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A. '( ASH RAE 62•1981 Ventilation for Acceptable Indoor Air Quality 'k. (01981 1791 Tulli. Clrcla„N.E, Atlanta, GA 30329 i

c TABLE OF CONTENTS FOBEWORn. pw ...................................................r Seedo.l Parpaes ........................................................2 3eedo.2 Seoye ..........................................................2 Secdos3 Ddlnitloe. ......................................................2 Sectlo. 4 (3amHeado. ...................................:..,..............2 Section S Spt- wid Equi4-t ............................................ 2 Seetlo.6 Proeed.re .......................................................4 5eetlo.6.1 Ye.tl4do. Rate PraeMare .......................................... ,4 Section 6.1.1 Acoxphbia Outdoor Air ............................................ 4 Section 6.1.2 Outdoor Air TreaDDea . ..................................... : ...... 5 Seedo. 6.1.3 Ye.Watlo. Req.iremead ........................................... 6 Section 6.1.4 Redte.lado. Gioerlr .............................................. ,6 Section 6.1.3 YaritbkOecapaoey .............................,...,............... 6 Section 6.2 Ldoor Air Qaall ty Proceduee ....................................... ,,11 Seedo. 6.2.1 Objeed.e Meamrement. ........................................... 11 Section 6.k2 Sabjeetl.e E.aluado...,... . ....................................... 12 Section 7 Refereeca ..................................................... 13 AYpeadkea ..................................................... 14 /

! ( FOREWORD When Standard 62-73~ was published, a comprehensive method of establishing ventilation rates was made available. That standard emphasized ventilation air quantitites in terms of volumetric air flow rates per petsonand introduced the eonceprof "acceptable outdoor air" for ventilation purposes. It also speci'- fied the conditions under which the outdoor air quality could be inaeased'through application of air clean- ing technology. Ventilation rates in Standard 62-73 were specified' as minimum and recommended values. The recom- mended values generally exceeded the minimum values by factors of 1.5 to 2. ASHRAE Standard 9a7S1 used mrnimum values for energy conservation purposes. ASHRAE Standard 90A-19801 reaffirmed'this approach. This constraint and new developments in air quality control dictated that Standard 62-73 be revised. . The revised Standard'includes a ventilation rate procedure which indirectly controls indoor air quality and'a new procedure to permit direct control of the indoor air quality. The latter method may see increas- ing use in the future, since it gives the engineer or designer more freedbm to achieve the objective of this Standard and to encourage innovative solutions. The objective of this revised Standard'is to provide healthful, and comfortable indoor environments by using materials and methods that optimize efficiency of energy utilization. Therefore, an interdisciplinary committee of engineers, physicians, chemists and psychologists was appointed to revise Standard 62-73. ASHRAE STANDARD 62-1981 t

EXHAUST OTHER AIR CLEANER LOCATION OUTDOOR ~-- - ,F AIR , (MAKEUP AIR) ALTERNATE PATHS FOR RECIRCULATED AIR ENERGY RECOVERY UNIT AIR CONDITIONING INFILTRATION UTHER AIR CLEANER LOCATION VENTILATING AIR OTHER AIR CLEANER ,//~LOCATIONS- _ i - GENERAL,i__ LL EXHAUST AIR CLEANER LOCATION ~ r~i ~ _ - ~-- LOCAL ~SUPPLY AIR ( ~ E-MAKEUP /1 j-- I _~ AIR ( OCCUPIED _ SPACE - LOCAL --~ EXHAUST I ------ ~-- ---~ LOCAL VENTILATIUN .....A.EXFIL-T-RATION * RETURN AIR -I Figure 1. Ventilation System 1 r ^ N i 00rySUCO

