EN09 0085 FORET - CSTB€¦ · > Rémy FORET CSTB - Center for Building Science and Technology Effect of spacer designs on acoustic performance of windows. 27/10/09 | EURONOISE 2009

27/10/09 | EURONOISE 2009 | Edinburgh | CSTB-DAE-LABE | PAGE 1

> Rémy FORETCSTB - Center for Building Science and Technology

Effect of spacer designson acoustic performance

of windows

27/10/09 | EURONOISE 2009 | Edinburgh | Sound Insulation in Buildings | CSTB-DAE-LABE PAGE 2

Effect of spacer designs on acousticperformance of windows

1. Introduction

2. Tests description1. Description of an Insulating Glazing Unit (IGU)

2. Tested configurations

3. Experimental configurations

3. Sound reduction results1. Sound transmission through 4-16-4 insulating glazing unit

2. Experimental results

3. Discussions

4. Conclusions



1. Introduction

Laboratory measurementsaccording to ISO 140-3

Important variation of soundreduction index

30 dB ≤ Rw ≤ 35 dB

24 dB ≤ Rw+Ctr ≤ 30 dB

Rw of 92 windows 4(16 - 20)4

0

5

10

15

20

25

30

35

40

45

50

30 31 32 33 34 35Rw

Num

ber

ofm

easu

rem

ents

RA,Tr of 92 Windows 4(16 - 20)4

0

5

10

15

20

25

30

35

40

45

50

24 25 26 27 28 29 30

RA,Tr

Nu

mb

er

ofm

easu

rem

en

ts

Minimum for French certification of windows



1. Introduction

Rw of 92 windows 4(16 - 20)4

0

5

10

15

20

25

30

35

40

45

50

32 33 34 35

Rw

Num

ber

of

mea

sure

ments

All

ALU

PVC

Wood

RA,tr of 92 windows 4(16 - 20)4

0

5

10

15

20

25

30

35

40

45

50

24 25 26 27 28 29 30

RA,tr

Num

ber

of

mea

sure

ments

All

ALU

PVC

Wood

Minimum for French certification of windows

Rw of 92 windows 4(16 - 20)4

0

5

10

15

20

25

30

35

40

45

50

32 33 34 35

Rw

Num

ber

ofm

easure

ments

All

Window

Door Window

RA,tr of 92 windows 4(16 - 20)4

0

5

10

15

20

25

30

35

40

45

50

24 25 26 27 28 29 30

RA,tr

Num

ber

ofm

easure

ments

All

Window

Door Window



1. Introduction

Disparities on sound reduction possibilities:

> Type of casement

> Air tightness

Despite these two obvious parameters, others caninfluence:

> Gas filling the cavity

> IGU panes thickness

> IGU structural connections

> Spacer bar

> Sealants (tightness barrier & sealant barrier)



1. Introduction

To avoid thermal loss by edges,glass industry developed so-calledlow conductive spacers or « warm-edges » (lower conductivity thanaluminium)

g

12%12%

46%46%

18%18%

48%48%

UUww = 2.4= 2.4W/(m.K)W/(m.K)

UUww = 1.6= 1.6W/(m.K)W/(m.K)

Heat loss

PVC

Up to 40% of total thermal losses of a building by the windows



2. Tests description

A. Insulating GlazingUnit (IGU)

> Standard IGUs> 2 panes of glass

> Gas cavity (air or argon)

> Spacer bar (aluminium)

> Sealant (PU)

> New IGUs with « warm-edges »> Spacer bar (having a lower

conductivity than aluminium) ornone

> Sealant barrier (PU, Silicone…)

4 4

3

6.5

Float glass pane

Tightness seal (butyl)

Molecular sieve

Sealant barrier(polyurethane)

Spacer bar (aluminium)

16

Foam withmolecular sieve

Vapour barrier

PS, PU, Silicone

Thermo plastic

PS, PU, Silicone

Foam spacer Thermo plastic spacer

Standard IGU

IGU with « warm-edge » spacers




B. Tested configurations> 7 configurations of 4-16-4 IGU

> Different combinations of spacer barand sealant (including “warm-edges”techniques)

> Blocked parameters with variableones (if possible) to investigate theinfluence of spacer bar type andsealants barrier type

Butyl sealPolyurethaneThermo plasticConfiguration 7

NoneHot melt butylFoamConfiguration 6

Butyl sealPolyurethaneThermo plasticConfiguration 5

Butyl sealPolyurethaneCompositeConfiguration 4

Butyl sealPolysulfureAluminiumConfiguration 3

Butyl sealHot melt butylAluminiumConfiguration 2

Butyl sealPolyurethaneAluminiumConfiguration 1

Tightness sealtype

Sealant barriertype

Spacer bar typeConfiguration #




C. Experimental set-up

> European Laboratory of BuildingAcoustic (LABE)

> Measurement according to the ISO140-3 Standard

> Overall weighted index Rw(C;Ctr)according to ISO 717-1 Standard

> Each previous configuration:

> 1.45 x 1.48 m² aluminiumprojecting window

> 1.23 x 1.48 m² IGU



3. Results

10

15

20

25

30

35

40

45

50

55

60

10

0

12

5

16

0

20

0

25

0

31

5

40

0

50

0

63

0

80

0

10

00

12

50

16

00

20

00

25

00

31

50

40

00

50

00

One-third octave band centre frequency [Hz]

So

un

dre

ductio

nin

de

xR

[dB

]

CONF #1 - Rw+Ctr = 28 dB CONF #2 - Rw+Ctr = 29 dB



CONF #7 - Rw+Ctr = 27 dB

10

15

20

25

30

35

40

45

50

55

60

10

0

12

5

16

0

20

0

25

0

31

5

40

0

50

0

63

0

80

0

10

00

12

50

16

00

20

00

25

00

31

50

40

00

50

00


So

und

reductio

nin

dex

R[d

B]





