April 2025 | Campbell Associates

Invisible threats: understanding PM2.5 and PM10 in your indoor air

Air Quality & Dust

What is an airborne partiuclate?

An airborne particulate, also known as particulate matter (PM), is a microscopic solid or liquid particle that remains suspended in the air. These particles are incredibly diverse in size, shape, and chemical composition, originating from both natural sources like dust and pollen, and human activities such as combustion and industrial processes. Categorized by their aerodynamic diameter, particularly as PM10 (coarse particles) and PM2.5 (fine particles), these tiny airborne components can persist in the atmosphere for varying durations depending on their size, and their presence is a key factor in air quality assessments due to their potential impacts on human health and the environment.

What is the legislation for England?

The HSE have set exposure standards to comply with the requirements of The Control of Substances Hazardous to Health (COSHH) Regulations. These are described in the HSE document EH40, which is updated annually. Currently, these are:

  • 10,000 ug/m3 (8 hour time weighted average) for total inhalable dust.
  • 4,000 ug/m3 (8 hour time weighted average) for respirable dust.

Total inhalable dust is defined as the fraction of airborne dust which enters the nose and mouth during breathing and is therefore available for deposition in the respiratory tract. Respirable dust approximates to the proportion which penetrates to the alveoli within the lung.

European emissions standards have highlighted a yearly average of 40 μg/m³ and 25 μg/m³ for PM10 and PM2.5 respectively. The ‘WHO’ standards outline a guideline of 20 μg/m³ and 10 μg/m³ for PM10 and PM2.5 respectively.

Can they be monitored?

Yes! Absolutely. Our monitors provide reliable, high-quality data on particulate concentrations, enabling local authorities, construction sites, and environmental consultants to effectively assess air quality, identify pollution sources, and demonstrate compliance with the stringent standards set to protect public health across the United Kingdom.

CadnaB Overview

Noise

Datakustik Cadna

Calculation Standards

The following standards are implemented in CadnaB:

  • ISO 12354: Calculation of airborne and impact sound insulation between rooms as well as the airborne sound insulation against outdoor sound via the façade walls.
  • When using ISO 12354, following parameters can be calculated:
    • Performance parameters according to ISO 717-1 (airborne sound insulation) and ISO 717-2 (impact sound insulation)
    • ASTM-parameters (STC, OITC, IIC)
  • DIN 4109: Calculation of airborne and impact sound insulation between rooms as well as the airborne sound insulation against outdoor sound via the façade walls.

Handling and Modelling

CadnaB´s concept is based on the modelling of the whole building. Walls, doors, windows and other elements can be modelled in 2D while seeing the changes in 3D in realtime:

  • Numerous junction types are automatically detected by CadnaB depending on the geometry of the walls and the selected constructions.
  • In addition to the geometry of the walls and the assigned constructions, doors and  windows can be inserted with a few clicks. The construction of these elements is also selected via the construction browser.
  • Furthermore, airborne sound transmitting systems can be added.
  • Complete buildings can be imported, created from scratch or constructed by copying storeys.

Import of Bitmap floor plans

CadnaB supports the import of bitmap files, e.g. containing the floor map. Bitmaps can be comfortably calibrated within CadnaB. Afterwards, entire storeys with multiple rooms or even entire buildings can be easily modelled by drawing the elements on top.

Project Organization

The CadnaB workflow is organised in different modes. Each mode is suited for a certain group of tasks:

  • Project mode: used for entering new objects or modifying exiting objects. In this mode, any type of element can be filtered and displayed.
  • Constructions mode: This mode is used to assign constructions to walls, doors, windows or floors. When an object is opened, the construction browser appears showing all libraries.
  • Results mode: This mode allows to start the calculation, check the results and export a report.
  • Usage mode: In this mode you can assign different types of usage to the rooms within your project.
  • Noise levels: For defining sound levels for rooms or façade walls.

Import of BASTIAN worksheets

CadnaB provides an easy to use import of BASTIAN worksheets. The single room pair can be directly used for calculation (e.g. according to ISO 12354). If the user activates the compatibility mode to ISO 12354, series 2000, comparable results to BASTIAN can be generated.

Import of INSUL files

CadnaB also imports constructions generated by INSUL (Marshall Day Acoustics)*, as XML files. All data including the sketch are imported. For constructions with several parts, such as a slab with a screed, the user can select which one to import. 

*Option PRO required
*Requires exported XML files from INSUL version 9.0.24 or later

Interoperability with CadnaA

CadnaB-buildings can be placed in a CadnaA model with a few clicks to calculate the level in front of the façade. In case of ISO 12354, the interior level can be calculated based on the façade level with consideration of the building acoustic properties. When using DIN 4109, the “relevant exterior noise level” can be calculated and transferred to CadnaB.

