Aville online t www.sciencedirect.com ScienceDirect Procedi - Socil nd Behviorl Sciences 184 ( 2015 ) 289 296 5th Arte Polis Interntionl Conference nd Workshop Reflections on Cretivity: Pulic Enggement nd The Mking of Plce, Arte-Polis 5, 8-9 August 2014, Bndung, Indonesi The Design nd Model of Dylighting Control System for Ssn Budy Gnesh Underground Tunnel FX Nugroho Soelmi *, Estiynti Ekwti, Vernid Mufidh, Astr Goldie Auli Engineering Physics Progrm, Fculty of Industril Technology, Institut Teknologi Bndung, Bndung, Indonesi Astrct Ssn Budy Gnesh Institut Teknologi Bndung (Srg ITB) Tunnel is n underground tunnel connecting ITB Cmpus with the Srg Sports Center. Despite eing n underground tunnel, the originl design of Srg Tunnel ws to utilize dylight. It hs two skylights nd fitted mirrors to distriute dylight cross the tunnel. In order to study the potentil of the dylighting inside the tunnel, this study developed simultion model of light distriution inside the tunnel. The model s prmeters included the geometry of the tunnel; the photometric properties of inside surfces, i.e. the reflectnce, trnsprences, nd colors; the geometry of skylight, nd the resulting illuminnce. This result demonstrted the potentil use of dylighting control system of Srg Tunnel. 2015 The Authors. Pulished y y Elsevier Elsevier Ltd. Ltd. This is n open ccess rticle under the CC BY-NC-ND license (http://cretivecommons.org/licenses/y-nc-nd/4.0/). Peer-review under responsiility of the Scientific Committee of Arte-Polis 5. Peer-review under responsiility of the Scientific Committee of Arte-Polis 5 Keywords: dylighting; tunnel; mirror reflector; control system 1. Introduction One mjor chllenge with n underground tunnel is to distriute nturl light inside its corridor (Hopkirk nd Breer, 2000). One of such tunnel is the Ssn Budy Gnesh (Srg) Tunnel in the city of Bndung, Indonesi. This tunnel connects the cmpus of Institut Teknologi Bndung (ITB) with the Ssn Budy Gnesh Sports Center. The tunnel fcilittes 45 m long, 4.5 m height nd 9 m width of wlkwy underneth the Siliwngi rod tht seprtes these loctions. Figure 1 shows the ppernce of the tunnel s gte t the cmpus side. * Corresponding uthor. Tel.: +062-022- 2504424; fx: +062-022-2514287. E-mil ddress: nugroho@tf.it.c.id 1877-0428 2015 The Authors. Pulished y Elsevier Ltd. This is n open ccess rticle under the CC BY-NC-ND license (http://cretivecommons.org/licenses/y-nc-nd/4.0/). Peer-review under responsiility of the Scientific Committee of Arte-Polis 5 doi:10.1016/j.sspro.2015.05.093
290 FX Nugroho Soelmi et l. / Procedi - Socil nd Behviorl Sciences 184 ( 2015 ) 289 296 Fig. 1.The south gte of Srg tunnel. For round fifteen yers fter its opening in 1996, the tunnel ws operted only to fcilitte pedestrin pth etween ITB cmpus with Srg Convention Center during the grdution dys in April, July nd Octoer every yer. Since 2012, the tunnel opened for pedestrin, mostly students nd stffs, during workdys, from 6.00 m to 5.00 pm. As shown in figure 1 nd 2, the services such s cnteens just next to the tunnel s gtes, exhiits of student s posters nd tles long the wlkwy, photocopy service, ATM ooth nd convenience store; ll mrked the significnt increse of ctivities inside the tunnels. Both pedestrins who spend less thn 30 minutes inside the tunnel nd stffs who operte the services for t lest 8 hours during the weekdys inside the tunnel could enefit from proper use of dylight. Studies hve shown tht proper use of dylight enhnces the ppernce of the wlkwy, excite positive moods of stffs nd improves the eye dpttion of pedestrins (Edwrds nd Torcellini, 2002). Hving tht concept in mind, the originl design of the tunnel incorported two skylights, A nd B, s shown in figure 3. These were equipped with reflectors (mirrors) s shown in figure 4. Unfortuntely, due to long nonopertionl stte of the tunnel, some of the reflectors were long gone. Tody, rtificil lighting supports the ctivities inside the tunnel throughout the opertionl hours. In spirit to revive dylighting of the Srg Tunnel, this pper presents dylighting simultion nd control strtegy inside the tunnel. The simultion prmeters re the geometry of the tunnel; the photometric properties of inside surfces, i.e. the reflectnce, trnsprences, nd colors; the geometry of skylights, nd illuminnce otined. This study ssumes tht ech skylight hs set of reflectors, nd the reflector s ngle cn e vried to find the mximum dylight penetrtion in the corridor. c d Fig. 2.Services inside the tunnel.() exhiition re nd study desks;() photocopy services;(c) ATM ooth; (d) convenience store.
