  John A. Hoskins,et al.  Current Levels of Air Contaminants in Indoor Air in Europe: A Review of Real Situations , 1993 .

[3]  Frank B. Murray,et al.  Control and Regulation of Indoor Air: An Australian Perspective , 1993 .

[4]  J. Wal,et al.  Indoor Air Quality in Renovated Dutch Homes , 1991 .

[5]  Derrick Crump,et al.  Sources and Concentrations of Formaldehyde and Other Volatile Organic Compounds in the Indoor Air of Four Newly Built Unoccupied Test Houses , 1997 .

[6]  B. Seifert,et al.  Regulating Indoor Air , 1992 .

[7]  Markku Rajala,et al.  Indoor air quality and ventilation , 1982 .

[8]  N. A. Oseland,et al.  Perceived air quality: Discussion on the new units , 1993 .

[9]  Nick Parine.  The Use of Odour in Setting Ventilation Rates , 1994 .

[10]  Birgitta Berglund,et al.  The influence of ventilation on indoor/outdoor air contaminants in an office building , 1982 .

[11]  Jorma Keskinen,et al.  Continuous monitoring of air impurities in dwellings , 1989 .

[12]  Jokl Mv,et al.  Evaluation of indoor air quality using the decibel concept. Part II-ventilation for acceptable indoor air quality. , 1997 .

[13]  M. V. Jokl,et al.  New Approaches for the Determination of Ventilation Rates: The Role of Sensory Perception , 1993 .

[14]  V. Bencko.  Health Risk of Indoor Air Pollutants: A Central European Perspective , 1994 .

[15]  O. Valbjørn,et al.  The “sick” building syndrome in the office environment: The Danish town hall study , 1987 .

[16]  M V Jokl,et al.  Evaluation of indoor air quality using the decibel concept. Part II-ventilation for acceptable indoor air quality. , 1997, Central European journal of public health.

[17]  L. Mølhave,et al.  Volatile Organic Compounds, Indoor Air Quality and Health , 1991 .

[18]  M. Jokl.  Evaluation of indoor air quality using the decibel concept. Part I--proposal of new units. , 1997, Central European journal of public health.

[19]  P. Fanger.  Introduction of the olf and the decipol units to quantify air pollution perceived by humans indoors and outdoors , 1988 .

[20]  M. D. Hersey,et al.  Introduction to the theory of similarity , 1965 .