Preventing MVHR Noise in the Apartment Vent
By Wendy Thomas, Residential Product Manager, May 2018
I’m designing London apartments and have encountered problems with noisy needed to provide storage and living space, so the location of the MVHR systems isn’t always ideal. Is there a feasible solution to ensure quiet operation within the constraints of space and layout?
Wendy Thomas, Residential Product Manager - It must be very frustrating to find the MVHR systems that you’ve previously used without any issues are proving noisy on your apartment job. Designing a quiet-running MVHR system for an urban apartment has to take several factors into consideration. Space, overheating and building fabric may all part of the problem.
Consider space in your apartment design. In order to maximise living area and storage space, often the space allocated to the MVHR system dictates the size of the unit, rather than the amount of air it needs to move.
The lightweight wall construction of many affordable and social housing apartment schemes may also be a contributing factor.
An MVHR system should ideally be fixed onto a brick or concrete wall. Partition walls simply don’t have the mass to absorb even the smallest amount of vibration and noise, and can transfer low-frequency noise to the adjacent living and sleeping areas.
Add to this the problem of overheating. London apartments are increasingly being built in noisy sites and on challenging plots, exposing them to traffic noise and air pollution. So opening a window often isn’t possible. This leads to overheating problems which are mitigated by running the MVHR systems at higher speeds. The increased airflow demands placed on MVHR systems leads to higher system resistances and running speeds.
These factors leave designers at risk of exceeding the stringent noise requirements specified in Part F of the building regulations and further defined by CIBSE.
The obvious solution would be choosing a larger MVHR system capable of running at higher speeds at much quieter levels. However, the space constraints often don’t allow this. Nuaire realised that a specialist solution was needed and recently launched its Q-Aire 1Z which is an optional acoustic enclosure for our range of MVHR products. The 1Z is the only complete MVHR acoustic and first fix solution to overcome both noise and ease the installation of heat recovery units.
By integrating the MVHR unit and flexible connections within an enclosure and supporting the internals on anti-vibration mounts, noise and vibration are isolated. As well as considering acoustic solutions like the Q-Aire 1Z, there are other options aside from wall-mounted MVHRs, such as ceiling-void units like Nuaire’s LP1 solution which is designed for apartments with ceiling void restrictions.
This space-saving MVHR system will free-up valuable storage space and give designers greater flexibility due to its very low-depth - just 200mm. I would also advise working with your ventilation designer early on in the design stage to help you avoid the common pitfalls that result in MVHR system vibration and noise. Doing so could save you time, money and extra work!