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Life Cycle Assessment of Solar Façade Concepts Based on Transparent Insulation Materials

Struhala, Karel; Čekon, Miroslav; Slávik, Richard

Abstract

Contemporary architects and the construction industry are trying to cope with increasing requirements concerning energy efficiency and environmental impact. One of the available options is the active utilization of energy gains from the environment, specifically solar energy gains. These gains can be utilized by, for example, solar walls and facades. The solar façade concept has been under development for more than a century. However, it hasn’t achieved widespread use for various reasons. Rather recently the concept was enhanced by the application of transparent insulation materials that have the potential to increase the efficiency of such façades. The presented study evaluates the environmental efficiency of 10 solar façade assemblies in the mild climate of the Czech Republic, Central Europe. The evaluated façade assemblies combine the principles of a solar wall with transparent insulation based on honeycomb and polycarbonate panels. The study applies Life-Cycle Assessment methodology to the calculation of environmental impacts related to the life cycle of the evaluated assemblies. The results indicate that even though there are several limiting factors, façade assemblies with transparent insulation have lower environmental impacts compared to a reference assembly with standard thermal insulation. The highest achieved difference is approx. 84% (in favour of the assembly with transparent insulation) during a modelled 50-year façade assembly service life.

Full text

sus ainabili y A icle Li e Cycle Assessmen o Sola Façade Concep s Based on T anspa en Insula ion Ma e ials Ka el S uhala, Mi osla ˇ Cekon * and Richa d Slá ik Facul y o Ci il Enginee ing, B no Uni e si y o Technology, AdMaS Cen e, 602 00 B no, Czech Republic; [email p o ec ed].cz (K.S.); [email p o ec ed].cz (R.S.) *Co espondence: [email p o ec ed].cz; Tel.: +420-541-148-078 Recei ed: 19 Oc obe 2018; Accep ed: 12 No embe 2018; Published: 15 No embe 2018   Abs ac : Con empo a y a chi ec u e and cons uc ion indus y a e ying o cope wi h inc easing equi emen s conce ning ene gy e iciency and en i onmen al impac s. One o he a ailable op ions is he ac i e u iliza ion o ene gy gains om he en i onmen , speci ically sola ene gy gains. These gains can be u ilized by, o example, sola walls and acades. The sola açade concep has been unde de elopmen o mo e han a cen u y. Howe e , i has no achie ed widesp ead use o a ious easons. Ra he ecen ly he concep was enhanced by he applica ion o anspa en insula ion ma e ials ha ha e he po en ial o inc ease he e iciency o such açades. The p esen ed s udy e alua es he en i onmen al e iciency o 10 sola açade assemblies in he mild clima e o he Czech Republic, Cen al Eu ope. The e alua ed açade assemblies combine he p inciples o a sola wall wi h anspa en insula ion based on honeycomb and polyca bona e panels. The s udy applies Li e-Cycle Assessmen me hodology o he calcula ion o en i onmen al impac s ela ed o he li e cycle o he e alua ed assemblies. The esul s indica e ha e en hough he e a e se e al limi ing ac o s, açade assemblies wi h anspa en insula ion ha e lowe en i onmen al impac s compa ed o a e e ence assembly wi h s anda d he mal insula ion. The highes achie ed di e ence is app ox. 84% (in a o o he assembly wi h anspa en insula ion) du ing a modelled 50-yea açade assembly se ice li e. Keywo ds: building; en i onmen al impac s; açade; Li e-Cycle Assessmen ; anspa en insula ion; low-emissi i y 1. In oduc ion I is gene ally accep ed ha echnological ad ances combined wi h human popula ion g ow h a e ha ing a signi ican impac on he en i onmen [ 1 ]. Some au ho s e en compa e i o he ex inc ion e en s ha wiped ou mos li e o ms on Ea h in he pas [ 2 ]. Such s a emen s may seem exagge a ed; howe e , he slow change in he global clima e (e.g., ising a mosphe ic CO 2 le els [ 3 ]) is well documen ed. To add ess he issue, scien is s and poli icians ha e in oduced di e en “sus ainable de elopmen ” s a egies such as Agenda 21 on sus ainable cons uc ion [ 4 ] om 1999 o he mo e ecen p oposals o a “ci cula economy” [ 5 ]. These s a egies and he esea ch ha suppo s hem (e.g., [ 6 ]) indica e ha he building sec o plays an impo an ole in humani y’s ques o sus ainabili y. The eason is he massi e ene gy and esou ce consump ion connec ed o buildings, along wi h was e p oduc ion: buildings a e esponsible o app oxima ely 40% o o al ene gy consump ion and was e p oduc ion [ 7 ] and 25% o g eenhouse gas emissions [ 8 ]. Reducing hese