106 A r a ş _. t ı r m a The prescriptive method in ASHRAE 62-1989 R requires a minimum ventilation rate per person and a minimum ventilation rate per square meter floor area. The tvvo ventilation rates are added. The people-related ventilation rate dilutes pollution from a person (odor) and from the person's activity. in ASHRAE 62-1989, the minimum ventilations rate is given only as "per person". in prENV 1 752, a required minimum ventilation rate is given per person and per square meter floor area, and the values are added. it may, however, be assumed that the building is not emitting any pollution. in DiN 1 946, t here is both a minimum required ventilation rate related to the activity of the person. Therefore, different values are assigned in the document for conference rooms (2.5), restaurant kitchens (4.0), reception areas in offices (3.5), malIs (4.0), fitness centers (1 2) and art classrooms (5.0). Two categories of buildings are included in the CEN proposal; Low-polluting buildings and Not-low-polluting buildings. Thevalues in Table 5 are used as guidelines fort he tvvo categories. To meet the requirements for "low polluting", a maximum of 20 % of the materials used in t he building must be from CategoryM2 and only an insignifıcant part from Category M3. per person and a rate per square meter floor area. The larger of the tvvo rates Categoıy M1* Categoıy M2 Category M3 is the minimum requirement. Maximum emission mg/m2.h Maximum emission mg/m2 .h * Emissions hihher 1VOC < 0.2 1VOC <0.4 than M1 and M2 H,CO < 0.05 H,CO < 0.125 NH, < 0.03 NH, < 0.06 * No emission data Carcinogenic Carcinogenic compounds < 0.0005 comoounds < 0.0005 * Category 1 according to IARC (WHO) classification in a Nordic guideline NKB-61 (NKB 1 991) a relatively simple procedure is recommended for calculating the minimum ventilation rate. A required ventilation rate per person (3.5 Us person) is added to the required ventilation rate per floor area (O.7 Us.mö). The total ventilation rate, however, must not be less than 7 Us per person. The basic requirements are the same for all types of spaces. (see Table 4). in the CIBSE Guide, the minimum required Table 5- Category of materials. ventilation rate is given as "per person". The basic requirements for all cited proposed standards and guidelines are given in Table 4 for four typical spaces. Except for ASHRAE 62-1989 R, all requirements are based on satisfying unadapted people, people who have just entered the space. in ASHRAE 62-1989 R, the minimum requirements are based on adapted people, people who already are in t he space. While the adaptation to body odor is significant, the minimum requirement per person is relatively small in ASHRAE 62-1 989R. The standard does, however, allow the designer to design for unadapted people. in t his case, 5 Us per person is added to the R values in Table 4. p Thevalues in Table 4 are not directlycomparablebecause of the different calculation methods used in the documents. The "person" values in DiN 1 946 include some ventilation to take careofthe building component, and the "building" value includes some ventilation to take care of the people component. For the simple systems procedure, a given people density is alreadyincluded. The values in prENV 1 752 are given for three classes where Class A corresponds to - 1 5 % dissatisfied, B to - 20 5 and Cto - 30%. The minimum ventilation rate perperson in ASHRAE 62-1 989R is always lower than the rates in the other documents. However, if the space is designed for unadapted persons, where 5 Us per person is added, then the values are comparable with Class B in the CEN proposal. The base value per person for offices in ASHRAE 62-1 989 R is 3 Us per person. This value also compensates for pollution Nale: Divide l/s by. 47/9 ta abtain f/min(cfm) The building value Rb in ASHRAE 62-1989 R uses as its basis 0.35 Us. mö, but does vary from space to space. Other examples listed in ASHRAE 62-1989R are; restaurant kitchen - 2.85, shopping mail - 0.30, and art classroom - 1.85. The building values (Table 4) in ASHRAE 62-1 989R are generally lower than the values in prENV 1752, but they correspond closely to the values for Class C The building value is assumed to be the same for adapted and unadapted persons, as the adaptation to pollution from building materials is small compared with the adaptation to human odor. A comparison of the listed standards of the required minimum ventilation rate for four typical spaces is listed in Table 6. The values in Table 6 for prENV 1 752 are calculated for "people", alone, and under "standard'' for low-polluting buildings. in addition, values forspaces with smokers areshown in Table 6. For the "standard calculation''ı the minimum required rates in ASHRAE 62-1989R are the lowest. in most cases, the rates are lower than Class C But the basis for the values also is different. While the minimum rates in ASHRAE 62-1989R are based on adapted persons, all the other documents are based on unadapted. lf unadapted values had been used, then ASHRAE 62-1 989R would correspond t o Class B in the CEN proposal. Analytical Procedure AII of the listed documents contain an analytical proce- - 1 •
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