FX Nugroho Soelmi et l. / Procedi - Socil nd Behviorl Sciences 184 ( 2015 ) 289 296 291 Fig. 3.The site pln of Srg Tunnel. A nd B mrk the loction of skylights [2]. Fig. 4.Skylight nd remins of the reflectors. To vlidte the simultion results, 1:20 scle miniture model of the tunnel with n utomtic dylight control system is developed. This system rottes the reflectors using stepper motor. A microcontroller controls the reflectors ngle sed on the mesurement of illuminnce t the principl points. The trget is to control the reflector s ngle to chieve the mximum dylight distriution throughout the tunnel. 2. Dylighting simultion in Srg Tunnel Dylighting is defined s plcing openings, reflective surfces nd other forms of fenestrtion (such s windows, skylights, light shelves, light tues, etc) to ring nd distriute nturl light into the interior of uildings during the dy. Before 1940s, dylight ws the primry light source in uildings. However, in the short spn of 20 yers, electric lighting hs trnsformed the workplce y meeting most or ll of the occupnts lighting requirements. Recently, energy nd environmentl concerns hve mde dylighting rediscovered spect of uilding lighting design (Bker nd Steemers, 2002). The nturl light sources for this purpose cn e the direct sunlight or the diffuse dylight. The ltter is preferle for indoor lighting due its diffuse nture nd its ese of shde nd glre control. Vrious solutions for dynmic lighting or glre controls re ville through motorized nd utomted louvers or reflectors. Once properly instlled nd configured, the position of the reflectors cn e djusted to mximize the interior s luminnce when the mient lighting chnges. The development of control design is ssisted y computer nd ppliction softwre tht simulte the dylight distriution (Edwrds nd Torcellini, 2002; Fchrizl, 2008; Hopkirk nd Breer, 2000). Such pproch is underwy for Srg tunnel. The existing two skylights nd wide gtes re dylight sources of Srg tunnel. Accordingly, this study developed full-scle simultion model to oserve the effect of the diffuse lighting through the gtes nd skylights, nd the effects of reflector s ngle nd configurtion illuminnce inside the tunnel. The simultion uses Dilux 4.11 softwre. The simultion conforms to IESNA stndrds for pedestrin tunnels tht require 43 lux of the minimum verge illuminnce t horizontl plne, nd 54 lux for the verge illuminnce t verticl plne for pedestrin
292 FX Nugroho Soelmi et l. / Procedi - Socil nd Behviorl Sciences 184 ( 2015 ) 289 296 security (IESNA 2000 nd 2003). The dylight dt is specified for Bndung city locted t 107º E nd 6º 55 S. The sky condition is ssumed cler nd right. The ssumptions for simultion re s follows: The externl light penetrtes the tunnel through diffused surfce with 40% trnsmission fctor. The light through the skylights goes into distriution chmer of 4 x 2 x 4.9 m with 50% reflection fctor. The tunnel s interior is covered entirely with white cermics tiles with 67% reflectnce fctor. Two configurtion of the reflector re considered: () single reflector of 1.5 x 4 m nd () three reflectors, ech of 0.75 x 4 m. The reflectnce fctor is 70%. The reflectors re illustrted in figure 5. The illuminnce is clculted t the work plne, 0.75 m ove the ground level. Norml Reflector Pivot = Reflector s Angle Fig. 5.The reflector s configurtion. () Single reflector () multiple reflectors. During the first round of the simultion, the single reflector is used. The reflector s ngle is vried from 10 80. The resulting mximum nd minimum illuminnce throughout the tunnel re summrized in figure 6. The vrition of the mximum level is 0.03%. This is negligile in comprison to the vrition of the minimum illuminnce, which is 3.07%. Illuminnce vs Reflector's Angle Illuminnce (lux) 102 100 98 96 94 92 90 88 86 3678 3677 3676 3675 3674 3673 3672 3671 0 20 40 60 80 100 Reflector's Angle ( ) Emx Emin Fig. 6.The effects of reflector s ngle to the mximum (right scle) nd the minimum illuminnce (left scle) inside the tunnel. At = 60, the verge illuminnce throughout the tunnel ttins its mximum t 325 lux. The light distriution throughout the tunnel t this condition is illustrted in figure 7. The figure shows tht the skylight B nd the north gte provide sufficient dylight to support the service ctivities for the surrounding re during the right dylight. The light through skylight A nd South gte, however, ech cn only rech less thn hlfwy of the tunnel. The illuminnce t the drkest re in figure 7() is 99 lux. Such level is sufficient for pedestrin wlk, ut not for supporting reding the students exhiits long the tunnel. This point ecomes the principl point, t where illuminnce is mesured. This illuminnce level triggers the ctivtion of the dynmic dylight control system.
