A site bounded by three roads and the main Waterloo railway which has been developed for both residential and commercial use has achieved a quiet environment thanks to Passivent.

Wimbledon Offices Ltd own the site in Wimbledon and commissioned William Ryder & Partners Architects to design the mixed use development which comprises 37 apartments, a doctor’s surgery and offices in four blocks. All the dwellings include Passivent AV (assisted ventilation) with acoustically treated ducting and Passivent Fresh 80dB acoustic wall inlets.

Noise levels on certain parts of the site were rated category D but only exceeded category C by 1dB. Inclusion of the Passivent AV and Fresh acoustic inlets enabled the dwelling ventilation to be provided without detriment to the sound insulation levels required by the planning consent. Test results show that the daytime targets of 40dB to living rooms and bedrooms and the night time target of 33dB in bedrooms have, in all cases, been bettered.

The Passivent AV system installed consists of boostable humidity sensitive extracts located in the bathrooms and en-suites, which control ventilation automatically on demand with an additional manually operated boost over-ride function. The system, utilising a single low power extract fan, provides automatic ventilation on demand thereby saving excess heat loss and energy, whilst still giving the occupants a level of control. The use of strategically-located acoustic Fresh wall inlets provides sound attenuated replacement fresh air into the apartments.

The Passivent AV whole house system is BBA certified to meet Building Regulations with inlets as small as 4000mm2/ habitable room, compared to Approved Document F1 requirements for 8000mm2: double the size, and a greater penetration through the exterior to allow noise in. The system eliminates the need for separate acoustic boxes, and ensures constant background trickle ventilation without draughts. It also minimises energy consumption and maintenance, as only the low wattage fan requires electricity, and there are few moving parts.