Self Pollution of Buildings

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Donna Flowers
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We glow wih selfrigheousness as we poin accusing fingers. This ar has been honed o such a perfec syle, ha facs become unnecessary, and conversaion he prime ingredien.

1 Self Polluion of Buildings J. F. SCHULZ. VanPacker Producs Co. Camden, New Jersey The figh agains polluion has become a glorious banner we all carry o demonsrae o ohers how deeply we are involved in preserving he comfor, he well being, he lives of mankind. We glow wih selfrigheousness as we poin accusing fingers. This ar has been honed o such a perfec syle, ha facs become unnecessary, and conversaion he prime ingredien. If we can smell i, if we can hear i, if we can see i, is polluion. The onsie incineraor has fallen vicim o each of hese senses, due no o heir overall conribuion o polluion, bu o a universal recogniion and he apparen imporance of nuisance as a complain producer. Modern incineraion can mee polluion codes and avoid nuisance problems. However, unless we recognize and undersand he condiions ha carry exhauss of all ypes back in o living areas, we will coninue o have problems, no only wih incinera0rs, bu also heaing appliances, kichen exhaus, air exhaus, or any polluion or nuisance bearing exhaus. Forunaely, no everyone has been playing he polluion game wih mouhs open and eyes closed. There are hose who have examined he facs and know somehing mus be done. These are he people who developed and passed he Clean Air Ac and i's 1970 amendmens, who esablished and operae he Environmenal Proecion Agency. This ac has wihin i he ools and elemens o conrql polluion. Our willingness o pay he price, when. we become payers, and o accep our responsibiliy, when we become paricipans, will be deermined as deadlines are achieved, and 1975, he final deadline arnves. We will no belabor he general polluion problems here, his is being handled adequaely by ohers. Our aim is o provide an awareness of polluion problems ha have a low visibiliy, hus lile appeal and less undersanding. The inen of his paper is o esablish an undersanding of he problems involved. Wih his knowledge we can eiher accommodae he principles wihin our buildings designs, or assume he responsibiliy by weighing he loss in esheics and economy agains he effec of polluans upon occupans. AlA FLOW OUT OF BUILDING A.. I A, I.. AIR FLOW OUT OF SHAFT A. CONTINUOUS VERTICAL SHAFT ELEVATOR SHA FT CHUTES STAIRWELL ZERO level AIR FLOW I AIR FLOW INTO INTO BUILDING SHAFT A.': OPENINGS CREATED BY CRACKS AROUNO WINOOWS WALL PORCSIT Y ETC. AI = OPENINGS IN THE FLOOR FOR PIPES DUCTS Erc. A.=SHAFT OPENINGS Fig. 1 An air flow paern in a heaed mulisory building. 201

