ISO 3382-3 FOR SUSTAINABLE OPEN-PLAN OFFICES

ANC Annual Conference – 29th June 2016

Anthony Chilton

OVERVIEW

Sustainable open-plan office

Case Study

3382-3 Measurements

Post occupancy evaluation

Design approach

SUSTAINABLE OPEN-PLAN OFFICE

Bourne Hill Offices, Salisbury

Conventional Sustainable

Mechanically ventilated Naturally ventilated

Mechanically cooled Passively cooled (concrete soffits)

Low ceilings, high screens High ceilings, low screens

CASE STUDY - KEYNSHAM

CASE STUDY - KEYNSHAM

CASE STUDY - KEYNSHAM

KEYNSHAM – EXTERNAL NOISE

KEYNSHAM – EXTERNAL NOISE

Hard to provide masking noise without disturbance.

50

55

60

65

70

75

80

0 6 12 18 24 30 36 42 48 54 60 66 72 78 84

LAe

q,1

0s

[dB

]

15 minutes of traffic noise (10 second LAeq values)

LAFmax = LAF90 + 17dB

KEYNSHAM – NATURAL VENTILATION

Vent Area approx. 5% of floor area (or 10% of façade area)

KEYNSHAM – ACOUSTIC LOUVRES

0

10

20

30

40

50

60

70

80

63 125 250 500 1000 2000 4000 8000

Sou

nd

Lev

el [

dB

]

Octave Band Frequency [Hz]

Measured unoccupied LAF90

NR30

NR35

NR40

MEASURED INDOOR NOISE LEVEL

LA90 = 40dB

All vents fully open

KEYNSHAM - ABSORPTION

50% of the ceiling area is exposed concrete to provide passive cooling.

The other 50% is perforated aw=0.7 (Class C)

Absorbent outer surfaces to balustrades. Slatted timber.

Absorbent desk dividers.

REVERBERATION CONTROL

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

63 125 250 500 1000 2000 4000 8000

T20

[s]

Octave Band Frequency [Hz]

Reverberation Time, T20(average of 18 interrupted source measurements)

250Hz – 2kHz average = 0.75s

KEYNSHAM - SCREENING

Minimal screening – only desk dividers.

1100mm high (from floor).

Do not block direct sound.

KEYNSHAM – SUMMARY

Low masking noise.

Low absorption.

Low screening.

What is the significance for privacy?

3382-3 MEASUREMENTS

rD (Distraction Distance)

LwA=68.4dB

SPEECH INTELLIGIBILITY

STI

Distance [m]

SPEECH INTELLIGIBILITY

DISTRACTION DISTANCE

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 2 4 6 8 10 12

STIP

A

Distance From Source [m]

rD=5.9m

CLASSIFICATION

Is Class B suitable for Keynsham?

Finnish Institute of Occupational Health

(Keränen, Hongisto, Virjonen)

Class rD

A <5m

B 5 - 8m

C 8 - 11m

D 11 - 15m

E > 15m

POST-OCCUPANCY EVALUATON

Total Performance of Low Carbon Buildings

8 office buildings in the UK, 16 in China.

4 POE acoustic questions.

Acoustic control parameters will be recorded.

CONTROL PARAMETERS

Occupancy

Activity Type (similar to NF 31-199)

Noise Levels

Ventilation Conditions

POE QUESTIONS

If you are dissatisfied with noise levels from colleagues in

your office, please indicate on the plan provided the area in

which the activity of colleagues can cause you disturbance

(see example below).

My Position

Area causingdisturbance

DESIGN APPROACH

http://www.ttl.fi/en/work_environment/physical_factors/acoustictool/Sivut/default.aspx

Screen Height 0% 20% 40% 60% 80% 100%

900mm

LAF90 = 34dB 1300mm

1700mm

Screen Height 0% 20% 40% 60% 80% 100%

900mm

LAF90 = 37dB 1300mm

1700mm

Screen Height 0% 20% 40% 60% 80% 100%

900mm

LAF90 = 40dB 1300mm

1700mm

Screen Height 0% 20% 40% 60% 80% 100%

900mm

LAF90 = 43dB 1300mm

1700mm

Average aw of Ceiling

Average aw of Ceiling

Average aw of Ceiling

Average aw of Ceiling

CLASSIFICATION MAPS

Acoustic Classification(Finnish Institute of Occupational Health)Keynsham

Preferred

CONCLUSIONS

Noise ingress - LAFmax 55dB

Electronic sound masking? – LAF90=43dB

Average aW of ceiling 0.5

Screen height 1350mm

Screens can be glazed above 1100mm.