acoustic testing of hvac products - what is tested and why is it important?

Acoustic Testing

of HVAC Products What is being measured

and why is it important?

Rebecca Hogg

Acoustic Consultant

BSRIA Test

2 Excellence in Market Intelligence 2

BSRIA Test

• ISO/IEC 17025 accredited laboratory ( UKAS No.1053).

• Listed on NANDO as a Notified Body (NB 0480).

• Product validation and verification for:

• CE marking

• Thermal performance

• Efficiency

• Smoke emissions

• Acoustics

• Corrosion

• EN and International standards.

• Product development and bespoke testing.

• On-site and witness testing.

3 Excellence in Market Intelligence

Overview

• What are the common noise sources?

• Which test standards/criteria?

• How can acoustic test data be used?

• Why is acoustic testing important?

4 Excellence in Market Intelligence

Noise Sources

Airborne noise

- Noise that is transmitted through the air

Structure-borne noise

- Vibration that is transmitted through structures and re-radiated as noise

5 Excellence in Market Intelligence

Sound Power Level BS EN ISO 3741

• Sound characteristic product testing in accordance with

BS EN14511:2011 Parts 1-4, referencing BS EN 12102:2008

• Requirement of MCS (UK) and EHPA QL

• Testing at rated conditions

6 Excellence in Market Intelligence

Sound Absorption BS EN ISO 354

• Materials can be designed to absorb sound.

• Applicable to wall and ceiling panels, casing materials, duct lining.

• Sound absorption coefficient:

• 0 (fully reflective) to 1 (full absorptive)

7 Excellence in Market Intelligence 7

Energy Labelling

Mandatory from 26 September 2015

Applicable to space heating and hot water products

Heat pump labels to include:

– Appliance details

– Energy class

– Consumption, efficiency, capacity etc.

– Noise

Indoor unit sound power level

(if applicable)

Outdoor unit sound power level

8 Excellence in Market Intelligence

Chiller – Efficiency vs. Output

0

10

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So

un

d P

ow

er

Leve

l (d

B, re

1p

W)

One-third Octave Band Centre Frequency (Hz)

Maximum efficiency

Maximum output

Overall A-weighted sound power level = 61 dB(A)

Overall A-weighted sound power level = 66 dB(A)

9 Excellence in Market Intelligence

Sizing, Installation & Commissioning

9

System with two dominant noise sources:

Fan

Pump

Specification:

2 l/s water flow rate

Products specified to not cause noise nuisance

Solution:

Reduce system pressure drop Refit fan casing Remove air from system Lower pump speed

Problem:

1 l/s water flow rate at highest pump speed

Higher noise levels than product specifications

10 Excellence in Market Intelligence

Why Measure Frequency?

75dB

A

B

Appropriate use of noise control

Appropriate product specification

11 Excellence in Market Intelligence

0

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0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000

So

un

d p

res

su

re le

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l, d

B r

e 2

0 µ

Pa

Frequency, Hz

Why Measure Frequency?

11

Dominant tone at 600 Hz

12 Excellence in Market Intelligence

Prevention & Reaction

• Product development

• Qualifying for a scheme

• Product specification Prevention

• Installation problems

• Commissioning problems

• Reactive noise control Reaction

12

13 Excellence in Market Intelligence

0

10

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80

So

un

d P

ow

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Le

ve

l, d

B r

e 1

pW

One third octave band centre frequency (Hz)

Overall A-weighted sound power level = 40 dB(A)

Overall A-weighted sound power level = 59 dB(A)

What happens when acoustics is considered?

14 Excellence in Market Intelligence

Thank You

Contact BSRIA Test:

Rebecca.Hogg@bsria.co.uk

test@bsria.co.uk

+44(0)1344 465600