4. ~ C TABLE I NATIONAL AMBIENT AIR QUALITY STANDARDS• Coatamimmr- I.evel t.os{Term ~ Carbon Monoxide Lead 1.5 Nv/tn3 Nitrogen IToxide Oddants(Ozone) Particulates Sulfur qioxide 100 µg/tn~ 75 ygJm, 80 Ng/ m, C .. ShortTerm Tlme Lerel Time 40 mg/m3 t Hrl0 mg/m, 8 Hrs 3 Mo Yr 235µg/m~ 1 Hr Yr 2b0 yg/in3 24 Hts Yr 363 µg/m' 24 Hrs 7er Retema 1 ~. Pamm, lnm rtpYiuon rewN Wo ee chstM. smfe re<Wruoa mer a man ,avavn ~hY.o Nos V,m hee. and ad0i,ww wbaanm mry ee rap,iua TABLE2 ADD[TIONAL AMBIENT AIR QUALITY GUIDELINES Ce.orlms Lo.q Tam Simt Ta. Yd.eas to.d• Ttr l..d T1.e Acsw.--p". 7mi/mJ 2AHn. 24mvm3 30Min l2Aaolhn_p _ 23 vvm3 C... 13 . Ammooi.-O 0.3mYm3 Yr 7mvmj C 14;13 Bryllima 0.01 NaFm3' 30 Deys 13 Cad.,.m..,.. 2Ap/m3 24 Hn t6 CaldumOAde(Lime). 30-30yvm) C 17Cartion Disullidc--0 0.13 mvm3 ' 24 Hn 0.45 mpm, 30 Min 12 Chlorlee--O - O.Imvm3 24Hn 0.3.mg/m3 30Min 12Chromiam 1.3W/m3 7AHn 12. CreeW-0 0.l mvm3 24 Hn. 13 picAiotoahaoe-O 2Amvm3 b4Hn 6.0mI/m3 30Mio 12FjyylAanm-0~ l4mvm I 24Hn 42m6/m3 30Min I2FarmWe6yde-p. 120µvm3 C. l3HydtoddarieAad-o 0.4mvm3 24Hn3mt/m3 30Mtn 12.13 H3dlegm Sei{ide-p 40.50 w/m7 24 Hn 42 Nvm3 ' t Hr 17 (7 tmm) . M__P_n_p20yvm3' 1Ht l6MercarY . 2 Wlmj 24 Hn 16 Methyt Abo6oi-0 . 1.! mvm3 74 Hn 4.1 mvm3 30 Miu 12 Metayleee . 20 mvm3 Yr 130 mg/m, N! Min 14 . . CLloride-O 30m{/m3 24Hn 14 Nlekd 2W/mj 2414m l6. MtroomMonowdda 0.3mvmJ 24Hn - 1!mvm3 ]0MIa 14Fpenoi-0 at mvm, 24 Hn 12.13 $rltua 4pvmj' Yr . 1712yvmj ' 24Ho (4smralldrmieAed=O30wvm3 .' Yr IOOµvm3 30Mic14. t0pp/m7. 24Hn 14 Trichloret0yleae-0 2mvm3 Yr l6mvm,3' 30Min. 14. 3mvm~ 24Hn Yen.dium 2Nvm~ 24Hn 16 aet 30rvm, Yr t4. IOOyym1 24Hn 14 •uyday_yp.arkd,yt.r,pd,v mmesmnJU,lAbe-ud,eaanC.rdmnd'niemar2f'CRIFlumOeruunrn69E0mm.129.921rJelofmawtppsun.(101-3 kPe1. •'rfieu merid. merkad ..0•• Aeve odas u coeaau.uor.ome,oe roeee in a,WOm av. Th. ubuWd we,mnuoa 4.db do na ns.vwdr evu4i u odnrle. coemooe.. -'CeFiee. w moimme alb..er caaamur,am. air is not influenced by a source of substantial con- taatination. D. Air monitoring for three consecutive months, as required for inclusion in the National Aerometric Data Bank, shows that the air quality meets or exceeds the requirements of Table 1. Step 2: Outdoor air shall be considered unaccep- table if it is known to contain any contaminant at a con- centration above that listed in Table 2. This table covers other common contaminants for which no EPA am- blenr air quality standards existL 'i'hese levels were selected from current practices in various states, pro- vinces and other countries. vinces ministration". For application to the general popula- tion the concentration of these contaminants should not exceed 1/10 of the limits which are used in indtutry{see Appendix C). In some cases, this procedure may result in unreasonable limits. Expert consultationanay then be required. StepA: If after, completing steps l, 2 and 3, there is still a reasonable expectation that the air is unaccept- able, sampling shall be conducted in accordance with NIOSH procedures1470' Local' and' national aerometric data banks may contain information on some unregulated pollutants. Finally, acceptable quality should be evaluated using the definition in Section3.1. 6.1.2 Outdoor Air Treatment. If the outdoor air contaminant levels exceed the values given in Section 6.1.1, the air shall be treated to control the offending contaminants. Filters suitable for the particle size en• contami- nant 3: If the air is thought to contain any conami- nant not listed in Tables 1 or 2, guidance on acceptable exposure levels should be obtained by reference to the standards of the Occupational Safety and Health Ad- ASHRAE STANDARD 62-1981 5

