Acoustic and thermal performance evaluation of residence facades Dilara DEMIR TUNCA 1 Istanbul Technical University Istanbul Technical University, Department of Architecture, Istanbul, Turkey Assoc. Prof. Dr. Gülten MANIOGLU 2 Istanbul Technical University Istanbul Technical University, Department of Architecture, Istanbul, Turkey Prof. Dr. Nese YÜGRÜK AKDAG 3 Yildiz Technical University Yildiz Technical University, Department of Architecture, Istanbul, Turkey

ABSTRACT The building envelope plays a critical role in providing acoustic and thermal comfort. However, in different environmental conditions such as different noise levels and climate, the design process be- comes more complex. The aim of this study is to evaluate the performance of building envelope op- tions in terms of acoustic and thermal performance. In this paper, it is desired to make a comparison of scenarios that meet the limit values of acoustic and thermal requirements recommended by the regulations in Turkey. Calculations have been made for a 4m x 4m bedroom with high sensitivity level affected by traffic noise in Istanbul. Simulations have been executed in condition for 30%,50% transparency ratio, with brick, aggregated concrete, and aerated concrete block opaque components, and double glazing, double laminated glazing transparent components. The sound insulation value of proposed facades D nT,A,tr (dB), and the total energy consumptions (heating and cooling) Q (kWh) have been calculated. The scenario set up with aggregated concrete block and double laminated glazing transparent component achieved high performance in terms of acoustic and thermal comfort conditions. This study shows that the importance of acoustic and thermal performance should be considered together for more effective building design in accordance with user needs.

1. INTRODUCTION

Housing is most of the building stock in the world. Rapid urbanization, digitalization, and even the COVID-19 pandemic that is confronted in recent years have caused people to spend much more time in their homes. During that period, human productivity and comfort needs have been affected signif- icantly by indoor environmental quality. Especially, users' acoustic and thermal comfort plays an important role in their needs. Although the concept of energy-efficient housing design has become one of the most important goals for a sustainable future [1], the protection of housing against noise should not be neglected. The effects of noise on human health were described as a threat by the World

1 demirdil@itu.edu.tr

2 manioglugu@itu.edu.tr

3 nakdag@yildiz.edu.tr

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Health Organization and according to “New WHO noise guidelines for Europe” published in 2018 noise is an important public health issue. It has negative impacts on human health and well-being and is a growing concern [2]. These effects can be listed under several headings: hearing impairment against noise, inhibition of speech, effects of noise on sleep, cardiovascular and physiological health, mental health, work performance, general behavior, etc. The negative effects of noise should be min- imized. Unwanted sounds that affect human health should be prevented through the effective building envelope design for new and existing buildings. On another approach, most of the energy gains and losses are due to the building envelope. According to “Eurostat Statistics” in 2019, in the EU, the main use of energy by households is for heating and space cooling their homes (64 % of final energy consumption in the residential sector) [3]. The building envelope's opaque and transparent component area and different material usage directly affect the heat transfer in the envelope. Therefore, the design decisions of the building envelope are directly effective in energy conservation. While studies that deal with thermal, visual, and indoor air quality and energy performance are more common in the literature, studies that deal with thermal and acoustic performance together are less common. Litera- ture research has once again shown the importance of this topic through examples in which thermal and acoustic performance are examined together in recent years [4-5]. The location, building function, orientation, room volume, materials, and the area of the opaque and transparent components of the building envelope directly affect the comfort levels indoor environment. Protecting buildings from noise and decreasing energy consumption have become design criteria which is not only essential but also is a requirement by regulations. Governments and worldwide known institutions have been publishing a variety of regulations, standards, and specific laws about these issues for more energy-efficient and noise-protected buildings. In Turkey, there are main regu- lations and standards are using to provide thermal and sound insulation in buildings. While ‘‘Thermal Insulation Requirements for Buildings’’ [6] represent thermal insulation rules and design principles in terms of building energy performance, ‘‘Regulation on Protection of Buildings Against Noise’’ [7] represent building sound insulation requirements. Regulations have become mandatory for the con- struction of new houses. Also, conditions are specified for changes to be made in existing buildings. It is not enough to meet the requirements of the walls section alone as a construction element, it has become inevitable to evaluate the transparent and opaque components of the facade, the transparency ratio, the volume and dimensions of the room, and the materials together. This study aims to deter- mine the building envelope option with the highest sound insulation performance and the lowest an- nual energy consumption, with the values in accordance with the regulations.

