UK legislation on ventilation acoustics

UK legislation on ventilation acoustics

By Ruth MacEachern

Product Manager

For house builders, the installation of a mechanical ventilation system will allow you to   future-proof the design of your build; offering occupants an improved living environment, reduced heating costs, and knowing you are  contributing to lowering carbon emissions and doing your part to prevent climate change.

However, the level of technical complexity of mechanical ventilation systems has increased significantly in recent years and as such, there are a host of considerations to be taken into account when designing, dimensioning, and commissioning an MEV or MVHR system. Some of these considerations and the support available to house builders are discussed in our article on ventilating the homes of the future. In this article, however, we will focus on just one of these: noise.

Read on to discover what legislation is in place in the UK regarding noise emissions from mechanical ventilation systems, the consequences of failure to comply with prescribed guidelines, and some tips to help you ensure compliance with the relevant laws and requirements in the UK.

The good news: guidelines rather than hard and fast rules

When the UK Building Regulations were first introduced in 2010, Approved Document F contained no stipulations whatsoever regarding noise emissions from mechanical ventilation systems. In actual fact, the document contained a specific and frank statement to the contrary: “The noise caused by ventilation systems is not controlled under Building Regulations”. This has since been replaced with the following statement, in paragraphs 1.5 – 1.7:

“Mechanical ventilation systems, including both continuous and intermittent mechanical ventilation should be designed and installed to minimise noise. This includes all of the following:
• sizing and jointing ducts correctly
• ensuring that equipment is appropriately and securely fixed
• selecting appropriate equipment, including following paragraph 1.6.
1.6         For mechanical ventilation systems, fan units should be appropriately sized so that fans operating in normal background ventilation mode are not unduly noisy.  This might require fans to be sized so that they do not operate near the maximum capacity of the fan when operating in normal background ventilation mode.
1.7         Account should be taken of outside noise when considering the suitability of opening windows for purge ventilation.”

The document goes on to offer guidelines regarding maximum sound levels, recommending a level of 30 dB for noise-sensitive rooms such as living rooms and bedrooms, and 45 dB for other rooms such as kitchens and bathrooms.

Compliance requirements

While Approved Document F stipulates neither specific noise levels nor any requirement for the testing of noise emissions from mechanical ventilation systems, the government has issued a “Domestic Ventilation Commissioning Sheet” in Appendix C of Volume 1: Dwellings, a copy of which can be accessed here. This document, which must be signed and submitted by the person responsible for commissioning within 5 days of commissioning, and requires confirmation by the installer that:

• The equipment manufacturer’s requirements have been followed
• Paragraphs 1.2 – 1.83 of Approved Document F have been adhered to, with details provided as to any deviations*
• There were no abnormal sounds or vibrations upon initial start-up

* Paragraphs 1.2 – 1.83 cover the noise attenuation guidelines outlined above, while also addressing ventilation rates required to ensure appropriate air quality. As the noise levels emitted by mechanical ventilation systems are determined, to a large extent, by air flow rates and pressures within the ducts (in addition to their design and installation), it is clear that careful planning and fine tuning are required to ensure that the commissioning sheet can be completed and submitted in good conscience – although it should be noted the ultimate goal of compliance is, of course, a safe and effective installation to be enjoyed by the end user, and not just a box-ticking activity!

Tips to ensure a successful and compliant installation

- Select a ventilation system that is correctly dimensioned to suit the size of your building, with an appropriate number of vents

- Keep vibration to a minimum by installing the central unit on a solid base, and by using flexible, airtight ducting where possible

- Choose appropriate fan units – EnviroVent carries a wide range of products , including the “Silent” ranges of kitchen and bathroom extractor fans, as well as the MEV 160/300 continuous mechanical extract unit and the energiSava 300/400 MVHR units. that have minimal noise levels

- Make use of professional installers and consult acoustic specialists, who can perform appropriate measurements, and provide advice on noise attenuation measures and relevant noise reduction products.

For more information on the technical specifications for mechanical ventilation installations, consult our article, here, and our recommendations for a professional ventilation design, here.

Finally, don’t be afraid to ask for help

As a house builder, developer or specialist in the acoustic field. It is important that you can focus on your core area of competence – the compliance of your ventilation system need not become a distraction nor a source of stress. With nationwide coverage offering experienced and reliable experts in your area, EnviroVent can suggest suitable products for your individual project, and provide guidance and advice regarding compliance with applicable regulations and acoustic guidelines.