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ventilation rates, which may bLulated by a method similar to those described in Appendix F, shallitie deter- nrined'by the designer. The effectiveness of this system adjustment shall be demonstratedi 6.2 INDOOR AIR QUALITY PROCEDURE: The ventilation rate procedure described above is assumed to provide acceptable indoor air quality, ipso jacto. Never- theless, that procedure, through prescription of re- quired ventilation rates, provides only an indirect solu• tiom to the control of indoor contaminants. A direct solution would bring the concentrations of contami- ttants to some specified,, acceptable levels. The indoor a. b. C. PROCEDURE c air quality procedure, described below; provides guide• lines for certain notable contaminants. It incorporates both objective measurement and'subjective evaluationk 6.2.1 Objective Measurement. Tabies I and 2 fur- nish information on acceptable contaminant levels in outdoor aIr. These tables also apply indoors for the same exposure times. Section 6.1.1. contains additional information on contaminants. In recenr years, problems have arisen from con- taminanu unrelated to occupancy, but rather generated' by the building itself and its contents. Examples include asbestos dust, radon gas, and vapors of formaldehyde Compute the air capacity per person in the space init"(m'). Find the required ventilation rate, in cfm (Us) per person. Enter Figure 2 with these values and read the maximum permissible ventilation lag time after occupancy from the intersection of a and b. Figure 2. Maximtm Permissible Ventilation Lag Time ASHRAE STANDARD 62-1981 11

C TABLE4 C SELECTED GUIDELINES FOR AIR CONTAMINANTS OF INDOOR ORIGIN Contaminanl Conantratlons^ExDoeuteTime Comments ( Aatone-O• Ammania-O Asbestos Known human carcin- ogen, best available control technology. Benuae-O Known human arcin- ogen, bat available control technology. Carbon Dioxidce 4.5 g/m3 ChlordAne-O 5 Ng/m3 Chlorine Cnesol-O Dichloromethane-O Fonnaidehyde-O 12D yg/mJ Hydraarbons. AliPhauc-O Hydroarboas. Aromatie-O Memuy Osone-0 100 yg/m3 Pftmol-O Radon 0.01 WorlongLevel(WL) Continuous . See Appendix D Continuous Reference 22 Continuous W. German and Dutch Guidelines Continuous Annualaveraje Reference 24 ParaglaPh 12.6 (backsround 0.002+ 0.004 WL.): Tetrachloroettiyleoe-0 Trichlaraettlane-_0 Tutpentine-O Vinyl Chloride-O Known human oudnogen, best available control technology. •ihsmuaiW mrW ••o•• h.w odws umecmvacr.omrtisa fosd ioiodom air. Tb. uEaWtl winenaooro do mc n®.nry rsYU m mals ®mtiem.. - Wh.- cam.oa. uaacYfa n(w to ]a.io.6.A.1.9Wp. N0: J. Tse. mbrana rM cr for.bm tndom apowwut uAnarm an na 7e..N.e/e.c nose, or throat. In an absence of objective means to assess the acceptability of such contaminants, the judg- ment of acceptability must necessarily derive from sub- jective evaluations of impartial observes. The air can be considered acceptably free of annoying contaminants if 80010 of a panel of at least 20 untrained'observers deems the air to be not objectionable under representative con- ditions of use and occupancy. An observer should enter the space in the manner of a normal visitor and should render a judgment of acceptability within 15 seconds. Fech observer should' make the evaluation indepen- dently of other observers and without influence from a panel leader. REFERENCES 1. "Standards for Natural and'Mahanical Ventilation," ASHRAE Standard 62-73 (ANSI' B 194:1-1977). American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. 