108 A r .a ş • t ı r m a The concept of designing for different levels of indoor air quality is also included in the Scandinavian guideline (SCANVAC, 1 991 ), in the Finnish guideline (FISIAQ, 1995) and in ASHRAE 62-1989R. rate in ASHRAE 62-1 989, ASHRAE 62-1 989R, prE NV 1 752 (European standard proposal, CEN), DiN 1 946 Part 2 (Germany), CIBSE Guide A (UK) and NKB-61 (Nordie guideline) has been presented. Standard Class Required ventilation Us person Ali documents include a prescriptive procedure where the required minimum ventilation rate is listed in tables with values for different types of spaces. AII documents also include an analytical method where the required ventilation rate is calculated based on comfort and health criteria. ASHRAE 621 989R, prENV 1 742, and DiN 1946 include the possibility of designing for different levels of perceived air quality. no 20% 40% 100% smoker smoker smoker smoker perENV 1752 A 10 20 30 30 (96) B 7 14 21 21 C 4 8 12 12 ASHRAE 62-89R Adapted 3 6 17 25 Unadapted 5 8 25 33 ASHRAE 62-89 10 10 10 10 NKB-61 (91) 7 20 20 20 CIBSE-Guides A 8 16 24 43 (new 93) Table 7. Required ventilation per person with and without smoking. *Unadapted (m3/cig) Adapted (m3/cig) The minimum requirements in ASHRAE 62-1989R are based on adapted persons, while ali other documents assume unadapted persons. it is possible, however, to design for unadapted persons in the ASHRAE revision. Non-smokers 160 Smokers 40 *Divide m3 by 02832 to obtain m3 Table 8. Required ventilation per cigarette. Smoking 1 1 O 30 in ali documents, except for the existing ASHRAE Standard 62-1989, it is assumed that there is no smoking taking place. in the case of smoking, an additional amount of outside air must be used to obtain acceptable perceived indoor air quality. Table 8 shows the required amount of ventilation air per person when smoking is taking place. The values in ASHRAE 62-1989R are calculated based on a given amount of air per cigarette (Table 9), a normal smoking rate of 1 .1 cigarettes per hour, and 3 cigarettes per hour in smoking lounges (100 % smoking). in DiN 1946, an amount of 5.6 l/s per person must be added to the values in Table 4 independent of the amount of smoking. in the U.S., 25 % of the population smokes, and the average rate is 1 . 1 cigarettes per hour. in many buildings in the U.S., however, smoking is restricted to dedicated spaces. in Table 6, the inftuence of smoking is shown in a landscaped officeand in a conference room. Again, thevaluesforASHRAE 62-1989R are based on adapted persons. The adaptation to tobacco smoke, however, is less than to body odor. The values from the ASHRAE documents are again the lowest and correspond approximately to Class C in the CEN proposal. However, if the space is designed for unadapted persons, the values correspond to Class B in CEN. Conclusions A comparioon between the required levels of ventilation Note: Divide 1/s by. 47,9 to obtain f/min(cfm). DMde m3 by 02832 to obtain ft3 AII of the standards take ventilation effectiveness into account. The lowest minimum outdoor air requirements are found in ASHRAE 62-1989R. References -ASHRAE Standard 62-1989, "Ventilation for Acceptable lndoor Air Quality''. -ASHRAE Public Review Draft 62-1 989R, "Ventilation forAcceptable lndoor Air Quality" . - CEN prE NV 1 752, 1 996, "Ventilation for Buildings: Design Criteria forthe lndoor Environment". -CIBSE Guide A, revision section 2, 1993, "Environmental Criteria for Design, "Charter lnstitute of Building Service Engineers, UK. -DiN 1946 Part 2, 1994, "Ventilation and Air Conditioning: Technical Health Requirements. - FISIAQ, 1995, "Classification of lndoor Climate, Construction, and Finishing Materials, "Finnish Society of lndoor Air Quality and Climate. - NKB Report no. 61, 1991, "lndoor Climate -Air Quality''. Nordic Committee on Building Regulations NKB. - SCANVAC, 1991, "Classifıed lndoor Climate Systems. Guidelines and Specifications". -The Federation of the Scandinavian HVAC Organizations. Table 1 . ScopeforASHRAE62-1989R, prENV1 752, DiN 1 946, Part 2. and CIBSE Guide A. -� ' 1- L 1 1 1 1
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