How to soundproof ventilation installations

How to soundproof ventilation installations

By Ruth MacEachern

Product Manager

Having read of the many advantages of mechanical ventilation, such as improved air quality, reduced heating costs, and environmental benefits, you, as a home builder, have decided that this is an ideal way to set your homes apart from the competition and offer added value to your buyers.

However, you have also read about the problems caused by noisy extractor fans and vibrations from ducts and ventilation units and are keen to avoid the expense and hassle of having to deal with customer complaints. In this article we will examine once more the benefits of soundproofing your ventilation system, while also looking at some of the materials and techniques that can be used to soundproof vents and ducts.

Benefits of soundproofing your ventilation system

It is worth mentioning once more, that many problems encountered with  MVHR systems can be “designed out” during the early planning stages in addition to a passive method being adopted, ensuring that the property itself has appropriate insulation and materials to assist with a comfortable home It is essential that you take your time and seek advice during the design, installation, and commissioning of your system. This includes:

• Ensuring that your selected system is appropriate for the build – whether a system is too small or too large, either can result in inefficiency and excess noise.
• A correct installation, e.g. avoiding the use of excessive lengths of ducting, crushed ducts, or improperly sealed ducts that cause leaks or the build-up of pressure (either of which will require your ventilation unit to have to work harder, in turn generating excess noise).
• Thorough commissioning, to set appropriate levels, check that appropriate valves are installed in each room, and to fine-tune air flow rates to ensure the efficient and quiet running of your system.

You will observe that many of the potential pitfalls occur when a system is running inefficiently. For more information on the importance of an efficient ventilation system, you can check out our article on the subject, here. Many of the measures that can be used to soundproof a ventilation system provide secondary benefits in terms of increasing efficiency, for example in providing thermal insulation at the same time as sound insulation.

However, the overriding benefit is that your customer will enjoy all of the environmental, health-related, and financial benefits of a mechanical ventilation system, without the drawback of unpleasant noise detracting from the user experience. This is particularly important for light sleepers. Silencers placed on external vents will also prevent sound from passing from the inside of the property to the outside, meaning homeowners will enjoy increased privacy. We will now look at some of the available products that can be installed to help reduce unwanted noise emissions from your ventilation installation.

Available soundproofing techniques and materials

1. Mineral wool insulation: often combined with a layer of foil (foil-faced mineral wool wrap), this common insulating material is available in various thicknesses and provides both thermal and noise insulation. It is a requirement for ducts running through cold void areas, such as lofts.

2. Rubber foam insulation: rubber coverings characterised by a low thermal conductivity coefficient  and a closed-cell structure. Rubber mats are flexible, and some feature a self-adhesive layer, meaning installation is incredibly simple.

3. Pre-insulated ducting with rubber foam insulation: avoid the need to fit the insulation yourself altogether, by replacing noisy sections of ducting with pre-insulated fittings.

4. EPP thermal ducting – pre-fabricated ducts and fittings are available and made of expanded polypropylene. This material offers a rigid solution that is lightweight, thermally efficient, and easy to install on account of push-fit connections.

5. Internal duct liners: as the name suggests, these are fitted inside the ducts themselves. Similar to mineral wool insulation fitted to the outside of the ducts, these feature a foil coating to prevent wool fibres from coming loose and entering the air stream. This smooth surface also facilitates air flow.

6. Soundproof coatings are available, which can be painted on and transform noise energy and vibrations into low-grade heat – providing further benefits in terms of the heating of your home.

7. Flexible ducting:  Flexible ducting can be made from thermally insulating aluminium, in some cases complete with an insulating layer, or they can be wrapped in an additional insulating material, thus simultaneously improving the thermal efficiency of your ventilation system. Flexible ducting should only be used for final connections on a system and is to be kept to a minimum due to high airflow resistances.  It is important to ensure that the ducting chosen is sufficiently insulated, be that via sleeving or part of the product as standard.

8. Acoustic air vents: advanced acoustic air vents are available featuring an acoustic lining/noise reducer, as well as internal and/or external baffles to help reduce sound from your ventilation system at the point at which it enters a room. EnviroVent also carries a range of ultra-quiet extractor fans, which can help reduce noise from extractor systems in bathrooms and kitchens.

A few additional tips to pass on to home buyers

In addition to the solutions listed above, there are a number of further tips that can help soundproof an acoustic ventilation system. Impress upon those purchasing your homes the importance of maintaining their mechanical ventilation systems, to ensure they are clean and in good repair. Soundproof panelling can be cut to size and used to dampen any excessive noise generated by a mechanical system or provide some much-needed quieter time for those who are prone to noise sensitivity. There are also other options such as baffles that can prevent crosstalk between areas.

Take the issue seriously to avoid future headaches

With environmental and budgetary constraints at the forefront of buyers’ minds, and the futureproofing of homes a key point of focus in the government’s efforts to achieve net zero carbon emissions (read more on changes to regulations here), an MVHR system is a worthwhile investment, adding significant value to your project.

However, all of these benefits can quickly be forgotten if the system creates a nuisance on account of noise emissions. Careful commissioning and a little investment in the soundproofing solutions identified above can avoid the stress and expense of dealing with unhappy customers months or years down the line. If you require help or advice on any of the issues discussed, feel free to get in touch with the experts at EnviroVent.