2. "Energy Conservation In New Building Design," ASHRAE Standard 90-75, American Society of Hating, Refrigerating and Air-Conditioning Engineers,,Ihc. 3. "Energy Conservation In New Building Design," ANSI/ASHRAE/[ES Standard 90A-1980; American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. 4. "Thermal Environmental Conditions For Human Ocaapancy;" ASHRAE Standard SS-I981, American Society of Heating, Refrigerating and' Air-Conditioning Engineers, Inc. 5. "Factory Made Air Ducts and Air Duct Connecton,. UL 181," Underwriters Lab., 207 E. Ohio Street, Chicago, IL 60611. 6. National Fire Protection Association Std. 90A: Air- Conditioning and Ventilating Systems, 1978. National Fire Protection Association Std. 90B: Warm Air Heating and Air- ASHRAE STANDARD 62-1981 13

s velocity is no more than 2.2 m/s (5 C h). Commonly used exhaust fans st:ch as kitchm and bathroom exhaust fans should be turned' on. Flow of room air into the draft hood under these conditions must indicate a 40% dilutionu of the products of combustion going up the stack. This can be measured by measuring the room air temperature entering the draft hood„tHe stack temperature downstream from the draft hood, and the flue temperature at the combustion chamber outlet just upstream of the draft hood before the draft hood dilution air cools the flue gas.. Then Tr - T' _ 0:40 T. - T, Tr - Flue Temperature T, - Stack Temperature T, - Room Temperature If the stack temperature exceeds Tt+0.4T, T ~ ~ 1.4 under the measurement conditions defned above, a positive supply of outside combustion air is needed for safe operation of the furnace. Power burners of the type used in oil burners have a blower to supply combustion air. There must be enough air supplied to this type of burner to assure th'a the burner blower pro- duces the pressure rise specified by, the manufacturer. If a building is so tight that the blower cannot achieve its rated' ptesure rise, a positive supply of outdoor air must be pro- vided. Care must be exerdsed' with oil burners, however, if cold outdoor air is ducted directly to the burner, the low air temperature may degrade atomization and burner efficiency. The outdoor air provided should be temporary heat losa from the stack and furnace jacket. APPENDOL C RATIONALE FOR THE USE OF INDUSTRIAL STANDARDS OF EXPOSURE TO TOXIC AND HAZARDOUSSUHSTANCES Industrial health practice attempts to limit worker exposure to injurious substances at levels which do not interfere with the work process, and which do not injure the workers' health. The elimination of all effects, e.g.,,unpleasant smells or mild irritation, is not attempted. Regulations are based on the results of accumulated experience with worker health, and of animal experiments, carefully evaluated by groups of com- petent experts. Exposure and effects are related to dose of the injurious substance. Doae includes both the concentration of the substance and the time during which it is present. Since concentration commonly varies with time, dose is convenient- ly expressed as a time weigtited averge concentration (TWA), or threshold limit value (TLV). OSHA regulations are TWA's in most cases. These are explained with examples in the intro- duction to the reference tables". With some substances severe reaction may be present at certain exposure concentra- dons. Where this occurs a celing (C). or maximum allowable concentration (MAC), is imposed in addition to the TWA so that upward excursions in the exposure concentrations can be kept below the aitical level. Industrial exposures are regu- ]ated