2. METHODOLOGY

As a methodology, a bedroom in a building in Istanbul was simulated by taking the current regula- tions, and the common practices into consideration. Design variables other than the façade and the transparency ratio were kept constant in order to assess the performance of the façades having differ- ent wall-window combinations with different transparency ratios. The energy consumption of these scenarios was calculated and the acoustic performance class in accordance with the regulations was evaluated. Information about the assumptions to be used in the method is explained below.

2.1. Determination of criteria values that affect acoustic and thermal performance In order to determine the required minimum façade sound insulation values, L den (outdoor day-even- ing- night level), noise sensitivity of the receiver room and acoustic performance classification were used. Noise sensitivity of the receiver room, which is a bedroom, is ‘high sensitivity’. In the case

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of high sensitivity rooms, the required minimum façade sound insulation, D nT,A,tr , is L den -x value for each performance class was calculated as seen in Table 1. The regulation specifies the minimum performance requirements; as class C for new buildings, and class D for existing buildings [6].

Table 1: Determination of required D nT,A,tr value for acoustic performance class [6].

Acoustic performance class for high

L den (dBA)

sensitivity level of receiver

55

60

65

70

75

A (≥L den -14) 41 46 51 56 61

B (≥L den -18) 37 42 47 52 57

C (≥L den -22) 33 38 43 48 53

D (≥L den -26) 29 34 39 44 49

Table 2 shows that required overall heat transfer coefficients (U-value) of façade wall, roof, ground floor and the window for Istanbul province under 2 nd climatic region in Turkey [7].

Table 2: Required U-values according to TS-825 standard [7].

City U wall (W/m 2 K)

U roof (W/m 2 K)

U groundfloor

U window (W/m 2 K)

(W/m 2 K)

Istanbul 0,57 0,38 0,57 1,8

2.2. Determination of design variables that affect acoustic and thermal performance • Location It is assumed that the building is located in Istanbul under the temperate-humid climate (2 nd region) conditions and under the different traffic noise. • Building The building determined as a single 3-storey building has include ground, first and second floors. Two sides of the building face the road; two sides are deaf. While each floor of the building has six equal volumes facing a façade, there are 18 rooms of equal volume in the building totally. The building function determined as residential housing (see Figure 1). • Orientation It is assumed that the building oriented south-north orientation (see Figure 1). Evaluations have made just for south orientation. • Room The middle room of the first floor was chosen for calculations in order to include the effect of flanking noise. This allows us to get the value of overall façade sound insulation. Room dimensions deter- mined as a 4m x 4m bedroom. Room height has been considered 3 m. This room has area of 16 m 2 and volume of 48 m 3 (see Figure 1).

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Figure 1: South-north oriented a single 3-storey housing under the traffic noise (perspective-plan)

and the determined room dimensions with area and the volume. • Façade and window transparency ratio Determined dimensions of façade and window related to transparency ratio can be seen in Table 3. There are two options for transparency ratio (TR) as 30% and 50%.

Table 3: Window dimensions according to given facade and transparency ratio.

Façade edge / height (m)

Façade area

Dimensions of window (height/width) for 30% TR (m)

Dimensions of window (height/width) for 50% TR (m)

(m 2 )

4 / 3 12 (1.5/2.4) (2/3) • Thermophysical and sound related properties of building façade components Window options can be seen Table 4. There were used two types of glazing for transparent compo- nents; double laminated glazing-G1, and double annealed glazing-G2. Glazing properties and val- ues are selected from the most used materials in the market. Glazing options were chosen by con- sidering maximum U-value (1.8 W/m 2 K) for window according to TS-825.

