Readings at 1 metre
Hi Les, the council have been out and done there test they said the tonal noise has gone and the resident is happier. Thanks. David
Quiet Fan Technology (QFt)
fan noise reduction without silencers
Qft reduces tonal noise at source at a fraction of the cost of traditional techniques such as silencers and enclosures. Moreover, it achieves this noise reduction without the increased power consumption associated with conventional silencers, lasts the lifetime of the fan without maintenance and can be retro-fitted with little down-time. Applications include: extract fans, ID fans, chillers, air conditioning plant, process and ventilation fans, HVAC systems... Click for video