AIRAH Presentation Case studies in HVAC system noise issues

SLR Consulting Australia Pty Ltd 21 August 2013

Luke Zoontjens

The client / documentation refers to a ‘soundproof’ or VIP space

Use of the prefix ‘acoustic’

Interior services are exposed / open / perforated ceiling

Residential building, or the site immediately borders residences

The site is next to major infrastructure such as rail or freeways

There are scientists, precision equipment, patients, lab animals

Green Star / ESD requirements

Encountered any of the following?

The client / documentation refers to a ‘soundproof’ or VIP space

Use of the prefix ‘acoustic’

Interior services are exposed / open / perforated ceiling

Residential building, or the site immediately borders residences

The site is next to major infrastructure such as rail or freeways

There are scientists, patients or lab animals

Green Star / ESD requirements

Encountered any of the following?

Environmental Acoustics in WA

How big is the consulting industry here?

29+ private firms in Perth alone at last count In no particular order: AECOM, Aurecon, EcoAcoustics, EDC, GED, GHD, HSA, LGA, NDY, SLR, Vipac, ERM, 360Env, MDA, WGE, Precision, SVT/NVMS, Hewshott, WP, Coffey, AI, QuietAcoustics, NDE, URS, Dinglebird, VDM, Instrulabs, Sealhurst, Instrulabs.

• www.acoustics.asn.au • ~600 members nationally, 60 in WA • ‘Learned’ society • Annual conferences and input into

professional standards • Acoustics Australia technical journal

• The peak professional association in the industry; • Up-to-date technology and state of the art practices, Code of

Ethics; • Members work only within their nominated areas of competence

and maintain professional indemnity insurance cover; • Free of commercial activities which may affect their impartiality; • Commitment to undertake regular professional training and

development of all staff.

www.aaac.org.au

WA Members

(Formerly Heggies)

www.aaac.org.au

DESIGN FRAMEWORKS IN WA

Design Frameworks • State authorities - noise regulations, planning

policies • Local authorities / ‘Sound Attenuation’ policies • Australian standards – comfort, productivity,

fire/life safety, privacy • Industry Guidelines – AIRAH, AAAC etc. • National construction code • Green star / ESD rating tools • Client and user expectations of quality

CASE STUDIES

ADELAIDE

Domestic systems guidance • http://www.fairair.com.au • AIRAH Air Conditioning Residential Best

Practice Guideline (Western Australia) • Installers Guide to Air Conditioner Noise,

RACIRB / Dept Env, Water & Catchment Protection

Section 80 of EPA1986• 80(1) generally states that a person who installs

any equipment which, when operated, emits unreasonable noise commits an offence under the Act.

• The penalty for an offence under Section 80 (1) is $5,000 for an individual or body corporate.

Section 80 of EPA1986• 80(2) generally states that if an occupier is

convicted of committing an offence under the Act because of someone committing offence under 80(1), that occupier may recover the cost of the installation, together with the amount of any penalty imposed on him from the installer by action in court.

Environmental noise limits • Assigned levels for residential buildings under

state noise regulations vary due to ‘influencing factor’, assume LA10 35dB (10pm-7am)

• Note that 5-10dB adjustments are made if the noise has annoyance characteristics (e.g. tonal whine, deterioration over time)

• AIRAH guidelines of LAeq 45dB maximum during the day and LAeq 35dB maximum at night at property boundary – varies between states

1. Distance factor – Assume boundary; within 15m of neighbouring building

2. Barrier factor – 0 if line of sight, 5 or 10 depending on fence – 0 for roof mounted (e.g. evaporative)

3. Reflection factor – 0, 3, 6 depending on surrounding structure – 0 for roof mounted (e.g. evaporative)

Basic approach

57 0 0

Consider roof level installation 10m from boundary

57

45 10 3

Consider ground level installation 2m from 1.8m wall

52

ADELAIDE

AS/NZS 2107 Reception areas target: ~40-45dB(A) Actual: ~61dB(A)

Lessons learnt

• Intake and discharge flow conditions

• Fan unit mounting arrangements

• Lightweight metalwork and panel mode responses

ADELAIDE (again)

Mech Tender

Mech As-Built

AS/NZS 2107 target: ~35-40dB(A)Actual: ~52dB(A)

Lessons learnt

• Beware of areas where the architectural brief calls for perforated metal and feature/exposed ceilings.

• Identify small cellular shared offices and low density workspaces as among the most sensitive.

• Flexible ducting reduces opportunities for future noise control options.

AS/NZS 2107 target: ~30dB(A) State Noise Regulations Assigned

Level: LA10 35dB(A) Actual: LA10 ~44dB(A) Add +5dB for tonality Add +15dB for indoor measurement =64dB(A) … 29dB exceedance

Lessons learnt • Beware of extreme noise control requirements in

residential buildings, particularly those remote from busy roads and commercial areas, and involving mixed uses.

• There is always a physical limit to the performance of noise and vibration treatments; services cannot always be located where it is convenient.

• In a post construction phase of a building, achieving more than a 10-15dB noise reduction via path controls only is excellent.

CLOSING DISCUSSION