Table 4: Thermophysical and sound related properties of the transparent component options.

Glazing of

Layers of materials

Thickness of layers d (mm)

Total thickness d (mm)

U (W/m 2 K)

R w (C;Ctr)

window

(dB)

G1

1-laminated 2-argon (%90) 3-glazing

8.8 8 15

31.8 1.6 42(-1;-3)

G2

1-annealed 2-air 3-glazing

6 9 18

33 1.8 39 (0;-4)

Façade wall options can be seen in Table 5. There were used three types of main wall materials for wall options; brick wall-F1, aggregated concrete (medium dense)-F2, and aerated concrete (G4)-F3. To ensure required U-value, construction layers and thicknesses have been obtained by considering production sizes. Even though some of the options ensured the U-value, they were not examined because they were outside of production sizes. All of the façade wall options used rockwool panel which has 120 kg/m3 density as insulation material, and the same exterior and interior plaster have been used.

Table 5: Thermophysical and sound related properties of the façade wall options.

Façade

Layers/materials λ (W/mK)

Thick

U (W/m 2 K)

TS 825

density

R W(C;Ctr)

wall

ness d (m)

max U

ρ (kg/m 3 )

(dB)

value (W/m 2 K)

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F1 1-exterior plaster (inorganic cement) 2-rockwool panel 3-horizontally per. brick 4-interior plaster (perlite gypsum)

0.38 0.04 0.36 0.29

0.02 0.04 0.19 0.02

0.556 0.57 1000 120 700 800

51(-1;-6)

F2

1-exterior plaster (inorganic cement) 2-rockwool panel 3-aggregated concrete (medium dense) 4-interior plaster (perlite gypsum)

0.38 0.04 0.57 0.29

0.02 0.05 0.14 0.02

0.566 0.57 1000 120 1400 800

58(-1;-4)

F3 1-exterior plaster (inorganic cement) 2-rockwool panel 3-aerated concrete (G4 class) 4-interior plaster (perlite gypsum)

0.38 0.04 0.19 0.29

0.02 0.03 0.135 0.02

0.57 0.57 1000 120 600 800

52(-1;-5)

• Thermophysical and sound related properties of the building components other than façade To evaluate the effect of different façade scenarios on acoustic and thermal performance, the other building components’ properties are determined constant as shown in Table 6 according to the limit values of TS-825 standard. These building components were determined as flat roof, ground floor, interior wall and interior floor/ceiling. All of the components’ U-value ensured lower than maximum value of regulation U-values. Sound related properties of the constant flanking element as interior wall and interior floor/ceiling can be seen in Table 7. Regulation specifies minimum airborne sound insulation value between room for same dwelling is minimum 44 dB for C performance class. Besides that, interior floor/ceiling airborne sound insulation value between room for different dwelling is minimum 52 dB for C perfor- mance class, and the impact sound insulation value is maximum 54 dB. All values ensured that this limit values to evaluation.

Table 6: Thermophysical properties of the constant opaque building components.

Opaque component

Layers/materials λ (W/mK)

Thickness

U (W/m 2 K)

TS 825 max U- value (W/m 2 K)

d (m)

Flat roof

1-gravel 2-glasswool 3-bitumen 4-cement screed 5-reinforced concrete 6-plastering

0.36 0.04 0.5 0.41 2.5 0.4

0.1 0.08 0.04 0.05 0.15 0.02

0.374 0.38

Ground floor

1-cement screed 2-xps insulation 3-reinforced concrete 4-cement screed 5-bitumen 6-cement screed 7-cast concrete 8-earth gravel

0.41 0.03 2.5 0.41 0.5 0.41 1.9 0.52

0.03 0.03 0.5 0.03 0.003 0.05 0.05 0.1

0.54 0.57

Interior wall 1-cement plaster

0.97 0.36 0.97

0.02 0.135 0.02

1.525 -

2-horizontally per. brick 3-cement plaster

Interior floor/ceiling

1-cement screed 2-reinforced concrete 3-plastering

0.41 2.5 0.4

0.05 0.15 0.02

1.994 -

Table 7: Sound related properties of the constant flanking elements.