FX Nugroho Soelmi et l. / Procedi - Socil nd Behviorl Sciences 184 ( 2015 ) 289 296 293 Fig. 7.() Work plne clcultion nd () Flse color rendering of dylight distriution using single reflector t = 60. Figure 8() shows the dylight distriution y three reflectors t = 60, 45 nd 30. It shows tht multiplying the reflectors produce higher illuminnce (1-3 lux) throughout the tunnel. However, sttisticl T-student test to this result sttes tht this increse is not significnt, neither t 5% nor 1% degree of confidences. This shows tht the current configurtion of multiple reflectors does not improve the light distriution inside the tunnel. For this reson, other mens of distriuting dylight need to e considered, such s chnging the configurtion nd the reflector mteril. Fig. 8. Work plne clcultion for light distriution y () single reflector t 60, nd () multiple reflectors t = 60, 45 nd 30.
294 FX Nugroho Soelmi et l. / Procedi - Socil nd Behviorl Sciences 184 ( 2015 ) 289 296 3. Automtic Dylighting Control In Model Scle Controller & Driver Reflector South Gte Appernce Fig. 9. The 1:20 scle miniture model of Srg tunnel. To vlidte the simultion results, 1:20 scled miniture model is prepred. As shown in figure 9, the wlls t one side of the tunnel re left open, to fcilitte the oservtion of light distriution inside the tunnel. At this stge, the model hs only one skylight, nd it mens only utilizing one dynmic dylight control. The control system consists of microcontroller, motor drivers, stepping motors, reflectors, potentiometers, light sensor nd signl conditioners. The control digrm is shown in figure 10. Fig. 10.The dylight control digrm.
FX Nugroho Soelmi et l. / Procedi - Socil nd Behviorl Sciences 184 ( 2015 ) 289 296 295 The control system works when the externl dylight is higher thn the minimum level required for illuminting the tunnel. The light sensor mesures the illuminnce t the principl point. If the illuminnce is lower thn the referenced level, microcontroller sends ctivtion pulse to the motor so tht it rottes the reflector. The potentiometer nd light sensor respectively mesures the rottion nd the resulting illuminnce t the principl point. Microcontroller receives the mesurement signls nd decides to continue rotting the reflectors or to stop rottion t n ngle tht produces mximum illuminnce t the principl point. Bsed on the stted procedure, two dylight control progrms hve een developed. The first control progrm ims to rotte the reflector to the designted ngle. This gol of this procedure is to compre the results of dylight simultion with the model scle implementtion. The second control progrm ims to rotte the reflector until the referenced illuminnce t the principl point is chieved, or if the mximum possile illuminnce is chieved. The pseudocode of the first progrm is s follows: E(0) = 0, E d(0) = E dmin, (0) = 0, U(0) = 0, k = 0 while operte = true if E d(k) E dmin if (k) < r, then U(k)=1 else if (k) > r, then U(k) = -1, else U(k) = 0, end if end if end if k = k+1 end while The pseudocode of the second progrm is s follows: E(0) = 0, E d(0) = E dmin, (0) = 0,U(0) = 0 = tn((4.5-y r-y p)/x p), k = 0 while operte = true if E d(k) E dmin if E(k) E r nd (k) /2,then U(k) = 1 else U(k) = 0, end if else if (k) > 0,then U(k) = -1else U(k) = 0, end if end if k = k+1 end while Here, E(k) is the illuminnce t the principl point (x p, y p) t time t k, E d(0) is the dylight, E dmin is the minimum dylight required to illuminte the tunnel. At the reflector system, (k)is the reflector s ngle, U(k) is the motor ctivtion signl nd is the ngle formed y the principl point, the reflector s center (0,y r) nd the skylight s center (0,0). The mximum reflector s ngle is mx = /2, t which dylight is reflected directly to the principl point. The control system is evluted y plcing 500 W hlogen lmps t the skylights of the model. The lmps re positioned in such wy tht the illuminnce entering the skylight is 5000 lux. This vlue represents the mesured illuminnce just outside the tunnel s skylight on cler nd right dy. The illuminncet the principl point is mesured in two conditions: without nd with dylight control. Without the control, illuminnce t the principl point is 36 lux. Here dylight control significntly improves the illuminnce t the principl point nd hence the overll luminnce of the tunnel surfces. The mximum illuminnce t the point is 79 lux, chieved t = 57.6. The profile of illuminnce t the principl point is similr to figure 6, ut round 20 lux lower. This shows tht the optimum reflector s ngle is modertely close to the simultion s result. However, the illuminnce t the principl point of the model differs significntly to the simultion results. The difference is due to the reflectnce fctor of the model s interior wll. The simultion ssumes tht white cermic tiles cover the whole tunnel s wll. This mteril hs higher reflectnce fctor thn the white crdord used in the scled model. This