2 AIR MOVEMENT WITHIN BUILDINGS We mus firs undersand he condiions wihin a building ha foser self polluion. The firs elemen of building polluions is he naural air movemen wihin i creaed by he chimney effec or difference in air densiy beween warm and cold air [1]. For a heaed building (Fig. 1), he cold ouside air pushes ino he building by infilraion and opening on he lower floors. The warmer inside air rises. I f we were o open a window as we proceed from floor o floor, we may observe he flow paerns. The inflow becomes less as we proceed upward, and finally reverses o an ouflow which becomes more inense as we proceed o higher floors. The zero poin or poin where flow is neiher in nor ou, is usually abou half he building heigh, bu may be higher or lower ranging from onehird o wohirds of he building dependen upon he ighness of he building [2]. The igher he building, he lower he zero poin. The zero poin will also vary wih wind condiions. During he air condiioning season, he flow is reversed (Fig. 2). We may now observe some basic problems. If we assume he verical shaf is a refuse chue wih sealed op, we noe air flow in a lower floors and ou on upper floors during he heaing season (Fig. 1), hus odors from he chue will ener he living areas on all floors above he zero poin. During he air condiioning season, he reverse effec will be rue, wih odors enering he living area below he zero poin. In he case of a flue fed incineraor, or bypass flue fed incincera or [3] where he chue serves as a chimney, he problems are compounded wih producs of combusion as well as chue odors creaing inolerable condiions. Clogging becomes serious, wih smoke peneraion pos 1 ;DE AIR O.071,11/cu. f. i fl: / / Fig. 2 An air flow paern in a cooled mulisory building. sible. Smoke will be carried hroughou he building by he normal air movemen wihin i, creaing a nuisance or serious source of danger dependen upon he magniude of he smoking. The oxic elemens of smoke are he killers in fires. FLue fed incinceraors wih combinaion chue and flue should never be used. The bes soluion o he naural building pressures in a building is he use of he chue fed incineraor where he chue can be placed under a negaive pressure overcoming he chue ouflow effec (Fig. 3). The draf inducer mus be properly designed, and mus operae coninuously on he chimney exhaus. Graviy ype refuse and linen chues no direcly conneced o an air movemen sysem o correc building pressures and chues which are no an inegral par of an incineraor presen special problems. A oo large door and oo narrow chue provide convenience in loading and economy in consrucion, bu he pison effec forces odors ou of he lower doors as he refuse ravels downward (Fig. 4). In hospial linen chues, his can be a high source of conaminaion, and an added problem o he already exising chue problem as demonsraed in Figs. 1 and 2. Safe pracice dicaes ha he door shall be no more han onehird he crosssecional area of he chue, and ha he chue shall be 30 in for buildings over seven sories high and 24 in. I.D. for buildings less han seven sories high. This crieria is based on amospheric chues and fire safey as well as proecion agains building polluion. N.F.P.A. No. 82 [4] requires chues o have an open op and exend (full size) a leas 4 f above he op of he building. The elevaion of he open chue op above he roof no only provides fire safey, bu in effec raises he zero poin of he chue o a poin above he uppermos opening, hus allowing all flow o be ino he chue during he heaing season (Fig. 5). This siuaion, however, does no ake ino accoun roof pressures, down drafs, or condiions during he air condiioning season where he chue flow paern can be reversed. I is a sep in he righ direcion, however, for chues o be problem free, hey mus be placed under coninuous negaive pressure o insure inflow a all imes. The chuefed incineraor, wherein a chue direcly or indirecly feeds an incineraor ha is exhaused by a negaive pressure chimney wih suiable inducer o place he enire sysem under negaive pressure, no only removes a refuse problem, bu eliminaes he poenial fire and nuisance value of oher sysems. A refuse handling sysem of grea poenial is he negaive pressure chue or air conveying mehod of refuse handling (Fig. 6). Negaive pressures well above naural or mechanical building pressures (17 in. or more) convey he refuse hrough a building and require ha all 202

3 c;: DRAFT INDUCER n DRAFT INDUCER ROOF REFUSE CHUTE J REFUSE CHUTE J CHIMNEY ] CHIMNEY BYPASS I LJ ' LESS THAN 10 STORIES MORE THAN 10 STORIES Fig. 3 Draf inducers overcome building pressures. Chues mainained under negaive pressures. ROOF I ROOF o POOR GOOO Fig. 4 Pison effec creaed by large package. Fig. 5 Open op raises zero poin. Small package allows chue air o be displaced wihin he chue. 203