IGUs in an aluminium casement IGU alone

ef

ss

ss

21

210 60

²)1(12

2

²

Eh

cfc

210 Hz

2950 Hz



3. Results

10

15

20

25

30

35

40

45

50

55

60

10

0

12

5

16

0

20

0

25

0

31

5

40

0

50

0

63

0

80

0

10

00

12

50

16

00

20

00

25

00

31

50

40

00

50

00


So

un

dre

ductio

nin

de

xR

[dB

]





10

15

20

25

30

35

40

45

50

55

60

10

0

12

5

16

0

20

0

25

0

31

5

40

0

50

0

63

0

80

0

10

00

12

50

16

00

20

00

25

00

31

50

40

00

50

00


So

und

reductio

nin

dex

R[d

B]





IGUs in an aluminium casement IGU alone

CONF. #6

Foam spacer bar

Hot Melt

CONF. #2

Aluminium

Butyl

Hot Melt

CONF. #6

Foam spacer bar

Hot Melt

CONF. #2

Aluminium

Butyl

Hot Melt

6 dB



3. Results

Results> Huge disparities (same order than

PVB laminated glass with PVBinterlayer)

> Rw+Ctr from 26 dB to 29 dB for awindows with 4-16-4 IGUs

> Remark: minimum required acousticperformance for French certificationof window ACOTHERM AC1Rw+Ctr≥28 dB

> Depending on the spacer bar andthe sealants type, the window iscertified or not

> The spacer bar and sealant typeshave an influence on the soundreduction index R

2527Butyl sealPolyurethaneThermo plasticConfiguration 7

2526NoneHot melt butylFoamConfiguration 6


2628Butyl sealPolyurethaneCompositeConfiguration 4

2527Butyl sealPolysulfideAluminiumConfiguration 3

2729Butyl sealHot melt butylAluminiumConfiguration 2

2628Butyl sealPolyurethaneAluminiumConfiguration 1

Rw+Ctr

IGU(dB)

Rw+Ctr

Window(dB)

Tightness sealtype

Sealant barriertype

Spacer bar typeConfiguration

#



3. Results

Results

> Influence of the spacer bar ?> Influence of the sealant barrier ?> Influence of the tightness seal ?




2628Butyl sealPolyurethaneCompositeConfiguration 4

2527Butyl sealPolysulfideAluminiumConfiguration 3



Rw+Ctr

IGU(dB)

Rw+Ctr

Window(dB)

Tightness sealtype

Sealant barriertype

Spacer bar typeConfiguration

#



3. Results

Uncertainties/checking ofthe results

> Mounting of the IGUs was checked:

good repeatability

> A 2nd test campaign was led on IGUs(from different manufacturers)mounted in PVC sash

> The same tendencies wereobserved




Rw+Ctr (dB)Tightness seal

typeSealant barrier

typeSpacer bar

typeConfiguration

#

0

10

20

30

40

50

60

70

100

125

160

200

250

315

400

500

630

800

1000

1250

1600

2000

2500

3150

4000

5000

Fréquence [Hz]

Indic

ed'a

ffaib

lissem

en

ta

cou

stiq

ue

R[d

B]

CONF #2 - Rw+Ctr = 29 dB CONF #2bis - Rw+Ctr = 29 dB



3. Results

10

15

20

25

30

35

40

45

50

55

60

10

0

12

5

16

0

20

0

25

0

31

5

40

0

50

0

63

0

80

0

10

00

12

50

16

00

20

00

25

00

31

50

40

00

50

00


Sou

nd

red

uctio

nin

de

xR

[dB

]

Measurement - CONF #6 - Rw+Ctr = 26 dB


Computation - CASC (TMM)

10

15

20

25

30

35

40

45

50

55

60

100

125

160

200

250

315

400

500

630

800

10

00

12

50

16

00

20

00

25

00

31

50

40

00

50

00


So

un

dre

du

ction

ind

ex

R[d

B]



Computation - ARGOS (Modal method)

Using Transfer Matrix Method Using Modal approach

ModellingModelling

ef

ss

ss

21

210 60

²)1(12

2

²

Eh

cfc

210 Hz

2950 Hz



4. Conclusions

Conclusions> The spacer bar and sealants type have a major the sound reduction index R of IGUs and thus windows> These observations can be made on both measurements (IGUs alone or equipping a double leaves

projecting window)> It affects edge damping and peripheral coupling and thus R (Rw+Ctr)> Quid of impact of tightness barrier seal type ?> Attention has to be paid to avoid non-regulatory situations…(DnTA,tr≤30 dB)

Perspectives> Large test campaign on IGUs (2010)> Finite Element Method modelling> Necessity of PhD thesis on the subject (2010)> The performance of an IGU is not only based on glass and gas cavity thicknesses> For glass manufacturers, necessity to take into account both thermics AND acoustics in their

development



Acknowledgement

We gratefully acknowledge:> Chairmen: Bob CRAIK and Carl HOPKINS

> CSTB: Catherine GUIGOU CARTER / Jean-Baptiste CHENE / Philippe JEAN

> French Ministry of Housing (especially DHUPFrench Housing, Urban planning andLandscape Department)

> VEKA company for providing windows

> OUEST Alu company for providing windows

Thank you for your attention

Documents

EN09 0085 FORET - CSTB€¦ · > Rémy FORET CSTB - Center for Building Science and Technology Effect of spacer designs on acoustic performance of windows. 27/10/09 | EURONOISE 2009