nega i e impac s o he building indus y is he aim o egula ions like Eu opean di ec i e 2010/31/EU on he ene gy pe o mance o buildings (EPBD [ 9 ]). This ( ecen ly upda ed) di ec i e s a es ha all new buildings and majo eno a ion p ojec s in he EU should comply wi h “nea ly-Ze o Ene gy Building” (nZEB) s anda ds a e 2020. Li e a u e such as [ 10 ] sugges s ha he in oduc ion o nZEBs will esul in a Sus ainabili y 2018,10, 4212; doi:10.3390/su10114212 www.mdpi.com/jou nal/sus ainabili y Sus ainabili y 2018,10, 4212 2 o 16 massi e educ ion in ene gy consump ion (and a ela ed educ ion in en i onmen al impac ) in new buildings in compa ison wi h buildings comple ed o e he las ew decades. In he pas , he mos e icien way o imp o e he ene gy consump ion o buildings was o educe hei hea ing and en ila ion ene gy losses. This was achie ed h ough he addi ion o he mal insula ion o he building’s en elope and he ins alla ion o HVAC sys ems wi h hea eco e y [ 11 ]. This led o he de elopmen and p opaga ion o highly e icien “passi e” buildings [ 12 ]. Howe e , li e a u e such as [ 13 , 14 ] sugges s ha he po en ial o u he sa ings in con empo a y building designs is limi ed by inc easing in es men cos s and embodied ene gy (as well as o he en i onmen al impac s). The e o e, he indus y is looking o new solu ions ha will no only minimize ene gy losses, bu also u ilize he ene gy gains a ailable on-si e. Such solu ions include he in eg a ion o enewable ene gy sou ces (RES) like pho o ol aics [ 15 ] o sola he mal collec o s [ 16 ] o on-si e ene gy gene a ion. Bo h o he p e iously men ioned e e ences illus a e ha he ield o RES is al eady well es ablished in he li e a u e. S ill, he esea ch p esen ed in his pape ies o b ing a di e en pe spec i e on one o he mo e s aigh o wa d ways o using enewable na u al ene gy: he exploi a ion o sola ene gy gains wi h sola acades based on anspa en insula ion ma e ials (TIMs). The di ec u iliza ion o sola gains in buildings is no new. The sola wall p inciples ha o igina ed in he la e 19 h cen u y we e u he de eloped by F. T ombe in he 1960s [ 17 ]. The p inciple behind he sola wall (o he de i ed T ombe wall) is a he simple. I consis s o a massi e wall and a glass co e on he ex e io side o he wall. The ou e su ace o he wall is pain ed black in o de o abso b as much sola ene gy as possible. The ai gap be ween he glazing and he wall se es as a bu e and insula ion laye ha educes he hea losses o he s uc u e [ 18 ]. The sola wall concep has been s udied and de eloped wo ldwide o e he pas ew decades [ 19 ], when di e en s udies de eloped sola walls whe e TIMs eplaced he o iginal glazing elemen s [ 20 ]. The applica ion o TIMs had al eady p o en success ul in he case o sola he mal collec o s [ 21 ]. Thei in eg a ion in acade elemen s is s ill in de elopmen , e en hough comme cial p oduc s al eady exis [ 22 ]. The p esen ed s udy is pa o a esea ch p ojec ha s i es o add o he exis ing knowledge in his de eloping ield by e alua ing he e iciency o a ious TIMs in combina ion wi h o he no el elemen s and ma e ials such as low-emissi i y sola abso be s. The wo ks e e enced in he p e ious pa ag aph ypically analyze he he mal cha ac e is ics and ene gy balance o TIMs o sola walls. The e a e only a ew wo ks desc ibing he o e all en i onmen al impac s ela ed o hese s uc u es and ma e ials. Fo example, Dowson e al. [ 23 ] eleased a pape desc ibing he en i onmen al impac s ela ed o anspa en silica ae ogel insula ion. S azi e al. [ 24 ] p esen ed a s udy on he en i onmen al impac s o a a he adi ional sola wall concep . The applicabili y o he esul s o bo h s udies is limi ed as hey do no include compa isons wi h o he a ailable ma e ials. One o he ew s udies ha p o ide such a compa ison was eleased by de Ga cia e al. [25] . I shows ha (unde speci ied bounda y condi ions) he en ila ed sola açade hey es ed has a 7.5% lowe en i onmen al impac compa ed o a s anda d açade. The s udy p esen ed in his pape ollows de Ga cia’s example along wi h p e ious wo k by ˇ Cekon and S uhala [ 26 ], which e alua ed he pe o mance o wo TIM-based sola walls and a s anda d açade wi h mine al wool insula ion. The s udy p o ides an e alua ion o he en i onmen al impac s o 10 TIM-based açade assemblies and a compa ison wi h a e e ence açade wi h ex e nal he mal insula ion composi e sys em (ETICS). The e alua ion ocuses on he en i onmen al impac s o he acade assemblies du ing hei whole li e cycle: om ex ac ion o he aw ma e ials o he inal was e disposal. This should p o ide a complex unde s anding o he pe o mance o he concep . Fo his pu pose, he s udy also includes dynamic simula ions o he ene gy pe o mance based on egional clima e da a. The ene gy pe o mance is modelled o mul iple o ien a ions o he acades o he ca dinal poin s o p o ide u he insigh in o he e iciency o he desc ibed açade concep s. Sus ainabili y 2018,10, 4212 3 o 16 2. Me hodology and Ma e ials The goal o he p esen ed s udy is he e alua ion o he en i onmen al impac s o he TIM-based açade assemblies de ined in Sec ion 2.1. Li e-Cycle Assessmen (LCA) me hodology is applied o achie e his goal. LCA me hodology was concei ed in he 1960s in he USA and se e al Eu opean coun ies, [ 27 ]. Cu en ly i is well-es ablished in li e a u e (see e.g., [ 28 ]) as a me hod o complex mul i-c i e ia e alua ion o p oduc s. I s applica ions in building indus y a y om e alua ion o indi idual p oduc s o ma e ials o e alua ion o whole sys ems such as buildings o ci ies. I is especially use ul in compa a i e s udies, whe e i p o ides complex basis o he decision-making p ocess [29]. LCA p inciples a e in e na ionally s anda dized. The gene al amewo k is de ined in ISO 14040 [ 30 ]. This ISO s anda d is a he ague o he pu poses o he p esen ed s udy. The e o e, he bounda y condi ions and speci ica ions o building- ela ed LCAs desc ibed in Eu opean s anda ds EN 15804 [31] and EN 15978 [32] a e also applied in he p esen ed s udy. 2.1. Assessed Façade Assemblies A o al o 11 di e en açade assemblies a e e alua ed in he p esen ed s udy. The base o all he assemblies is a 200 mm hick conc e e wall wi h cemen -based plas e on he in e io su ace. Conc e e was selec ed in his s udy due o i s hea accumula ion po en ial and hea ans e p ope ies in o de o maximize he sola gains o assemblies wi h TIMs (see Figu e 1). Fi e di e en ypes o e ail-a ailable TIMs wi h di e en he mal and op ical p ope ies a e selec ed o e alua ion in he açade assemblies. Two ypes o e ail-a ailable sola abso be s a e selec ed o enhance he e iciency o an o e all he mal pe o mance: common black pain (a non-selec i e sola abso be , nSSA) and aluminum-based shee wi h low-emissi i y coa ing (a selec i e sola abso be , SSA). This decision is based on au ho s’ p e ious wo k [ 33 ] ha iden i ied up o 54% be e e iciency o SSA o e nSSA. The e alua ed açade assemblies a e de ined as ollows: •Assembly 1 is a e e ence assembly combining a conc e e wall wi h s anda d ETICS. The ETICS consis s o 220 mm expanded polys y ene (EPS), cemen -based adhesi e mo a and mine al ex e io plas e . The assembly ep esen s an en elope wall wi h a U- alue o 0.21 W · m −2· K −1 ha ul ils he high he mal p o ec ion le el o building. •Assembly 2 consis s o a conc e e wall, a nSSA, a 25 mm ai gap and a 40 mm TIM sys em made o honeycomb polyme hylme hac yla e PMMA (HP40; ci cula cells ho izon ally o ien ed, pe pendicula o he wall; see Figu e 1a) encased be ween glass panes. •Assembly 3 consis s o a conc e e wall, a nSSA, a 25 mm ai gap and a 10 mm polyca bona e TIM panel (PC10) wi h a single laye o e ically o ien ed squa e cells pa allel o he wall su ace (Figu e 1b). •Assembly 4 consis s o a conc e e wall, a nSSA, a 25 mm ai gap and a 20 mm polyca bona e TIM panel (PC20) wi h se en laye s o e ically o ien ed squa e cells pa allel o he wall su ace (Figu e 1c). •Assembly 5 consis s o a conc e e wall, a nSSA, a 25 mm ai gap and a 25 mm polyca bona e TIM panel (PC25) wi h wo laye s o e ically o ien ed iangula cells pa allel o he wall su ace (Figu e 1d). •Assembly 6 consis s o a conc e e wall, a nSSA, a 25 mm ai gap and a 32 mm polyca bona e TIM panel (PC32) wi h i e laye s o e ically o ien ed combined cells ( h ee laye s wi h squa e cells, wo laye s o iangula cells) pa allel o he wall su ace (Figu e 1e). •Assemblies 7 o 11 eplace he nSSA wi h SSA. O he wise he composi ion o hese assemblies is he same as he composi ion o assemblies 2 o 6. Sus ainabili y 2018,10, 4212 4 o 16 Sus ainabili y 2018, 10, x FOR PEER REVIEW 4 o 15 Figu e 1. Schema ic diag am o an e alua ed acade assembly wi h anspa en insula ion ma e ials (TIM) (le ) and he indi idual ypes o TIMs applied in he e alua ed açade assemblies ( igh ): (a) 40 mm honeycomb cells (HP40), (b) 10 mm single-laye squa e cells (PC10), (c) 20 mm se en-laye squa e cells (PC20), (d) 25 mm wo-laye iangula cells (PC25), (e) 32 mm i e-laye combined cells (PC32). 2.2. Bounda y Condi ions o he Assessmen The s udy models he whole li e cycle o açade assemblies om aw ma e ial ex ac ion up un il inal was e disposal as de ined by [32]. In pa icula , he s udy e alua es he en i onmen al impac s ela ed o 1 m2 o each assembly du ing an es ima ed se ice li e o 50 yea s. This se ice li e is a common building design alue in he Czech Republic. Fo he pu poses o he assessmen i is es ima ed ha only he conc e e load-bea ing pa o he wall would endu e he whole 50-yea se ice li e. I is assumed ha all o he o he ma e ials would ha e o be eplaced once (a e app ox. 25 yea s) due o hei lowe du abili y. This should mo e accu a ely model he eal use o açade assemblies. The li e cycle o he açade assemblies is di ided in o ou s ages acco ding o [32]: he P oduc s age, he Cons uc ion p ocess s age, he Use s age, and he End o li e s age. The e is a i h s age de ined in he s anda d ha deals wi h he euse and ecycling o ma e ials. Howe e , his s age is omi ed om he s udy o educe possible in o ma ion bias and a dis o ion o he esul s. The s anda d u he di ides he ou li e cycle s ages in o 16 modules (see Table 1). Table 1. Li e cycle o a building acco ding o EN 15978 [32]. S ages and modules conside ed in he p esen ed s udy a e highligh ed in bold ace and g ey backg ound colo . 1. A1 o A3 P oduc S age A1: Raw ma e ial supply D Bene i s and loads beyond he sys em bounda y (Reuse, Reco e y and Recycling po en ial) A2: T anspo A3: Manu ac u ing A4 o A5 Cons uc ion P oc. S age A4: T anspo A5: Cons uc ion/Ins alla ion p ocess B1 o B7 Use S age B1: Use B2: Main enance B3: Repai B4: Replacemen B5: Re u bishmen B6: Ope a ional ene gy use B7: Ope a ional wa e use C1 o C4 End o Li e S age C1: Decons uc ion/demoli ion C2: T anspo C3: Wa e p ocessing C4: Disposal Figu e 1. Schema ic diag am o an e alua ed acade assembly wi h anspa en insula ion ma e ials (TIM) (le ) and he indi idual ypes o TIMs applied in he e alua ed açade assemblies ( igh ): ( a ) 40 mm honeycomb cells (HP40), ( b ) 10 mm single-laye squa e cells (PC10), ( c ) 20 mm se en-laye squa e cells (PC20), ( d ) 25 mm wo-laye iangula cells (PC25), ( e ) 32 mm i e-laye combined cells (PC32). 2.2. Bounda y Condi ions o he Assessmen The s udy models he whole li e cycle o açade assemblies om aw ma e ial ex ac ion up un il inal was e disposal as de ined by [ 32 ]. In pa icula , he s udy e alua es he en i onmen al impac s ela ed o 1 m 2 o each assembly du ing an es ima ed se ice li e o 50 yea s. This se ice li e is a common building design alue in he Czech Republic. Fo he pu poses o he assessmen i is es ima ed ha only he conc e e load-bea ing pa o he wall would endu e he whole 50-yea se ice li e. I is assumed ha all o he o he ma e ials would ha e o be eplaced once (a e app ox. 25 yea s) due o hei lowe du abili y. This should mo e accu a ely model he eal use o açade assemblies. The li e cycle o he açade assemblies is di ided in o ou s ages acco ding o [ 32 ]: he P oduc s age, he Cons uc ion p ocess s age, he Use s age, and he End o li e s age. The e is a i h s age de ined in he s anda d ha deals wi h he euse and ecycling o ma e ials. Howe e , his age is omi ed om he s udy o educe possible in o ma ion bias and a dis o ion o he esul s. The s anda d u he di ides he ou li e cycle s ages in o 16 modules (see Table 1). Table 1. Li e cycle o a building acco ding o EN 15978 [ 32 ]. S ages and modules conside ed in he p esen ed s udy a e highligh ed in bold ace and g ey backg ound colo . A1: Raw ma e ial supply D Bene i s and loads beyond he sys em bounda y (Reuse, Reco e y and Recycling po en ial) A2: T anspo A1 o A3 P oduc S age A3: Manu ac u ing A4: T anspo A4 o A5 Cons uc ion P oc. S age A5: Cons uc ion/Ins alla ion p ocess B1: Use B2: Main enance B3: Repai B4: Replacemen B5: Re u bishmen B6: Ope a ional ene gy use B1 o B7 Use S age B7: Ope a ional wa e use C1: Decons uc ion/demoli ion C2: T anspo C3: Wa e p ocessing C1 o C4 End o Li e S age C4: Disposal Sus ainabili y 2018,10, 4212 5 o 16 Se e al o hese modules a e also omi ed in he s udy: Modules A5 (Cons uc ion/Ins alla ion p ocess) and C1 (Decons uc ion/Demoli ion) a e omi ed because i is expec ed ha en i onmen al impac s ela ed o hem would be negligible. Use o he açade assemblies should no cause any en i onmen al impac s and he e o e module B1 is omi ed. No epai o main enance is expec ed du ing he se ice li e o he açade assemblies. I is expec ed ha pa icula ma e ials will be eplaced a he end o hei espec i e se ice li es. The e o e, modules B2, B3 and B5 a e omi ed. No ope a ional wa e use and was e wa e p ocessing is expec ed and so modules B7 and C3 a e also omi ed. 2.3. Inpu Da a In en o y In o ma ion ega ding he ma e ials applied in indi idual assemblies is ob ained om labo a o y measu emen s o pu chased samples. Mo e in o ma ion abou he measu emen s can be ound in [ 34 ]. All he assemblies sha e he same base s uc u e made o 480 kg o conc e e o he pu poses o his s udy. The in e io o he s uc u e is co e ed wi h 16 kg o cemen plas e (see Figu e 1). The amoun s o ma e ials equi ed o he ex e io laye s o he açade assemblies (TIMs o ETICS) a e desc ibed in Table 2. Based on Czech s a is ical da a [ 35 ] i is expec ed ha a he end o he modelled se ice li e all ma e ials will be land illed. Table 2. Ma e ials conside ed in he e alua ed açade assemblies. EPS (ETICS) Cemen Mo a (ETICS) Mine al Plas e (ETICS) SSA nSSA Polyca bona e (TIM) Glass Co e (TIM) Assembly 1 6.60 kg 8.00 kg 16.00 kg — — — — Assembly 2 — — — — 0.15 kg 0.86 kg 26.00 kg Assembly 3 — — — — 0.15 kg 1.70 kg — Assembly 4 — — — — 0.15 kg 3.00 kg — Assembly 5 — — — — 0.15 kg 3.40 kg — Assembly 6 — — — — 0.15 kg 3.60 kg — Assembly 7 — — — 0.81 kg — 0.86 kg 26.00 kg Assembly 8 — — — 0.81 kg — 1.70 kg — Assembly 9 — — — 0.81 kg — 3.00 kg — Assembly 10 — — — 0.81 kg — 3.40 kg — Assembly 11 — — — 0.81 kg — 3.60 kg — The anspo o ma e ials (in modules A2, A4, B4 and C2) is ano he impo an pa o building- ela ed LCA. T anspo dis ances be ween a hypo he ical building si e in he ci y o B no (Czech Republic) and he nea es p oduc ion (was e managemen ) acili ies a e conside ed in his s udy o ep esen a eal-li e anspo scena io. The anspo dis ances be ween he pe inen p oduc ion acili ies and B no a e: 591 km o he HP40 TIM; 536 km o he SSA; 324 km o he PC10, PC20, PC25 and PC30 TIMs; 160 km o nSSA; 32 km o he plas e s and mo a s; 15 km o he EPS; 5 km o he conc e e. The nea es land ill is loca ed 13 km om he building si e. Ene gy consump ion is he mos impo an pa o he p esen ed LCA as i has a majo impac on he o al esul s (see Sec ion 3.2). Ene gy consumed du ing he ope a ion o he e alua ed açade assemblies can be di ided in o wo pa s: (summe ) cooling ene gy and (win e ) hea ing ene gy. The p esen ed s udy only includes he hea ing ene gy consump ion (see Table 3) necessa y o main ain an in e io empe a u e o 20 ◦ C behind he e alua ed açade assemblies. The eason is ha p e ious esea ch [ 26 ] has al eady indica ed he p oblem o o e hea ing in summe . This p oblem equi es u he echnical solu ions, such as shading o he applica ion o phase-change ma e ials [ 25 ]. Such addi ions a e conside ed ou side he scope o he p esen ed s udy, which ocuses solely on he açade assemblies desc ibed in Sec ion 2.1. I should be no ed ha elec ici y is conside ed o be he ene gy sou ce in he calcula ions. Sus ainabili y 2018,10, 4212 6 o 16 Table 3. The annual hea ing ene gy consump ion o he e alua ed açade assemblies. Th ee scena ios wi h di e en açade elemen o ien a ions a e conside ed. Ene gy Consump ion [kWh·m−2]Sou h (180◦) Eas (90◦) No h-Eas (15◦) Assembly 1 44.3 46.8 48.3 Assembly 2 5.1 6.8 8.1 Assembly 3 31.1 41.5 47.9 Assembly 4 17.5 24.1 28.3 Assembly 5 18.0 24.8 29.1 Assembly 6 13.9 19.3 22.9 Assembly 7 3.0 4.0 4.7 Assembly 8 18.1 24.1 28.0 Assembly 9 10.5 14.2 16.8 Assembly 10 10.8 14.6 17.3 Assembly 11 8.5 11.6 13.8 2.3.1. Calcula ion o Ene gy Consump ion The basis o he e alua ion o en i onmen al impac s ela ed o ene gy consump ion is he dynamic nume ical modelling o he ene gy pe o mance o he açade assemblies. Dynamic modelling was selec ed as li e a u e such as [ 36 ] sugges s ha i should p o ide he mos accu a e da a o LCA. This ype o modelling conside s he he mal and spec al pa ame e s o he e alua ed ma e ials ha we e ob ained in he cou se o esea ch o p e ious wo ks ([ 34 , 37 ]) as well as a ying ex e io condi ions. A summa y o he ma e ial pa ame e s is in Table 4. The nume ical algo i hm applied o he modelling is based on one-dimensional ini e elemen s. The ime disc e iza ion o he hea ans e p oblem uses a ully implici scheme. The ansi ion o hea in he solid non- anspa en laye s conside s conduc i e hea ans e desc ibed by he mal conduc i i y, hea capaci y, and densi y. Fu he in o ma ion abou hea ans e modelling can be ound in li e a u e such as [ 38 ] o [ 39 ]. T anspa en ma e ials like polyca bona e panels a e modelled as single one-dimensional ini e elemen s wi h equi alen hea ans e p ope ies and anspa ency o sola adia ion. This means ha sola adia ion pene a es he ma e ial o e a pe iod o ime p opo ional o i s anspa ency. Ai gaps a e also modelled as single ini e elemen s acco ding o he me hod s a ed in ISO 6946 [ 40 ] wi h equi alen he mal esis ance ha akes in o accoun adia i e hea ans e a ec ed by he emissi i y o su aces and a con ec i e componen in luenced by he hickness o he ai laye . A schema ic diag am illus a ing he nume ical model is in Figu e 2. The bounda y condi ions u ilized o he nume ical modelling o he ene gy pe o mance o açade assemblies a e as ollows: The hea ans e coe icien equals 25 W · m −2· K −1 on he in e io su ace and 7 W · m −2· K −1 on he ex e io su ace o he modelled açade assemblies. These alues a e based on [ 41 ]. The ex e io su ace is also exposed o sola adia ion, which is conside ed o be pe pendicula o he su ace o he pu poses o he modelling. The inciden sola adia ion includes p ojec ed di ec sola adia ion, di used sola adia ion, and e lec ed sola adia ion om he g ound, which a e based on ela ions om he li e a u e [ 41 ]. The o al sola ene gy gains depend on he o ien a ion o he açade assemblies o he ca dinal di ec ions, he sola abso p ion coe icien o pa icula ma e ials and ime (based on e e ence clima e da a). All possible o ien a ions o he ca dinal poin s we e conside ed du ing he calcula ions (see Figu e 3). This s udy p esen s h ee ene gy demand scena ios (see Table 3): a sou hwa d o ien a ion (180 ◦ clockwise om no h), an eas wa d o ien a ion (90 ◦ clockwise om no h) and a no h-eas wa d o ien a ion (30 ◦ clockwise om no h). The sou hwa d o ien a ion ep esen s he s a e wi h maximum sola gains. The e o e, he hea ing ene gy consump ion o he assemblies wi h TIM is he lowes . The eas wa d and no h-eas wa d o ien a ions a e included in his s udy o e alua e he impac o educed sola gains on he esul s. Wes -o ien ed acades had lowe ene gy consump ion in he calcula ions and so a e no included in he p esen ed s udy. The clima e da a conside ed in he calcula ions a e based on a e e ence es yea o B a isla a “SVK_B a isla a.118160_IWEC” in he hou ime egime [ 42 ]. This was selec ed Sus ainabili y 2018,10, 4212 7 o 16 as B a isla a (Slo akia) is geog aphically he closes ci y o he hypo he ical cons uc ion si e in B no (Czechia), which has he necessa y clima e da a. The ime s ep used o he dynamic modelling is 600 s and in e media e alues a e linea ly in e pola ed. A 20 ◦ C in e io empe a u e is conside ed o he pu poses o he modelling. Table 4. Ma e ials conside ed in he e alua ed açade assemblies and hei physical pa ame e s. *: equi alen alue. **: measu ed alue acco ding o [34,37]. Thickness [mm] Numbe o Fini e Elemen s Densi y [kg·m−3] The mal Conduc i i y [W·m−1·K−1] The mal Capaci y [kJ·kg−1·K−1] Sola Abso bance The mal Emissi i y Sola T ansmi ance ** Plas e 0.01 2 1600 0.75 840 0.6 0.93 — Conc e e 0.02 10 2400 1.47 1000 1 0.93 — Polys y ene 0.22/0.05 10 15 0.040 * 1200 1 0.90 — PC10 0.010 1 165 * 0.065 * 1000 0.2 0.84 0.82 PC20 0.020 1 144.9 * 0.051 * 1000 0.2 0.84 0.62 PC25 0.025 1 135.5 * 0.066 * 1000 0.2 0.84 0.63 PC32 0.032 1 110.8 * 0.059 * 1000 0.2 0.84 0.53 TIM 0.040 1 1000 0.040 1000 0.2 0.84 0.58 nSSA — — — — — 0.95 0.9 — SSA — — — — — 0.95 0.1 — Sus ainabili y 2018, 10, x FOR PEER REVIEW 7 o 15 si e in B no (Czechia), which has he necessa y clima e da a. The ime s ep used o he dynamic modelling is 600 s and in e media e alues a e linea ly in e pola ed. A 20 °C in e io empe a u e is conside ed o he pu poses o he modelling. Table 4. Ma e ials conside ed in he e alua ed açade assemblies and hei physical pa ame e s. *: equi alen alue. **: measu ed alue acco ding o [34,37]. Thickness [mm] Numbe o Fini e Elemen s Densi y [kg·m−3] The mal Conduc i i y [W·m−1·K−1] The mal Capaci y [kJ·kg−1·K−1] Sola Abso bance The mal Emissi i y Sola T ansmi ance ** Plas e 0.01 2 1600 0.75 840 0.6 0.93 --- Conc e e 0.02 10 2400 1.47 1000 1 0.93 --- Polys y ene 0.22/0.05 10 15 0.040 * 1200 1 0.90 --- PC10 0.010 1 165 * 0.065 * 1000 0.2 0.84 0.82 PC20 0.020 1 144.9 * 0.051 * 1000 0.2 0.84 0.62 PC25 0.025 1 135.5 * 0.066 * 1000 0.2 0.84 0.63 PC32 0.032 1 110.8 * 0.059 * 1000 0.2 0.84 0.53 TIM 0.040 1 1000 0.040 1000 0.2 0.84 0.58 nSSA --- --- --- --- --- 0.95 0.9 --- SSA --- --- --- --- --- 0.95 0.1 --- Figu e 2. Calcula ion model based on he ini e elemen me hod o : (a) an opaque s uc u e; (b) a s uc u e wi h a anspa en elemen on he ex e io side. Figu e 3. Sola adia ion model based on he ini e elemen me hod; calcula ed educ ion ac o o he azimu h o he s uc u e and ime o yea : (a) o July; (b) o Janua y. 2.3.2. LCA Calcula ion P ocedu e and Tools The LCA was pe o med in GaBi so wa e equipped wi h he ecoin en 2.0 [43] da abase. No da a desc ibing he pe o mance and en i onmen al impac s o he ma e ials we e a ailable a he ime o he s udy. The e o e he s udy is based on gene ic ecoin en da ase s. The a ailable da ase s do no desc ibe all o he p oduc s and p ocesses necessa y o he assessmen , which esul s in se e al simpli ica ions in he LCA models: Figu e 2. Calcula ion model based on he ini e elemen me hod o : ( a ) an opaque s uc u e; (b) a s uc u e wi h a anspa en elemen on he ex e io side. Sus ainabili y 2018, 10, x FOR PEER REVIEW 7 o 15 si e in B no (Czechia), which has he necessa y clima e da a. The ime s ep used o he dynamic modelling is 600 s and in e media e alues a e linea ly in e pola ed. A 20 °C in e io empe a u e is conside ed o he pu poses o he modelling. Table 4. Ma e ials conside ed in he e alua ed açade assemblies and hei physical pa ame e s. *: equi alen alue. **: measu ed alue acco ding o [34,37]. Thickness [mm] Numbe o Fini e Elemen s Densi y [kg·m−3] The mal Conduc i i y [W·m−1·K−1] The mal Capaci y [kJ·kg−1·K−1] Sola Abso bance The mal Emissi i y Sola T ansmi ance ** Plas e 0.01 2 1600 0.75 840 0.6 0.93 --- Conc e e 0.02 10 2400 1.47 1000 1 0.93 --- Polys y ene 0.22/0.05 10 15 0.040 * 1200 1 0.90 --- PC10 0.010 1 165 * 0.065 * 1000 0.2 0.84 0.82 PC20 0.020 1 144.9 * 0.051 * 1000 0.2 0.84 0.62 PC25 0.025 1 135.5 * 0.066 * 1000 0.2 0.84 0.63 PC32 0.032 1 110.8 * 0.059 * 1000 0.2 0.84 0.53 TIM 0.040 1 1000 0.040 1000 0.2 0.84 0.58 nSSA --- --- --- --- --- 0.95 0.9 --- SSA --- --- --- --- --- 0.95 0.1 --- Figu e 2. Calcula ion model based on he ini e elemen me hod o : (a) an opaque s uc u e; (b) a s uc u e wi h a anspa en elemen on he ex e io side. Figu e 3. Sola adia ion model based on he ini e elemen me hod; calcula ed educ ion ac o o he azimu h o he s uc u e and ime o yea : (a) o July; (b) o Janua y. 2.3.2. LCA Calcula ion P ocedu e and Tools The LCA was pe o med in GaBi so wa e equipped wi h he ecoin en 2.0 [43] da abase. No da a desc ibing he pe o mance and en i onmen al impac s o he ma e ials we e a ailable a he ime o he s udy. The e o e he s udy is based on gene ic ecoin en da ase s. The a ailable da ase s do no desc ibe all o he p oduc s and p ocesses necessa y o he assessmen , which esul s in se e al simpli ica ions in he LCA models: Figu e 3. Sola adia ion model based on he ini e elemen me hod; calcula ed educ ion ac o o he azimu h o he s uc u e and ime o yea : (a) o July; (b) o Janua y. 2.3.2. LCA Calcula ion P ocedu e and Tools The LCA was pe o med in GaBi so wa e equipped wi h he ecoin en 2.0 [ 43 ] da abase. No da a desc ibing he pe o mance and en i onmen al impac s o he ma e ials we e a ailable a he ime o he s udy. The e o e he s udy is based on gene ic ecoin en da ase s. The a ailable da ase s do no desc ibe all o he p oduc s and p ocesses necessa y o he assessmen , which esul s in se e al simpli ica ions in he LCA models: • The e is no single da ase ep esen ing he TIMs. The PC10, PC20, PC25 and PC30 TIMs a e ep esen ed by a combina ion o da ase s, hese being RER: polyca bona e, a plan (ma e ial) and Sus ainabili y 2018,10, 4212 8 o 16 RER: ex usion, plas ic ilm (p ocessing). The HP40 TIM includes bo h hese da ase s plus he da ase RER: la glass, uncoa ed, a plan ep esen ing he glass casing. • The e is also no single da ase ep esen ing he selec i e sola abso be . I is modelled as a combina ion o da ase s, hese being RER: aluminum, p ima y, a plan (base ma e ial), RER: shee olling, aluminum (p ocessing) and SK: selec i e coa ing, aluminum shee , nickel pigmen ed aluminum oxide (coa ing). • The anspo o aw ma e ials and incomple e p oduc s du ing he P oduc s age (especially module A2) is included in indi idual ecoin en da ase s. The A4 and C2 (pa ially also B4) modules desc ibe he anspo o inal p oduc s and was es espec i ely. Fo he pu poses o he assessmen i is assumed ha he ma e ials and was es a e anspo ed by oad wi h a uck o lo y. This is ep esen ed by he da ase RER: anspo , lo y 3.5-16 , lee a e age. • Elec ic ene gy in p ocess CZ: Elec ici y—low ol age, a g id ep esen s he ene gy consumed o co e hea losses o o e hea ing h ough he e alua ed açade assemblies. No da ase ep esen ing HVAC equipmen is included in he assessmen . The en i onmen al impac s ela ed o he e alua ed açade assemblies a e calcula ed using he CML2001 me hod ( e sion No . 10). This me hod was de eloped by he Ins i u e o En i onmen al Sciences, Uni e si y o Leu en in he Ne he lands [ 29 ]. I includes 12 impac ca ego ies: Abio ic Deple ion Po en ial o Elemen s (ADP-el), Abio ic Deple ion Po en ial o Fossil Fuels (ADP- ), Acidi ica ion Po en ial (AP), Eu ophica ion Po en ial (EP), F eshwa e Aqua ic Eco oxici y Po en ial (FAETP), Global Wa ming Po en ial (GWP), Global Wa ming Po en ial Excluding Biogenic Ca bon (GWP-ex), Human Toxici y Po en ial (HTP), Ma ine Aqua ic Eco oxici y Po en ial (MAETP), Ozone Laye Deple ion Po en ial (ODP), Pho ochemical Ozone C ea ion Po en ial (POCP), and Te es ial Eco oxici y Po en ial (TETP). No maliza ion o he indi idual esul s is also applied ( e sion No . 10, EU25+3) o enable he agg ega ing o indi idual impac ca ego y esul s and inc ease he comp ehensi eness o he s udy. 3. Resul s and Discussion The p esen a ion o he LCA esul s is di ided in o wo pa s o inc eased cla i y. This is due o he ac ha he majo i y o en i onmen al impac s a e (acco ding o he pe o med calcula ions) ela ed o he elec ical ene gy necessa y o co e hea losses. Howe e , li e a u e such as [ 44 ] o [ 45 ] indica es he inc easing impo ance o en i onmen al impac s ela ed o ma e ials (embedded o embodied en i onmen al impac s). The e o e, Sec ion 3.1 ocuses on “embodied” en i onmen al impac s ela ed o applied ma e ials, hei anspo , eplacemen , and was e p ocessing (modules A1–A4, B4, C2 and C4, acco ding o [ 32 ]). O e all en i onmen al impac s, including ene gy consump ion (module B6 acco ding o [32]), a e desc ibed in Sec ion 3.2. 