4 r [ [ [ BUILDING [ GROUND LEVEL EXHAUST DISPOSAL Fig. 6 Pneumaic refuse handling sysem.. E 2 T E, o _w_ H l E =EDDY HEIGHT ABOVE ROOF Fig. 7 Eddy heigh remains consan wih building heigh depends upon building widh. air flow is direcly ino he chue. This avoids building conaminaion, if we consider he proper locaion of he erminal. This is a good and safe sysem. Chue diameers for his sysem may be as low as 18 in. since i is an air operaed conveyor sysem. The conrol of smoke, due o unfriendly fires in high rise consrucion, requires a close examinaion of air movemen wihin a building [5], wih he naural building pressures (chimney effec) and wind effec, having more influence han he pressure buil by fire. The usual mehod of vening involves high level openings. However, his mehod causes smoke o migrae according o he air movemen paerns. This almos always fills much of he building wih smoke, and smoke is he killer. High rise buildings have been overlooked as fire problems, because of heir definiion as "fire resisive buildings". However, he frequency of fires became eviden in he early 1960's. In almos all cases, deahs occurred, no by fire in he fire area, bu by smoke; ofen many sories removed from he fire. The recen fires in New York Ciy (one in midown Manhaan occurred in he 47sory Carpe Cener Building, and more recenly a One New York Plaza, a 50sory building) end o bring he problem ino sharp focus. Several mehods have been recommended for smoke conrol [6,7]. Pressurizing he sairwell provides a refuge for building occupans by allowing air o escape ino he building from he sairwell, hus keeping he smoke ou of a rerea area. I has been found, however, ha sairwells are oo small, ha doors are oo small, and congesion considerable. There is mouning evidence ha evacuaion hrough sairwells of high rise buildings is exremely difficul, if no impossible. Minimum sairway widhs of 44 in. have been recommended. Places of refuge should be provided on each floor wih sufficien floor area o accommodae 204

he enire occupancy of he floor. These areas mus be mechanically pressurized. The verical division of buildings is recommended where exreme precauions agains smoke hazard are required.

5 he enire occupancy of he floor. These areas mus be mechanically pressurized. The verical division of buildings is recommended where exreme precauions agains smoke hazard are required. Smoke can be removed from he fire area, hrough fire resisive verical shafs [8], which are designed wih normally closed openings a CHIMNEY TERMINATED ABOVE THE EDDY ZONE : EDDY AREA _/ Fig. 8 Produc of combusion blown clear of building. WIND FLOW UNAFFECTED BY BUILDING EDDY ZONE HEIGHT each floor, and an open op. When smoke densiy on any floor reaches an unaccepable level, from 1 o 2 percen, he door on he fire floor is opened and he naural building pressures will force he smoke ino he shaf and avoid peneraion o oher floors. The shaf diameer necessary o preven smoke ransfer from floor o floor, is approximaely hree imes he leakage area per sory of he ouside wall. For a ypical 20sory office building, a 7.5 f2, shaf is required. I will move 6660 cfm of air a a pressure of 0.27 in. of waer under naural exhaus condiions. Similar air flow would occur wih an exhaus fan of he same capaciy. The effec of his ype of smoke shaf is reduced significanly if he ouside wall is rupured or a window broken. I does provide an excellen means of smoke removal in hose siuaions where he exerior wall will remain inac. The magniude of he naural building pressure or chimney effec can be deermined by calculaing he heoreical draf [9] from he zero poin o he op of he building. For a 200 f high building his will be 0.26 in. waer. When we add in. waer for 30 mph wind pressure, we have a oal pressure of 0.69 in. waer o consider. Deailed pressure consideraions may be calculaed using he relaionships esablished by Tamura & Wilson [10] and by Barre & Locklin [11]. WINO WINO POLLUTENTS ENTER upper STORIES DURING THE AIR CONDITIONER SEASON POLLUTENTS ENTER THE LOWER STORIES DURING THE HEATING SEASON Fig. 9 Chimney erminaed in eddy area allows polluion o ener building.. S Ha H B H e ' 4 BASIC BUI LDING CUBE. "I MECHANICAL ROOM 80' BASIC BUILDING ENCLOSURE CUBE 8' 4' 1S' 4 Fig. 10 Chimney heigh achieved by building configuraion... AIR MOVEMENT AROUND BUILDINGS Air paerns around buildings have been subjec o considerable invesigaion. Exensive wind unnel ess and field confirmaion have provided some general rules. I has been found ha for a single basic cube; ha is, a building where he lengh equals he widh, he widh equals he heigh, he heigh of he eddy above he ground will be 1.5 imes he building widh [12], As we increase he number of cubes in heigh, we fmd ha his caviy heigh above he roof remains unchanged, and is approximaely half he building widh (Fig. 7). Having esablished he eddy heigh, we may now review is effec. For a chimney erminaed above he eddy area, here are no self polluing problems, since he exhauss are carried away from he building (Fig. 8). Wih a chimney erminaed below he eddy zone, he exhaus producs are carried back o he building o reener hrough air inakes or by infilraion. During he heaing season, polluans will ener he sories above he zero poin; during he cooling season, below he zero poin (Fig. 9). The boxype building wih fla roof and hidden roof appliances is popular, bu o erminae a chimney or exhaus sysem above his area, would require a 60 f chimney heigh for a 120 f wide building [13]. This is always objecionable o an archiec and provides oher prob 205