Opaque component

Layers/materials density

Thick-

D nT,A / L’nTw

Regulation min. airborne

Regulation

ρ (kg/m 3 )

ness d

max. impact sound insulation cri-

(m)

dB

sound insula-

tion criteria D nT,A,tr / D nT,A , dB for perfor- mance class C

teria L’nTw, dB for perfor- mance class C

Interior wall 1-cement plaster

1600 1000 1600

0.02 0.135 0.02

44.3/- 44 -

2-horizontally per. brick 3-cement plaster

Interior floor/ceiling

1-cement screed 2-reinforced concrete 3-plastering

1600 2400 1000

0.05 0.15 0.02

55.5/52 52 54

2.3. Determination of combinations in order to specify scenarios Combinations were determined from F1, F2, F3 façade walls, G1, G2 glazing of windows, and 30%, 50% transparency ratios alternatives. As shown in Table 8, 12 number of scenario were obtained. These scenarios are intended to help evaluate the alternatives.

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Table 8: Scenarios obtained from variables.

Façade

Glazing of

Transpar-

Number of scenario / combination

wall

window

ency ratio

F1 F2 F3

G1 G2

30% 50%

1 / F1-G1-30% 2 / F1-G1-50% 3 / F1-G2-30% 4 / F1-G2-50% 5 / F2-G1-30% 6 / F2-G1-50%

7 / F2-G2-30% 8 / F2-G2-50% 9 / F3-G1-30% 10 / F3-G1-50% 11 / F3-G2-30% 12 / F3-G2-50%

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2.4. Making calculations regarding acoustic and thermal performance In this study energy and acoustic related simulation tools were used separately. The characteristics of the two simulation tools were taken into account for the creation of the model. The geometry of the model was prepared. • Calculations in terms of noise control. In order to achieve the D nT,A,tr value, the R W(C;Ctr) values of the walls and windows must be known. INSUL software was used to obtain R W(C;Ctr) values of the walls. The R W(C;Ctr) values of the windows was taken from the measured value of the manufacturer. INSUL models materials using the simple mass law and coincidence frequency approach and models more complex partitions using work by Sharp, Cremer, and others. s a programme for predicting the sound insulation performance of walls, floors, ceilings and windows. The programme can make reasonable predictions of the transmission loss (TL) and weighted sound reduction index (R w ) for use in noise transfer calculations [8]. To cal- culation of the façade sound insulation D nT,A,tr value were obtained by using software KALKSAND- STEIN-KS which uses mathematical methods described in DIN EN ISO 12354:2017 and DIN 4109- 2 standarts [9]. Sound insulation simulation interfaces can be seen in Figure 2.

Figure 2: Calculation on INSUL and KS interfaces.

• Calculations in terms of energy consumption. In this study, the ‘‘Conduction Finite Differences Calculation’’ method was used through the Ener- gyPlus 9.6.0 [10] computer program. In this method, the performance of the building envelope is calculated through selected points in the surfaces on an hourly base with six time steps. The TARP and DOE-2 algorithms were used to calculate inside and outside surface convection calculations. Annual total energy (heating and cooling) consumption was calculated for the related residential

building volume. SketchUp [11], OpenStudio [12] were used for modelling and IDF Editor with En- ergyPlus interface as shown in Figure 3. The room was assumed to be on the middle of the first floor of a residential building. It was also adjacent to two other rooms in the same floor and the one above, one below, totally four rooms. The building assumed to be in the city context with no obstructing nearby any other buildings. Residential building is used for 24 h. The comfort value for indoor tem- perature during the year was taken as 20 °C in the heating period and 26 °C in the cooling period. Occupancy density of the room assumed 2 people because of the bedroom function. The room was heated by a central heating system boiler fueled by natural gas with hot-water loop radiators. Cooling was assumed by an electrical split air conditioning system. Building was assumed to be balanced mechanically ventilated. The building envelope exposed to sunlight and wind during the day. Weather data was used for the simulations for Istanbul from EnergyPlus data library .epw file [13].

