**Document:** Odour Control and Noise Appendices
**Application:** 09/00837/R — Erection of a flue / vent to rear elevation
**Decision:** Permitted
**Decision Date:** 2009-09-11
**Parish:** Rushen
**Document Type:** report / planning_statement
**Source:** https://planningportal.im/a/63530-rushen-albert-hotel-athol-street-chimney/documents/1382902

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# Odour Control and Noise Appendices

## 5.0 Odour Control Recommendations

UK guidance from DEFRA 'Guidance on the Control of Odour and Noise from Commercial Kitchen Exhaust Systems' is that:

- For new premises or premises covered by planning conditions restricting the impact of odour the system shall be designed to prevent harm to the amenity.
- For existing premises not covered by planning conditions restricting the impact of odour, the system shall be designed to avoid statutory nuisance and shall comply with the principles of Best Practical Means.

### Table 2 - Minimum Requirements For Odour Control

### Objectives

For new premises or premises covered by planning conditions restricting the impact of odour the system shall be designed to prevent harm to the amenity.
To achieve these objectives the odour control system shall include an adequate level of:

1. Odour control; and
2. Stack dispersion.

The overall performance of the odour abatement system will represent a balance of 1 and 2.

### Discharge Stack

The discharge stack shall:

1. Discharge the extracted air not less than 1 m above the roof ridge of any building within 20 m of the building housing the commercial kitchen.
2. If 1 cannot be complied with for planning reasons, then the extracted air shall be discharged not less than 1 m above the roof eaves or dormer window of the building housing the commercial kitchen. Additional odour control measures may be required.
3. If 1 or 2 cannot be complied with for planning reasons, then an exceptionally high level of odour control will be required.

### Odour arrestment plant performance

Low to medium level control may include:

1. Fine filtration or ESP followed by carbon filtration (carbon filters rated with a 0.1 second residence time).
2. Fine filtration or ESP followed by counteractant/neutralising system to achieve the same level of control as 1 .
Maintenance must be carried out to ensure these performance levels are always achieved.

## Appendix 1 Acoustic Terminology

### Decibel (dB)

The ratio of sound pressure which we can hear is a ratio of 1:106 (one: one million). For convenience, therefore, a logarithmic measurement scale is used. The resulting parameter is called the 'sound pressure level' (Lp) and the associated measurement unit is the decibel ( dB ). As the decibel is a logarithmic ratio, the laws of logarithmic addition and subtraction apply.

### $\mathbf{d B ( A )}$

The unit generally used for measuring environmental, traffic or industrial noise is the A-weighted sound pressure level in decibels, denoted $\mathrm{dB}(\mathrm{A})$. An A -weighted network can be built into a sound level measureing instrument such that sound levels in $\mathrm{dB}(\mathrm{A})$ can be read directly from a meter. The weighting is based on the frequency response of the human ear and has been found to correlate well with human subjective reactions to various sounds. It is worth noting that an increase or decrease of approximately $10 \mathrm{~dB}(\mathrm{~A})$ corresponds to a subjective doubling or halving of the loudness of a noise, and a change of $3 \mathrm{~dB}(\mathrm{~A})$ is subjectively barely perceptible.

### Equivalent Continuous Sound Level (Leq)

Another index for assessment for overall noise exposure is the equivalent continuous sound level, Leq. This is a notional steady level which would, over a given period of time, deliver the same sound energy as the actual time-varying sound over the same period. Hence fluctuating levels can be described in terms of a single figure level.

### Frequency

The rate of repetition of a sound wave. The subjective equivalent in music is pitch. The unit of frequency is the Hertz (Hz), which is identical to cycles per second. A thousand hertz is often denoted kHz , e.g. $2 \mathrm{kHz}=2000 \mathrm{~Hz}$. Human hearing ranges approximately from 20 Hz to 20 kHz . For design purposes, the $1 / 3$ octave bands between 16 Hz to 12.5 kHz are generally used. The most commonly used frequency bands are octave bands, in which the mid frequency of each band is twice that of the band below it. For more detailed analysis, each octave band may split into three $1 / 3$ octave bands or in some cases, narrow frequency bands.

### Statistical Noise Levels

For levels of noise that vary widely with time, for example road traffic noise, it is necessary to employ an index which allows for this variation. The L90, the level exceeded for ninty per cent of the time, has been adopted to represent the background noise level.

### Structure Bourne Noise

Structure bourne noise is the transmission of noise energy as vibration of building elements. The energy may then be re-radiated as airborne noise. Structure borne noise is controlled by structural discontinuities, i.e. expansion joints and floating floors.

Some typical noise levels are given below:

[Table omitted in markdown export]

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*Data sourced from the Isle of Man public planning register under the [Isle of Man Open Government Licence](https://www.gov.im/about-this-site/open-government-licence/).*
*Canonical page: https://planningportal.im/a/63530-rushen-albert-hotel-athol-street-chimney/documents/1382902*