6 lems. I becomes a condensor o creae inernal moisure problems. Boh condiions may be solved by placing he chimney or exhaus duc wihin an enclosure as par of he mechanical room, o proec he chimney from cooling, and o allow projecion above he eddy (Fig. 10). We mus remember ha all building exhauss, boilers, incineraor, heaing chimney, air condiioning ec., reener he building by infilraion, or inake air ducs, unless he pressures involved are overcome, or he exhaus erminaed above he eddy area. The concenraion of hese effluens will deermine he degree of reconaminaion ha occurs [14, 15]. Unforunaely, his concenraion can be above accepable levels and in he case of carbon monoxide, can be undecable. The fenced roof and he parape wall are esheically adequae (Fig. 11), however, he pressures and condiions allow recycling of effluens ino air inake sysems [16]. Acid effluens [17] as from solid or liquid fuel heaing sysems, will be deposied on roof duc moors and roof equipmen o increase mainenance coss and sysem failure. Exhaus sysems erminaed under a parape wall will be under posiive pressure wih cerain wind condiions [18]. For an incineraor or boiler chimney, his can have an adverse effec upon he combusion process wih a high carbon monoxide and odor oupu. This could be forced from he appliance o conaminae he appliance room, and circulae hroughou he building. I should be poined ou here ha all appliances should have an adequae air supply if proper combusion is o occur. Open louvers are no answer, since hey end o be closed by personnel who objec o cold air during he winer season. A duced air supply o he appliance or heaed makeup air are possible soluions. Fig. 12 shows a chimney ha may be erminaed according o fire codes, bu a frequen source of rouble for all ypes of appliances and exhaus sysems. I is paricularly a problem for fireplaces where downdrafs carry smoke and ashes ino living quarers. A chimney erminaed below he eddy area, or below a parape wall or below a higher building will be subjec o posiive pressures. These will.force he producs of combusi;m bjck ino he building regardless of downdraf caps. These caps are good only o avoid downdrafs associaed wih wind direcion [19]. The effec of wind on an eddy area of low buildings is ofen overlooked in he deerminaion of chimney heighs. We end o adhere o codes designed only for fire safey. Wind unnel ess have shown he same air flow effec as he high rise, however, in he case of low buildings. The widh of he eddy area becomes imporan. CHIMNEY HEAT AIR ROOF EXHAUST INTAKE APPLIANCE Fig. 11 Parape walls allow circulaion of polluans. WIND.. POSITIVE PRESSURE ZONE CHIMNEY Fig. 12 Obsrucion creaes posiive chimney pressure (double draf). 206

Wind builds up ino an eddy area wih a heigh equal o onehalf of he building heigh, bu moves closer o he roof as he widh of he building exceeds wo imes is heigh (Fig. 13).

If a chimney is locaed on or wihin 2H of he edge of a 20 f high building, he chimney heigh mus be 10 f above he parape wall o be above he eddy area [12].

