Rebecca Hogg, BSRIA's Acoustic Consultant presents the testing of HVAC products and why it is important. She gives an idea of the noise sources, why frequency should be measured and how to prevent and react.

1. Acoustic Testing of HVAC Products What is being measured and why is it important?
Rebecca Hogg
Acoustic Consultant
BSRIA Test

2. 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. 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. 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. 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. 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. 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. 8
Excellence in Market Intelligence
Chiller – Efficiency vs. Output
0
10
20
30
40
50
60
70
80
Sound Power Level (dB, re 1pW)
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. 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. 10
Excellence in Market Intelligence
Why Measure Frequency?
75dB
A
B
Appropriate use of noise control
Appropriate product specification

11. 11
Excellence in Market Intelligence
0
10
20
30
40
50
60
70
80
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
Sound pressure level, dB re 20 μPa
Frequency, Hz
Why Measure Frequency?
11
Dominant tone at 600 Hz

12. 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. 13
Excellence in Market Intelligence
0
10
20
30
40
50
60
70
80
Sound Power Level, dB re 1pW
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. 14
Excellence in Market Intelligence
Thank You
Contact BSRIA Test:
Rebecca.Hogg@bsria.co.uk
test@bsria.co.uk
+44(0)1344 465600