BS 4142 is the British Standard used to assess the impact of industrial and commercial noise on nearby sensitive premises. It works by comparing the rating level of a specific noise source (adjusted for acoustic character) against the prevailing background noise level at the nearest receptor. A difference of around +10 dB or more indicates a likely significant adverse impact. Around +5 dB indicates a likely adverse impact. At or below background indicates negligible impact. Most local planning authorities require a BS4142 assessment when new commercial or industrial premises are proposed near residential properties, or when fixed plant and equipment is being installed. The 2019 amendment (BS4142:2014+A1:2019) introduced important updates to methodology that all current assessments must reflect.
Air Conditioning Noise Surveys & Assessments
What is an air conditioning noise survey?
With air conditioning units being used more widely than ever, especially in public, commercial and office spaces, it’s crucial to understand how they impact on environmental noise levels and affect noise sensitive receptors in their vicinity – hence the growing demand for reliable air conditioning noise surveys.
In an industrial or manufacturing setting, the noise emitted by an air conditioning unit may be inconsequential. But, in a quieter setting such as residential or office environments – the noise generated by air conditioning units can cause a nuisance. Irrespective of this, if you are installing a new external plant unit (air conditioning units / air source heat pumps) or re-commissioning or re-locating one you will require planning permission.
The only way to be sure about the noise levels emitted by your system is to commission a professional air conditioning noise survey. British Standard BS 4142: 2014 is the official standard for rating and assessing industrial and commercial sound. One of its applications is for assessing sound from fixed installations of mechanical and electrical plant and equipment, including air conditioning units.
Simply put, the assessment method measures the difference between the benchmark ‘background sound level’ and the ‘rating level’ of the industrial source, at the receiver location. The greater the difference between these two reference points, the bigger the impact on the immediate environment. The guidance for BS4142:2014 advises that a difference of circa 5dB+ could indicate adverse impact, while 10dB+ could indicate significant adverse impact. Again, context is key.
How are air conditioning noise surveys used?
Most regularly we are commissioned to undertake an air conditioning noise survey in support of a planning application or to assess a nuisance from an existing air conditioning unit. The scope of this could include applications for any type of scheme, from large industrial facilities to small commercial or office premises. The primary purpose of an air conditioning noise impact assessment to BS 4142:2014 is to satisfy the local planning authority that proposals will not have an adverse impact on the surrounding noise sensitive receptors.
Our thorough air conditioning noise survey includes:
- Background sound level assessment
- Assessment of noise emissions from the A/C unit (or acoustic modelling if the unit is not yet operational)
- Analysis of noise impact to BS4142:2014
- Recommendations for any noise mitigation measures
- Technical report for submission in support of a planning application
Although every case is unique, you can be confident we have an in-depth understanding of the factors that may be impacted by the outcome of an air conditioning noise survey – specifically the intended hours of operation, acoustic specifications of the chosen unit and proximity to the nearest neighbouring property (either residential or commercial).
Should the proposed installation seem likely to cause adverse impact, we will provide you with tailored advice, cost-effective and realistic solutions that will enable you to meet BS 4142:2014 standards, including changing or modifying the proposed unit, re-orientation or realignment, or the implementation of acoustic noise-reducing barriers or enclosures.
Why choose NOVA Acoustics?
NOVA Acoustics is one of the UK’s leading independent consultancies. We offer a dedicated, professional service to a wide range of private and commercial clients through a network of accredited engineers. We have extensive experience of conducting BS 4142:2014 air conditioning noise surveys and can usually offer a fast turnaround on urgent projects. Our expert advice is highly valued.
- Leading independent consultancy
- Professional consulting team
- Practical and cost-effective advice
- Local accredited engineers
- CSCS safety approved
Related article: Extraction System Noise Surveys & Assessments
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