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OP Psi Mets) eee Ree

Figure 3: SketchUp-OpenStudio and EnergyPlus IDF Editor interface. 3. RESULTS AND DISCUSSIONS

The 12 scenario were examined in terms of acoustic and thermal performance in order to determine the appropriate options in different traffic noise levels. Façade sound insulation values, D nT,A,tr , were calculated for each scenario according to façade wall, windows, and transparency ratio variations, are given in Table 9. The highest façade sound insulation value, D nT,A,tr , is 44.4 dB and can be seen at the 5 th scenario. This façade is combined by aggregated concrete-F2, double laminated glazing-G1, and 30% transparency ratio. The lowest façade sound insulation value, D nT,A,tr , is 38.2 dB and can be seen at the 4 th scenario. This façade is combined by horizontally perforated brick-F1, double annealed glazing-G2, and 50% transparency ratio.

Bouse a ST er | = ate

According to results, required performances cannot be satisfied by none of the scenarios in the case of traffic noise L den 75 dBA. Façade sound insulation of 5 th scenario in the case of traffic noise L den 75 dBA cannot be satisfied, however, acoustic performance class A in the case of traffic noise L den 55 dBA, acoustic performance class B in the case of traffic noise L den 60 dBA, acoustic performance class C in the case of traffic noise L den 65 dBA, and acoustic performance class D in the case of traffic noise L den 65 dBA can be satisfied as seen in Table 9. The other scenarios acoustic performances can be read like the 5 th scenario example. The scenarios can be put in order as follows in terms of acoustic performance similarity: 4=8=12 (B and C class) < 3=7=11 (B and C and D class) < 2=10 (A and C and D class) < 1=6 (A and B and D class) < 9 (A and B and C) < 5 (A and B and C and D). Annual total energy consumption (heating and cooling) Q, kWh, were calculated (see in Table 9). The highest Q value, kWh, is 2498.025 kWh and can be seen at the 2 nd scenario. This façade is com- bined by horizontally perforated brick-F1, double laminated glazing-G1, and 50% transparency ratio. The lowest Q value, kWh, is 1755.518 kWh and can be seen at the 7 th scenario. This façade is com- bined by aggregated concrete-F2, double annealed glazing-G2, and %30 transparency ratio. Façade wall thickness also were given in Table 9.

Table 9: Acoustic and thermal performance comparison in terms of scenarios.

Number of

Wall Thick-

Annual total energy

D nT,A,tr

Acoustic performance class for high sensitivity level of re-

scenario / combination

consumption (heat-

(dB)

ness (mm)

ing and cooling) Q

ceiver under the different noise level (L Aeq )

(kWh)

55 60 65 70 75

1 / F1-G1-30% 2 / F1-G1-50% 3 / F1-G2-30% 4 / F1-G2-50% 5 / F2-G1-30% 6 / F2-G1-50% 7 / F2-G2-30% 8 / F2-G2-50% 9 / F3-G1-30% 10 / F3-G1-50% 11 / F3-G2-30% 12 / F3-G2-50%

270 270 270 270 230 230 230 230 205 205 205 205

1799.278 2498.025 1762.300 2426.353 1791.960 2490.644 1755.518 2419.102 1793.851 2491.800 1757.797 2421.190