on the basis of a forty hour work week with 8 to 10 hour work days. The remainder of the time will be free ofahis expo- sure. Since public exposure to air contaminants may be con- tinuous rather than limited'to 40 hours per week, the TWA should be lowered in recognition of this difference. The work time exposure is appro dmately 1/5 of the houn in a year; thcefore,, the allowable concentration for the general' pubilc ASHRAE STANDARD 62-1981 C should first be reduced to 1/5 of its value. In addition, a fur- ther reduction to 1/10 is desirable because (1) the general pop- ulAtion is more varied than the industrial population in sus- ceptibility to injury due to greater variation in age and in health status, and (2) the industrial population is often under continual health supervision and the general population may not be. APPENDIX D RATIONALE FOR MINIMUM PHYSIOLOGICAL REQUIREMENTS FOR RESPIRATION AIR BASED ON CO= CONCENTRATION' Oxygen is necessary for metabolism of food to sustain life. Carbon and hydrogen in foods are oxidized'to COi and H=O which are eliminated by the body as waste products. Foods can be classified as carbohydrates, fats or proteins and the ratio of carbon to hydrogen in each is somewhat different. The Respiratory Quotient (RQ) is the volumetric ratio of ar- bon dioxide to the oxygen consumed. It varies from 0.71 for a diet of 1009% fat to 0.80 for a diet of 100% protein and 1 L0 for a diet of 100Nrcarbohydrater. A value of RQ - 0.83 applies to the normal mix of fat, carbohydrate and protein. The 03 required depends upon the activity level. At seden- tary activity levd; the O=, requirement is 0.0125 cfm. If we assume a person can consume 2S°74 of the 02 in air, then,, since air is about 21% 02, the air required for oxygen supply is [0.0125/(0.21x0.23)] - 0.24 cfm, clearly a small amount. There is no problem dissipating the H20 produced by .metabolism. The controlling physiological factor is the CO= concentra- tion in the inhaled aiu, not the O; limitation. People can fune- tion at levels of COi as high as I W. (as in nuclear submarines), but it is generally felt that 0.5 °h is a better limit (symptoms of high COz levels are headaches and loss of judgment)i If 0.3W. CO2 is taken as the limit, then C02 (inspired) - COl,(outdoor air) + 2V/V where CO= (outdoor) _ 0.03 % N'r generation rate of C0= - 0:63 ft3 /hr per person V- ventilation rate ft' /hr per person CO2 (inspired) ~ 4'4 concentration CO= (inspired) ~ (CO= (outdoor) + (0:63 x 100)/(cfm x 60)] ~ [CO= (outdoor)+ 1.05/cfm] Solving the equation when CO, is 0.5% and lower results in the following table for the required ventilation rate of out- door air per person ara sedentary activity level. 4aCOs Limit du/persos 0.5 2.25 0.4 2.86 0.3 3.92 0.25 5.00 0.2 6.23 0.1 15.10 For general ventilation standards, a limit value of CO= in the air is taken as about 0.25% as an additional safety factor, covering individual activity, diet and health variations. The minimum outdoor air requirement is then 5 cfm/person, and this standard speciGes that minimum. This must be supplied from sources outside the space, where COl levels are near 0.03% (as in outdoor air). The cfm/person is linear with metabolic level for the same COj level, and correspondingly higher limits are needed where activity is greater than sed- entary air volume per person is also linear with RQ: The effect of altitude is small, and no correction is considered necessary to 7,000 feet, thar being well within the safety factor. (An altitude or pressure correction table should be included for high altitudes and special chamben.) ~ 15