296 FX Nugroho Soelmi et l. / Procedi - Socil nd Behviorl Sciences 184 ( 2015 ) 289 296 significntly reduces the illumintion t the principl point, either with or without the dylight control. Nevertheless, the experiment shows tht in overll dylight control significntly improves the light distriution inside the tunnel. This promising result deserves further with other configurtion of multiple reflectors. The ssumed concve configurtion is etter t focusing the light to certin point, ut not s good on distriuting the light cross the uilding. In ddition, when the concve reflector is operted to illuminte the point t lower work plne, only frction of dylight is cptured nd is focused to the designted point. A convex reflector configurtion, the use of prisms or even the light tue (Fchrizl, 2008; Hopkirk nd Breer, 2000) might e etter lterntives for distriuting the dylight to the work plne nd cross the tunnel. Further lso works underwy for full-scle implementtion of dylight control in the tunnel. The effect of incresing dylight to the productivity of occupnts (Edwrds nd Torcellini, 2002) is prospective topic for multidiscipline collortion etween rchitects, lighting nd control engineers nd ergonomic engineers. 4. Conclusions The existing two skylights nd wide gtes offered vrious possiilities to use dylight in Srg tunnel. The simultion of dylight distriution through the skylights nd gtes showed tht single reflector t ech skylight t 60 ngles yielded mximum illuminnce inside the tunnel. At this configurtion, the level t the drkest point inside the tunnel (principl point) is 99 lux. This ws dequte for pedestrin wlk, ut not for ctivities such s reding or studying. The simultion using three reflectors t ech skylight did not show significnt improvement. This indicted the need for exploring different reflector s configurtion nd mterils in future studies. The implementtion using motorized mirrors cting s reflectors to distriute light inside 1:20 scled model of the tunnel vlidted the simultion results. The optimum reflector s ngle ws 57.6, which ws modertely close with the simultion result. The illuminnce t the principl point inside the tunnel is 20 lux lower thn the expected, due to the difference in wll mterils used y the model. Nevertheless, this showed the potentil of dylight control inside the tunnel. More lterntive dylighting methods require further investigtion. These include finding the optimum configurtion nd mteril of the reflectors, up to providing light tue long the tunnel. Implementing these solutions nd nlyzing the effects of the occupnt s mood nd productivity is n exciting multi-disciplinry work for rchitects nd engineers. Invittion for collortion is wide open to implement the full-scle dylighting the tunnel. Acknowledgements The uthors would like to thnk Arind Puspit Rchmn, Prji Adminto, Sutriyn, Irvn Budiwn, Rin Ferini, Deden nd Eko Rhyu Tli Jiw for their supports in prepring the miniture models, hrdwre nd documenttion for this reserch. References Bker, N., & Steemers, K. (2002).Dylight design of uildings. London: Jmes & Jmes Ltd. Direktort Srn dn Prsrn ITB. (1994).Blueprint terowongn Srg ITB. Bndung: Institut Teknologi Bndung. Edwrds, L., & Torcellini, P. (2002).A literture review of the effects of nturl light on uilding occupnts. Colordo: Technicl Report. Fchrizl.(2008). Pemndu chy mthri untuk penchyn lmi di ngunn.jurnl Sins dn Teknologi Indonesi,10, 3. Hopkirk, N., & Breer, D., (2000).Dylighting of tunnels. Duendorf: EMPA. IESNA (2000).Lighting Hndook(9th ed.). New York: Illuminting Engineering Society of North Americ. IESNA (2001).Advnced lighting guide. New York: Illuminting Engineering Society of North Americ. IESNA (2003).Guideline for security lighting for people, property, nd pulic spces. New York: Illuminting Engineering Society of North Americ.