42 41.1 39.7 38.2 44.4 42.6 40.9 38.9 43 41.8 40.3 38.5

A B D - - A C D - - B C D - - B C - - - A B C D - A B D - - B C D - - B C - - - A B C - - A C D - - B C D - - B C - - -

Combined graphic was obtained in terms of energy consumption value Q, kWh, and façade sound insulation values, D nT,A,tr by matching. Combined graphic represents that result values can be in con- flict in terms of acoustic and thermal insulation as seen in Figure 4. It is not easy to say there is a single solution that optimizes all criteria. However, the 5 th scenario, which is combined by aggregated concrete-F2, double laminated glazing-G1, and 30% transparency ratio, can be read the best scenario when compared the others. It is seen that energy consumption Q, kWh, is higher at a transparency ratio of 50% compared to a transparency ratio of 30%. Façade sound insulation values, D nT,A,tr , is higher at a double laminated glazing type of window compared to a double annealed glazing type of window.

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Figure 4: Combined graphic of acoustic and thermal performance.

While analyzing the findings, alternatives that minimize energy consumption and maximize sound insulation were targeted. When the findings of scenarios 1-2-3-4 created with the horizontally perforated brick-F1 façade wall group are examined, it is seen that: • The increase in the transparency ratio increases the energy consumption and negatively affects the sound insulation performance. As the heat gains increase with the increase in glass perfor- mance, annual energy consumption has increased. Considering the 1st and 3rd and 2nd and 4th scenarios where the transparency ratio is kept constant and the glass types are changed, the sce- nario that is a positive effect in terms of thermal performance has a negative effect in terms of acoustic performance. When the findings of scenarios 5-6-7-8 created with the aggregated concrete-F2 façade wall group are examined, it is seen that: • Because of the sorting type, the findings from the scenarios showed similar behavior for each wall group. However, this group of walls showed better thermal and acoustic performance than the other groups. • The 5th scenario is in this group with the best performance.

‘Combined graphic of acoustic and thermal performance ‘ache of wea elastin “Asma wil eoeey conmmption (ating nd cotng) QIK) * Da A)

When the findings of scenarios 9-10-11-12 created with the aerated concrete-F3 façade wall group are examined, it is seen that: • The scenarios consisting of this wall group performed better than horizontally perforated brick but worse than aggregated concrete in terms of thermal and acoustic performance. While the general findings show that increasing the transparency ratio negatively affects both perfor- mances, the thermophysical and sound-related properties of glass reversely affected the performance. 4. CONCLUSIONS

This study evaluates that the sound insulation value of proposed facades D nT,A,tr (dB), and the total energy consumptions (heating and cooling) Q (kWh) in the context of residence building in Istanbul. To make evaluation some of the design variables were taken constant. To understand the effects of façade, façade wall, window and transparency ratio were showed variety. Calculations have been made by simulations. According to calculation, the best scenario can be find in case of the different traffic noise level, as well. In this process, U-value and R W(C;Ctr) value have affected the results sig- nificantly as input data. These values were taken scope of the regulations in Turkey. On the basis of the study results, the following conclusions can be reached: • Acoustic behavior and energy reduction strategies should be meshed by the effective façade de- sign options for the residential house and for their users’ comfort needs. • It was concluded that glass type had more important effects for sound performance, while trans- parency ratio had more important effects for energy consumption. • The 5 th scenario, which is combined by aggregated concrete-F2, double laminated glazing-G1, and 30% transparency ratio, can be read the best scenario when compared the others. • When choosing the thermophysical and sound-related properties of the glass, care should be taken to make a selection that will not adversely affect energy consumption but will positively affect sound insulation. This result shows the importance of glass technology on acoustic and thermal performance. In the light of the study, the proposed evaluation methodology can be used further studies that they include with changing other variables such as location, climate, orientation and the volume. Also, other studies should be conducted with lots of façade wall, window types, and transparency ratio for assessing the impact of the residence façades on the acoustic and thermal performance. In case of an increase in design options and scenarios, methods such as optimization, and a multi-criteria decision making will also need to be used. Combined graphics can be useful for the analysis and presentation of results. 5. REFERENCES

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Legislation and Initiatives (2020). 2. World Health Organization. Environmental Noise Guidelines for the European Region (2018) 3. Eurostat Energy consumption in households (2019).

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