7 Wind builds up ino an eddy area wih a heigh equal o onehalf of he building heigh, bu moves closer o he roof as he widh of he building exceeds wo imes is heigh (Fig. 13). This places he building edge as he mos criical porion of low buildings. If a chimney is locaed on or wihin 2H of he edge of a 20 f high building, he chimney heigh mus be 10 f above he parape wall o be above he eddy area [12]. The level of he roof does no deermine he heigh of he chimney. This is deermined by he heigh of he highes poin in conac wih he wind. Thus in Fig. 14, he YlH H EDDY AREA, H. 1 BUILDING BROKEN INTO BASIC CUBES WHERE H= W Fig. 13 Eddy heigh wih low buildings. building heigh, plus he parape wall, becomes he conrolling heigh. Wih his heigh as 20 f, he chimney heigh mus be 10 f above he parape wall or 14 f above he roof. I is in line wih good design o locae a chimney above he eddy area (Fig. 15). This area becomes lower as we move from he edge hus a lower chimney is possible, ye sill above he eddy area. Removal from he building edge has he furher effec of raising he line of sigh above he normal viewing heigh. Terminaion of a chimney or exhaus sysem below he eddy area and close o he roof edge allows recycling of exhaus producs ino he air inake o conaminae he enire building (Fig. 16). A coolie cap and mos chimney capo defea he proper funcioning of a chimney even hough designed o be above he eddy area (Fig. 17). The cap forces he polluans below he eddy area and close o he roof where hey can be recirculaed ino he building by air inakes or infil ra ion. I is good procedure o eliminae he rain cap and use a ee and pier suppored chimney wih a drain. This will remove boh rain and condensaion (Fig. 18). 10' 4' 4 4' + ROOF LINE WINO 20' Fig. 14 Eddy heigh deermined by heigh of resisance area. POLLUTANTS CARRIED AWAY FROM AIR INTAKE / EDDY AREA AIR INTAKE DRAIN GOOD DESIGN CHIMNEY NOT VISIBLE FROM STREET Fig. 15 Chimney erminaed above eddy area avoidsflow ino building. 207

8 EDDY AREA.. CHIMNEY AIR INTAKE POOR DESIGN Fig. 16 Chimney erminaed below eddy area allows recirculaion of polluans ino building. EDDY AREA AIR INTAKE Fig. 17 Rain cap forces polluans oward building. 208

Chimneys may be suppored from he roof where space is imporan. The supporing member mus be provided wih a drain (Fig. 19). When a rain cap is absoluely necessary, a zero loss cap may be used (Fig. 20).

When pressure exhaus sysems are involved, such as conrolled air incineraion or urbine or diesel exhaus 1 I'""" I 11 I :::?

This will keep he combusion producs confilled as hey should be. This appears obvious, bu is a frequen failing (Fig. 21). REFERENCES [I) G.

9 Chimneys may be suppored from he roof where space is imporan. The supporing member mus be provided wih a drain (Fig. 19). When a rain cap is absoluely necessary, a zero loss cap may be used (Fig. 20). This provides an annular area around he inside of he chimney, for waer removal. Fig. 19 presens one design; ohers may be found in Clark's paper [14,20] or in Indusrial Venilaion. When pressure exhaus sysems are involved, such as conrolled air incineraion or urbine or diesel exhaus 1 I'""" I 11 I :::? " DRAIN ROOF APPLIANCE on sandby elecrical generaors, proper expansion fiings beween he urbine and he chimney and a pressure igh chimney, preferably wih welded joins should be used. This will keep he combusion producs confilled as hey should be. This appears obvious, bu is a frequen failing (Fig. 21). REFERENCES [I) G. T. Tamura and A. G. Wilson, "Pressure Differences Caused by Chimney Effec in Three High Buildings," paper presened a he ASHRAE 74h Annual Meeing, Minneapolis, Minn., June 2628,1967. (2) J. F. Schulz, "Facors Involved in he Design of High Rise Chimney and Chue Sysems," Proceedings of 1968 Naional Incineraor Conference, ASME, New York, N. Y., (3) J. F. Schulz, "Incineraion Air Polluion and Aparmen Buildings," Comfor Engineering, Winer 1966/67 issue. (4) Sandard on Incineraors and Rubbish Handling, no. 82, Naional Fire Proecion Associaion, (5) J. H. McGuire, "Smoke Movemen in Buildings ", Fire Technology, vol. 3, no. 3, Augus 1967, pp (6) J. H. McGuire, "Conrol of Smoke in Building Fires," Fire Technology, vol. 3, no. 4, Nov. 1967, p (7) A. G. Wilson and G. W. Shorer, "Fire and High Buildings," Fire Technology, vol. 6, no. 4, Nov. 1970, p [8] G. T. Tamura and A. G. Wilson, "Naural Vening o Conrol Smoke Movemen In Buildings via Verical Shafs," paper presened a ASH RAE Annual Meeing, Kansas Ciy, Mo., June 28July 1, (9). J. G. Mingle, "Draf and Capaciy of Chimneys," Combusion Publishing Corp., (10) G. T. Tamura and A. G. Wilson, "Building Pressures Caused by Chimney Acion and Mechanical Venilaion," paper presened a he ASHRAE 74h Annual Meeing, Minneapolis, Minn., June 2628,1967. Fig. 18 Eliminaion of cap projecs polluans upward. ROOF DRAIN 0... APPLIANCE.. Fig. 19 Roof suppored chimney. Fig. 20 Zero resisance roof erminaion. 209

