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How Can I Avoid MVHR Installation Issues

Dear Wendy,

By Wendy Thomas, Residential Product Manager, June 2014

I’m a building contractor who has recently been awarded a new housing development project to include Mechanical Ventilation with Heat Recovery (MVHR). Recently I’ve heard bad press about poor installations resulting in noisy systems that don’t perform properly. How can I minimise noise and installation issues and make sure that the MVHR systems perform efficiently, without increasing time and costs on site?

Wendy Thomas, Residential Product Manager- Mechanical Ventilation with Heat Recovery (MVHR) systems have been labelled as complex to install, maintain and operate, however the problems rarely lie with the systems themselves. Poor installation of ductwork and units, and incorrect commissioning can result in airflow rates not being achieved, resulting in failure to meet building regulations. This will have a negative effect on the indoor air quality of the property, causing damp and condensation and impacting on the wellbeing of the occupants.

System performance and indoor air quality will both be compromised if the correct steps aren’t followed from the design stage through to commissioning, but support and guidance is available to you at no extra cost. Some manufacturers now offer full design services in-house, so, rather than considering your ventilation when you start on site with the joists, ceilings and other services already installed, involve them right from the start when designing your building. If your manufacturer uses design software they can provide you with a full design that conforms to building regulations, detects clashes with other systems, and works with your site, so avoiding costly on-site remedies when you come to install your units.

Armed with a full ducting design and advice on the correct ducting and ancillaries, you can concentrate on ensuring your installation follows industry best practice and that the system is correctly commissioned by a qualified person. Following industry best practice is the only way to guarantee the best performance of your MVHR system and to avoid costly and timely delays on-site. Some manufacturers now offer free accredited NICEIC installer training for their suppliers, sharing their experience in the correct installation of MVHR systems. In order to guarantee good performance throughout the life of the systems regular maintenance must be carried out in accordance with the manufacturers’ requirements.

By training your installers, you can ensure your building projects are handed over on time and on budget, and that any issues surrounding poor installation, excessive noise and poor indoor air quality are completely eradicated. The leading manufacturers are keen to promote best practice and as well as training, many provide guidance documents and videos offering valuable advice, hints and tips for getting it right and avoiding costly mistakes.

If you have a domestic ventilation question that I can help with I'd love to hear from you. Contact me by email: