Solutions to Improve the Thermal Protection of the Administrative Building

Transcription

1 Solutions to Impove the Themal Potection of the Administative Building Valeiya Kostenko 1,*, Nailya Gafiyatullina 1, Gafu Zulkaneev 1, Aleksand Goshkov 1, Maina Petichenko 1 and Saa Movafagh 2 1 Pete the Geat St. Petesbug Polytechnic Univesity, Politechnicheskaya st. 29, St. Petesbug, Russia 2 Univesity of Guilan, Khalij Fas highway, Ghazvin oad, Rasht, Ian Abstact. At the end of the 90s, with the intoduction of changes in the egulatoy documents of the Russian Fedeation 3 to SNiP II-3-79*, egulatoy equiements fo themal potection of buildings wee evised towads incease. Fo this eason, the buildings built till 2000 don't confom to moden equiements. The actual solution of this poblem is to cay out woks on enovation of facades of the existing buildings with the use of innovative mateials. As object of eseach one of educational cases of Pete the Geat St. Petesbug Polytechnic Univesity has been chosen, whee by pactical consideation the size of the actual themal esistance of extenal walls has been detemined by heat flux mete, the numeical value of which was significantly lowe than the standad values. Based on the obtained data two moden ways of themal insulation of facades (Ventilated Façade System (VFS) and Extenal Themal Insulation Composite System (ETICS)) have been analyzed, the assessment of enegy saving potential and the discounted payback peiod of the investments diected to waming of facades has been made. 1 Intoduction About 95% of the buildings of the total amount existing housing stock in Russia do not coespond to moden equiements fo themal insulation, i.e. they ae obsolete. The physical state of the building facades is also often faulty. In this egad, measues fo heat insulation of extenal building envelope should be ecognized as easonable. In addition to impoving the appeaance of buildings, aise themal insulation of the building envelope leads to decease of tansmission heat losses [1-6]. The lowe the heat loss in the building, the lowe the amount of themal enegy is equied to bing to the building fom a heat supply souce to compensate fo tansmission losses. Thus, the themal insulation leads to decease enegy consumption in the building and consequently to eduction of payments fo heating [3-6]. One of the impotant chaacteistics of themal insulation pefomance of the building envelope is the esistance to heat tansfe. The methods of detemining it based on * Coesponding autho: kostenkolea@gmail.com The Authos, published by EDP Sciences. This is an open access aticle distibuted unde the tems of the Ceative Commons Attibution License 4.0 (

2 laboatoy tests of mateial samples o fagments of building stuctues in climatic chambes, o eseaches ae conducted diectly in a natual extenal envionment. The latte method is moe suitable because it does not equie destuction of the stuctue and enables to detemine the chaacteistics of the actual design and not the model. The test allows to quantify the themotechnical chaacteistics of the building envelope (heat tansfe esistance, themal conductivity, themal flux density) and to check thei compliance with the egulatoy equiements established in accodance with the ules [10], to detemine the eal heat loss though exteio walls. The aim of the aticle is a quantitative analysis of the themotechnical chaacteistics of the building envelope, which ae caied out by compaing the actual heat tansfe esistance values with nomative data, offe methods of the building envelope insulation with thei technical and economic compaison, a choice of the most effective technical solutions. 2 Initial design data The building was designed in 1970 that is the educed value of the heat tansfe esistance of the building envelope R 0 was detemined accoding to the standad [7] by climatic paametes of Leningad and was equal 0.98 m 2 C/W. 3 The esults of field obsevations Expeimental eseach of exteio walls R-value of Pete the Geat St. Petesbug Polytechnic Univesity Gidokopus-2 (Fig. 1) was caied out using ITP-MG4.03/5(I) "POTOK" heat flux density mete. The test was conducted fom 15 to 20 Januay Duing this peiod, an outdoo ai tempeatue vaied in the ange fom minus 23 C to minus 2 C, an inne wall suface tempeatue fom 14 C to 16 C. The building walls ae made of solid bick 510 mm thick with ceamic plating. Fig. 1. Pete the Geat St. Petesbug Polytechnic Univesity Gidokopus-2. Fig. 2 is a gaph showing changes in heat fluxes thoughout the entie study peiod. The actual heat tansfe esistance has been calculated in the aea of heat fluxes stationay themal conditions anging fom 30.6 W/m 2 to W/m 2. Futhe, the test was discontinued, since a shap waming began fom 19 Januay 2016, the outside ai tempeatue became highe than minus 10 C. 2

3 Fig. 2. Gaph of heat flux changes. Fig. 3 is a gaph of tempeatue changes on the wall sufaces indoos (τ 1 ) and outdoos (τ 2 ). Fig. 3. Gaph of tempeatue changes: τ 1 the inne wall suface tempeatue, τ 2 the oute wall suface tempeatue, τ 1 -τ 2 tempeatue diffeence. In accoding with the standad [9] the building envelope R-value R k is defined as the diffeence between the aveage tempeatues of the building envelope inne and oute sufaces duing the test peiod to the aveage heat flux density passing though the enclosue. Accoding to what it is equal to 0.73 m 2 C/W. Themal esistance calculated by taking into account additional factos, equal to 0.89 m 2 C/W. Fo the pupose of compaison of the themal conductivity actual values of the mateials used in constuction, with poject values, masony U-value was detemined: λ k = 0.7 W/m C. 3

4 4 Cuent egulatoy equiements Accoding to the equiements [10, 12] in St. Petesbug the basic value of the educed total themal esistance of the building envelope is R 2,5m 2 0 C/W, the nomalized value of the educed total themal esistance of the building envelope is R 1,57m 2 C/W. nom 0 5 Compaative analysis of the façade solutions Compae the walls R-values when waming by ETICS (Extenal Themal Insulation Composite System) R ETICS, and VFS (Ventilated Façade System) R VFS. (Fig. 4) Fig. 4. Schematic epesentation of the consideed extenal wall constuction: a with mineal wool themal insulation with plaste finish; b with a ventilated suspended facade system. Tempeatue analyze of the wall with mineal wool themal insulation based on basalt fibe (ρ = 100 kg/m 3 semiigid) with thin laye plaste finish (Fig. 4a) [13]: 1 cement-lime plaste: λ 1 = 0.87 W/m C, δ 1 = 0.01 m; 2 bick masony: λ 2 = 0.7 W/m C, δ 2 = 0.51 m; 3 mineal wool slab: λ 3 = W/m C, δ 3 = 0.1 m; 4 potective laye fom thin laye plaste: λ 4 = 0.87 W/m C, δ 4 = m. Rated themal esistance was detemined accoding to the standad [13], taking into account the stuctual featues of the facade systems. The ETICS R-value is equal to R ETICS = 2.7 m 2 C/W > 1.57 m 2 C/W. 4

5 Tempeatue analyze of the wall with suspended facade system with ventilated ai-space and with mineal wool themal insulation based on basalt (ρ = 100 kg/m 3 semiigid) (Fig. 4b): 1 cement-lime plaste: λ 1 = 0.87 W/m C, δ 1 = 0.01 m; 2 bick masony: λ 2 = 0.7 W/m C, δ 2 = 0.51 m; 3 mineal wool slab: λ 3 = W/m C, δ 3 = 0.1 m; 4 ai gap: R a.g. = 0, because ai-space is not closed; 5 ceamic ganite tile (heat-insulating quality of decoative sceen is not taken into account). The VFS R-value is equal to R VFS = 2.06 m 2 C/W > 1.57 m 2 C/W. 6 Detemination of tansmission heat losses The calculation of tansmission heat losses duing the heating peiod Q be is pefomed by the oveall heat tansfe equation. The value of heat loss duing the heating peiod: actual: Q be = Gcal/yea; ETICS: Q be ETICS = Gcal/yea; VFS: Q be VFS = 237 Gcal/yea. Thus, the heat enegy savings will be: ΔQ ETICS = Gcal/yea afte ETICS application, ΔQ VFS = Gcal/yea afte VFS application. Methods of calculating capital costs fo additional insulation, opeating costs befoe and afte themal insulation, as well as the payback peiod of enegy-saving measues ae descibed in detail in the woks [15-19]. Calculate the economic effect in elation to the two selected vaiants of facades heat insulation: ΔE ETICS = ub/yea; ΔE VFS = ub/yea. Capital expenditue on insulation of extenal walls of the existing building: ΔC ETICS = ub. ΔC VFS = ub. Simple payback peiod of insulation the oute wall of the existing building insulation with a thickness of 100 mm is: T ETICS = 28.3 yeas; T VFS = 92.9 yeas. Note that the calculated payback peiod was obtained without taking into account: taiffs aising fo themal enegy; inteest on the loan (in the case of the application of loan funds to cay out events fo the insulation of building extenal walls); discounting of achieved futue cash flows as a esult of implementation of enegysaving measues unde consideation and of educe the heat enegy loss fo heating. Fo this eason, the calculated values of the pojected payback peiod of the investment can be egaded only as estimates. Heat taiffs incease annually. This means that the annual cost savings will incease with each subsequent yea (heating peiod). Taking into account the above-mentioned factos, the pojected payback peiod of investment in additional facades insulation is detemined by a logaithmic equation [15-20]. Accoding to the equation the payback peiod of enegy-saving measues was calculated taking into account the total capital expenditue fo its implementation, the ising cost of taiffs fo themal enegy (), discounting futue cash flows (i), achieved by cost-cutting as a esult of the implementation of enegy-saving measues. 5

6 Values and i ae fickle and change evey yea. Possible options fo payback, depending on the changes of the vaiables ae pesented in Table 1 fo ETICS and in Table 2 fo VFS. Table 1. Coelation analysis esults of the payback peiod of ETICS taking into account the changes in the aveage annual ate of the ising cost of taiffs fo themal enegy () and in the futue cash flows discount facto on the key ate of the Cental Bank of the Russian Fedeation (i). i Table 2. Coelation analysis esults of the payback peiod of VFS taking into account the changes in the aveage annual ate of the ising cost of taiffs fo themal enegy () and in the futue cash flows discount facto on the key ate of the Cental Bank of the Russian Fedeation (i). i To solve the poblem of estimating the pojected payback peiod of investment in enegy efficiency magnitude was adopted of the aveage ove the last 5 yeas (16%), and the value i was fo 2016 (11%). In this case the payback peiod of investment will be: 6

7 T ETICS = 18.7 yeas; T VFS = 37.4 yeas. On esults of calculations in Tables 1 and 2, it can be assessed how the investment payback peiod vaies depending on the diffeentiation of the coefficient the aveage annual taiff aising fo themal enegy () and the discount ate of futue cash flows on the key ate of the Cental Bank of the Russian Fedeation (i). It can also be concluded that the facade enovation of obsolete buildings is possible, if i, and is not justified, when < i. 7 Results Accoding to the expeience esults: themotechnical chaacteistics and envelopes of the building wee evaluated with 2 egulatoy equiements [10]. Requied design heat tansfe esistance is R 0 2,5m C/W, actual heat tansfe esistance is R 0 = 0.89 m 2 C/W; options fo enovation of facades ae consideed in the most widespead ways. Heat tansfe esistance values of facade systems wee founded: R 0 ETICS = 2.7 m 2 C/W at ETICS, R 0 VFS = 2.06 m 2 C/W at VFS; tansmission heat losses fo heating wee defined: actual Q be = Gcal/yea; with ETICS Q be ETICS = Gcal/yea; with VFS Q be VFS = 237 Gcal/yea; capital costs fo pefomance of wok upon insulation of administative building facades and investment payback peiod fo both insulation methods, taking into account the aveage annual taiff aising fo themal enegy and discounting futue cash flows on the key ate of the Cental Bank of the Russian Fedeation wee calculated: these ae ΔC = ,80 ub, Т ETICS = 18.7 yeas at ETICS; these ae ΔC = ,0 ub, Т VFS = 37.4 yeas at VFS. 8 Conclusion By esults of expeience it was evealed that the actual condition of extenal walls of the academic building of Pete the Geat St. Petesbug Polytechnic Univesity does not meet cuent egulatoy equiements fo themal potection. In ode to eliminate the evealed discepancy it is necessay to cay out additional wok on the building envelopes enovation by one of the poposed methods of waming: ETICS o VFS. The least expensive method is SFTK, which is chaacteized by lowe estimated payback peiod of investments. Its application can educe the heat losses though the walls by about 57% Implementation of the afoementioned ecommendation will allow to bing close the building into compliance with moden equiements fo themal potection, which will incease the building enegy pefomance class. Refeences 1. V.I. Livchak, AVOK, 3, (2010) 2. V.I. Livchak, AVOK, 6, (2012) 3. N.I. Vatin, D.V. Nemova, P.P. Rymkevich, A.S. Goshkov, Mag. of Civ. Eng, 8, 4-14, (2012) 4. A.S. Goshkov, D.V. Nemova, P.P. Rymkevich, Roof. and Ins. Mat., 2, (2013) 5. A.S. Goshkov, D.V. Nemova, P.P. Rymkevich, Eneg. Sav., 2, (2014) 6. N.I. Vatin, D.V. Nemova, A.S. Goshkov, Build. Mat., Eq., Tech. of XXI cen., 1, (2013) 7. SNiP II-А.7-62* Them. Eng. Des. Reg. 7

8 8. SNiP II-А.6-62 Build. Clim. and Geoph. 9. GOST R Build. and. Cons. 10. SP Them. Pot. of Build. 11. SP Build. Clim. 12. GOST Res. and Pub. Build. 13. GOST R Them. Ins. Com. Fac. Sys. 14. GOST R Cons. Build. Env. Het. 15. D.V. Nemova, N.I. Vatin, A.S. Goshkov, A.V. Kashabin, P.P. Rymkevich, D.N. Tceitin, Cons. of Un. Build. and St., 8, (2014) 16. L. Svatovskaya, A. Sychova, M. Sychov, V. Okepilov, MATEC Web of Confeences, 53, Aticle Numbe (2016) 17. A.S. Goshkov, N.I. Vatin, P.P. Rymkevich, AVOK, 3, (2014) 18. А.А. Romanova, P.P. Rymkevich, A.S. Goshkov, Tech. and Tech. Se. P., 4, (2014) 19. A.S. Goshkov, MSUCE, 12, (2015) 20. A.S. Goshkov, V.I. Livchak, Building envelope: eview and analysis of the egulatoy equiements (Lap Lambet Academing publishing, Saabuecken, 2015) 8