Vibration

Sound is essentially vibration in air, so the topic is familiar to us. From a noise control perspective, it's critical to understand how it is generated and propagated.

Vibration in structures, the ground and from machinery may effect humans and it's usually with that in mind that it causes concern.

Ground borne vibration from construction, transportation etc may cause cosmetic or structural damage to buildings or causes disturbance to occupants of the buildings. It may also cause re-radiated noise in buildings.

Occupational vibration may cause damage or task impairment to people at work, typically from hand-arm vibration (power tools etc) or whole-body (vehicles, platforms etc) vibration.

Planning

The Department of Housing, Local Government and Heritage (DHLGH) provides planning guidelines and planning exemptions for wind farms and wind turbines - the Wind Energy Development Guidelines (WEDG06). These set a general lower fixed limit at nearby noise sensitive locations of: 45dB(A) or; a maximum increase of 5dB(A) above background noise In low noise environments it recommends a daytime LA90, 10min level between 35-40dB(A). The UK's ETSU-R-97 “The Assessment and Rating of Noise from Wind Farms” and the Institute of Acoustics Good Practice Guides are currently the preferred method of assessing wind farm noise for planning purposes and are used to supplement the guidance contained within the WEDG06. The WEDG-06 guidelines are currently under review and the draft guidelines include proposed new standards aimed at reducing noise nuisance.
Compliance

A planning condition for post-installation noise monitoring is often required. This is usually a long-term programme perhaps up to 12months. The draft WEDG guideline require that planning authorities should impose planning conditions in relation to noise limits and deveopers conduct noise monitoring in accordance with the IoA GPG Supplementary Guidance Note 5: Post Completion Measurements.
Structural Health Monitoring

By performing long-term continuous Structural Health Monitoring (SHM) it is possible to monitor and track a structure’s state and carry out condition-based maintenance to ensure structural integrity. On a wind turbine blade, we can detect damage, locate it, and follow its progression. To find out more, check out these couple of videos on solutions from HBK: Structural Health Monitoring of Wind Turbine blades. Predictive Structural Health Monitoring of Wind Turbine blades.
References

IWEA 2022 annual report. Wind Energy Development Guidelines (WEDG06) Draft Wind Energy Development Guidelines (2019) Institute of Acoustics Good Practice Guides DCCAE: Department of Communication, Climate Change, and Environment's website has information on the future role for wind energy in Ireland and the new Renewable Electricity Support Scheme (RESS). Structural Health Monitoring

Enfonic has a wealth of experience in all manner of acoustic related projects.

Established in 2003 we are a leading independent acoustic consultancy with offices in Dublin and London. Our team of consultants provide specialist advice through all project stages; from planning to detailed design and compliance assessment.

We specialise in projects in the environmental and architectural fields; in particular wind turbine noise, impact assessments for planning, architectural design, complaint investigation.

Experts in noise measurement and analysis, we are pleased to provide assistance on any acoustic related project.