I need to stop noise from entering an ensuite bed/bathroom via the extractor fan. I intend to build a plywood enclosure with door and need to insulate the interior of the enclosure. What would be the most effective sound absorbing material and where can you obtain it ? Anyone got any ideas ?
I'm not 100 per cent clear of the purpose of the door or its position.
Is it to close the extractor fan duct off when the fan is not in use and stop air borne noise from entering the room from the exterior?
If so then the air tightness of the box joints, where it is mounted on the surface of the wall, and the door is probably more important than adding addition mass or treatment inside the box. Use magnetic or compression seals on the door for air tightness.
Let us know if this was useful and how you got on.