[11 I Rich,ud E. Barre and David W. Locklin, "A Compuer Technique for Predicing Smoke Movemen in Buildings," Fire Technology, vol. 5, no. 4, Nov. 1969, p. 299. [121 Benjamin H.

10 [11 I Rich,ud E. Barre and David W. Locklin, "A Compuer Technique for Predicing Smoke Movemen in Buildings," Fire Technology, vol. 5, no. 4, Nov. 1969, p [121 Benjamin H. Evans, "Naural Air Flow Around Building," The Texas A & M College Sysem, Research Repor No. 59, March [131 J. Halisky, "Gas Diffusion Near Buildings," paper presened a he ASHRAE 70h Annual Meeing, Milwaukee, Wisc., June 2426,1963. [14] 1. Halisky, "Esimaion of Sack Heigh Required o Limi Conaminaion of Building Air Inakes," American 111 dusrial Hygiene Associaion Journal, vol. 26, [15] P. S. Rummerfield, J. Cholak, and J. Kereiakes, "Esimaion of Local Diffusion of Polluans from a Chimney," American Indusrial Hygiene Associaion Journal, vol. 28, no. 4, JulyAugus 1967, p r 161 J. H. Clarke, "Air f'low Around Buildings," Heaing Piping and Air Condiioning, May 1967, p [17] "Conrol of Corrosion and Deposis in Saionary Boilers, Burning Residual Fuel Oil," AD422073, Governmen Research Repor, U.S. Deparmen of Commerce, Office of Technical Services. [18] E. S. Holdredge and R. H. Reed, "Pressure Disribuion on Buildings," Summary Repor No. 1 o he Deparmen of he Army, Camp Derick, Md., Augus 1956, Texas Engineering Experimen Saion. [19] E. H. Perry and J. J. Vandeber, Jr., "A Sudy of Ven Cowl Performance and Locaion," Research Repor No Heaing and Air Condiioning Research, American Gas Associaion. [20] Commiee on Indusrial Venilaion, "Indusrial Venilaion A Manual of Recommended Pracice," 10h ediion, A merican Conference of Governmenal Indusrial Hygieniss, p. 85. GUV BANDS {lily V,P., STIFF leg GUYS (BY OTHERS) _ STAAIGHT SECTIONS PIEce WITH TRANS!T!ON section 1.0.1!. SECTION 0.0. RING ON ONE END AND STANQARD PIPE FLANGe ON OTHER END (BV OTHERS, VIEW "A"_""" URBINE GENEHATOR SET SMO+<e nght CLEANOUT secion STEEL SUPPORTS (BY OTHERS) Fig. 21 Posiive pressure chimney. 210

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