Interoperability with CadnaR

  • Manage and organize CadnaR files for an entire building in CadnaB.
  • Use CadnaR in the sending and receiving room to consider the position of sources, receivers and obstacles inside the room. The transmission through the wall is calculated based on the building acoustic properties defined in CadnaB including selected constructions, doors or windows.
  • Automatic calculation of the spatially averaged reverberation time for all rooms which are linked to a CadnaR project.

The “Results” mode

The results mode allows you to check all calculated results, which are organized for every two adjacent rooms. This makes the fast-checking of any specific room pair within a building very intuitive.

  • Airborne and impact sound transmission results (single and 1/3 octave bands)
  • Partial results for separating element and flanks (single and 1/3 octave bands)
  • Information about junctions
  • Interior level results

The result types shown depend on the selected standard, the evaluation parameters and the transmission situation.

Auralization*

In CadnaB, the result of the calculation can be made audible with the help of binaural auralization. This allows the user to imagine the effect of a construc­tional measure. For this purpose, a source in the form of an audio file is sim­ulated in the sending room or in front of the facade, which is then reduced by the calculated sound reduction index.

*Option PRO required

Fulfillment of requirements

In addition to the numerical results, CadnaB allows the inclusion of requirements according to national or local standards. Many predefined requirements are available within the requirements browser. You can then check whether any room pair fulfills the requirement or not by means of comprehensive visual icons.

Export of results

CadnaB can export:

  • Full project reports to MS Word format (.docx).
  • List of constructions into MS Word (.docx)
  • Calculation protocol to MS Excel (.xlsx)
  • Object tables to text format (.csv)

Overview of CadnaA Industry

Noise

CadnaA Industry is especially designed for acousticians specialized in industrial installations. Applications range from the calculation of industrial sites, wind farms or mining plants to HVACs, PAGA systems or even open air events. In addition to the extensive functions for modelling, assessment and presentation of CadnaA, the product CadnaA Industry includes the following industry-specific features:

  • All calculation standards for noise type Industry included.
  • Input of sources as point, line or area with many options to define emission such as corrections, directivity, operating time and many more.
  • Easy import of emission data as .txt or .xlsx file, for example as sound power level (Lw) or indoor sound level (Li). The data is stored in a database and can be shared across multiple projects or users.
  • Extensive possibilities for project organization with the Object Tree. This enables the assessment of complex scenarios to determine relevant sources or source groups.
  • Definition of a 2D, 3D or rotationally symmetrical directivity, which is especially relevant for the calculation of loudspeakers used for PAGA systems or open air events.
  • Calculation of 1/3 octave band width (if supported by calculation standard).
  • Calculation of maximum levels for each receiver.
  • Convenient functions such as a calculator to add or subtract A/B/C/D weighting to an existing spectrum or to convert a 1/1 octave band spectrum to 1/3 (and vice versa).

Overview of CadnaR for industry acoustics

Noise

CadnaR provides powerful tools to efficiently manage any scenario, guiding you through the setup of your acoustic model and the assignment of appropriate absorption, scattering, and transmission properties. 

Whether optimizing an open-space office for a productive work environment or ensuring excellent speech intelligibility in a lecture hall, CadnaR enables you to assess acoustic quality using industry standards and advanced evaluation methods.

Key features of CadnaR include:

  • Cutting-edge calculation methods: particle model, image source model, hybrid model and more. Fast calculation times thanks to innovative technologies such the support of NVIDIA’s CUDA API.
  • Import and input of obstacle objects including barriers, box-type obstacles and polymeshes to allow any kind of complex room shape. Easy definition of the acoustic properties such as absorption, transmission and scattering.
  • Easy import of room geometries via DWG, DXF, SketchUp, IFC and from CadnaR.scan App.
  • Import your speakers in CadnaR, find their optimal position and alignment, calculate reverberation time, signal level, background noise levels and speech transmission index STI to ensure that these messages are intelligible in large public rooms.
  • Automatic calibration of absorption and scattering coefficients to achieve user-defined or measured target reverberation times.
  • Acoustic assessment of open-plan offices based on speech levels and reverberation time according to DIN 18041, ISO 3382-3 and VDI 2569 as well as innovative intelligibility-based approaches such as the STI-Matrix.
  • Extensive possibilities for project organization with the Object Tree and the use of variants. This allows to handle and compare different planning scenarios and therefore allows to find a tailored acoustic concept to improve the situation in your specific project.
  • Calculation of psychoacoustic parameters such reverberation time (T10, T20, T30), Speech Transmission Index (STI) and many more. Cutting edge auralisation techniques, including the effect of several sources at each receiver position.