3.1. E alua ion o Ma e ial-Rela ed En i onmen al Impac s Table 5and Figu e 4show embodied en i onmen al impac s ela ed o he p oduc ion o ma e ials (modules A1–A3 acco ding o [ 32 ]) necessa y o he cons uc ion o he e alua ed açade assemblies. Table 5shows nume ical esul s in all 12 impac ca ego ies. These esul s indica e ha Assembly 3 has he ewes embodied en i onmen al impac s connec ed wi h he p oduc ion o necessa y ma e ials in modules A1–A3. On he o he hand, he iden i ica ion om Table 5o he assembly wi h he highes amoun o embodied en i onmen al impac s in hese modules is impossible as a ious assemblies ha e he wo s esul s in indi idual impac ca ego ies. Assembly 7 has he highes impac s in six impac ca ego ies. Re e ence Assembly 1 and Assembly 11 bo h ha e he highes embodied impac s in h ee ca ego ies. O e all he di e ence be ween he lowes and highes embodied en i onmen al impac s in he modules a ies be ween 29% (GWP and GWP-ex) and 89% (MAETP) in indi idual ca ego ies. The easons o hese di e ences a e isible in Figu e 4, which shows s acked no malized en i onmen al impac s o modules A1–A3 o he e alua ed assemblies. Sus ainabili y 2018,10, 4212 9 o 16 Table 5. En i onmen al impac s ela ed o he p oduc ion o ma e ials included in he assessed açade assemblies (modules A1–A3 acco ding o [32]). Assembly 1 Assembly 2 Assembly 3 Assembly 4 Assembly 5 Assembly 6 Assembly 7 Assembly 8 Assembly 9 Assembly 10 Assembly 11 ADP-el [kg Sb-Equi .] 6.5 ×10−42.2 ×10−41.2 ×10−41.4 ×10−41.5 ×10−41.5 ×10−42.7 ×10−41.8 ×10−42.0 ×10−42.0 ×10−42.0 ×10−4 ADP- [MJ] 1.1 8.0 ×10−16.1 ×10−17.3 ×10−17.7 ×10−17.9 ×10−11.1 8.8 ×10−11.0 1.0 1.1 AP [kg SO2-Equi .] 2.7 ×10−13.8 ×10−11.7 ×10−12.1 ×10−12.2 ×10−12.3 ×10−14.9 ×10−12.8 ×10−13.2 ×10−13.3 ×10−13.4 ×10−1 EP [kg Phospha e-Equi .] 5.0 ×10−25.4 ×10−23.6 ×10−23.9 ×10−24.0 ×10−24.1 ×10−26.4 ×10−24.6 ×10−24.9 ×10−25.0 ×10−25.1 ×10−2 FAETP [kg DCB-Equi .] 4.7 3.4 2.8 3.0 3.1 3.1 1.0 ×10 9.7 9.9 1.0 ×10 1.0 ×10 GWP [kg CO2-Equi .] 1.0 ×1028.5 ×10 7.7 ×10 8.8 ×10 9.1 ×10 9.3 ×10 1.0 ×1029.3 ×10 1.0 ×1021.1 ×1021.1 ×102 GWP-ex [kg CO2-Equi .] 9.9 ×10 8.4 ×10 7.6 ×10 8.7 ×10 9.0 ×10 9.2 ×10 9.9 ×10 9.2 ×10 1.0 ×1021.1 ×1021.1 ×102 HTP [kg DCB-Equi .] 1.5 ×10 1.3 ×10 8.5 9.2 9.4 9.5 1.9 ×10 1.5 ×10 1.6 ×10 1.6 ×10 1.6 ×10 MAETP [kg DCB-Equi .] 1.3 ×1043.3 ×1047.2 ×1038.1 ×1038.4 ×1038.5 ×1036.5 ×1043.9 ×1044.0 ×1044.0 ×1044.0 ×104 ODP [kg R11-Equi .] 5.4 ×10−65.5 ×10−63.2 ×10−63.2 ×10−63.2 ×10−63.2 ×10−66.6 ×10−64.3 ×10−64.4 ×10−64.4 ×10−64.4 ×10−6 POCP [kg E hene-Equi .] 8.1 ×10−23.3 ×10−22.2 ×10−22.7 ×10−22.8 ×10−22.9 ×10−24.1 ×10−23.1 ×10−23.5 ×10−23.6 ×10−23.7 ×10−2 TETP [kg DCB-Equi .] 3.7 ×10−12.9 ×10−12.6 ×10−13.0 ×10−13.2 ×10−13.2 ×10−14.4 ×10−14.0 ×10−14.4 ×10−14.6 ×10−14.6 ×10−1 Sus ainabili y 2018,10, 4212 16 o 16 39. Lewis, R.W.; Ni hia asu, P.; See ha amu, K.N. Fundamen als o The Fini e Elemen Me hod o Hea and Fluid Flow; John Wiley & Sons, L d.: Chiches e , UK, 2004; ISBN 0-470-84788-3. 40. ISO. Building Componen s and Building Elemen s—The mal Resis ance and The mal T ansmi ance—Calcula ion Me hod; ISO 6946; In e na ional O ganiza ion o S anda diza ion (ISO): Gene a, Swi ze land, 2017; p. 40. 41. Hens, H. Applied Building Physics; Wilhelm E ns & Sohn: Be lin, Ge many, 2011; ISBN 978-3-433-02962-6. 42. Ene gyPlus. Wea he Da a by Loca ion. A ailable online: h ps://ene gyplus.ne /wea he -loca ion/eu ope_ wmo_ egion_6/SVK//SVK_B a isla a.118160_IWEC (accessed on 14 No embe 2018). 43. F ischknech , R.; Jungblu h, N.; Al haus, H.-J.; Doka, G.; Dones, R.; Hischie , R.; Hellweg, S.; Nemecek, T.; Rebi ze , G.; Spielmann, M. O e iew and Me hodology. Final Repo Ecoin en Da a 2.0; Swiss Cen e o Li e Cycle In en o ies: Dübendo , Swi ze land, 2007; p. 77. 44. Du il, Y.; Rousse, D.; Quesada, G. Sus ainable Building: An e e e ol ing Ta ge . Sus ainabili y 2011 , 3, 443–464. [C ossRe ] 45. Roh, S.; Tae, S.; Suk, S.J.; Fo d, G. E alua ing he embodied en i onmen al impac s o majo building asks and ma e ials o apa men buildings in Ko ea. Renew. Sus ain. Ene gy Re . 2017,73, 135–144. [C ossRe ] © 2018 by he au ho s. Licensee MDPI, Basel, Swi ze land. This a icle is an open access a icle dis ibu ed unde he e ms and condi ions o he C ea i e Commons A ibu ion (CC BY) license (h p://c ea i ecommons.o g/licenses/by/4.0/).