Quiet ventilation results from planning the unit, ducts and air transfer. A quiet device alone does not guarantee a quiet bedroom.
Transmission paths
Distinguish fan noise through ducts, casing radiation, structure-borne vibration and room-to-room cross-talk. Each transmission path needs its own treatment.
Operating point
High duct resistance changes the fan operating point. Check duct sizes, bends, terminals and filters; compare published sound data at the required flow and pressure.
Duct planning
Allow space for attenuators and service access. Door undercuts or transfer grilles must satisfy both ventilation and acoustic needs.
Acceptance
Check normal and boost operation with typical door positions. Agree the noise criterion, measurement location and conditions before procurement rather than after occupants complain.
Common mistakes
A flexible connector does not address every sound path, and closing a valve can create new noise. Do not sacrifice required airflow instead of correcting ducts or vibration isolation.
| Item | Parameter | Check / result |
|---|---|---|
| Unit | Casing and vibration | Location |
| Duct | Fan sound | Attenuator |
| Rooms | Cross-talk | Acoustic path |
What this means for your project
Include acoustics in ventilation selection. Require room checks at the agreed airflow rather than relying solely on the unit datasheet.
Sources and scope of review
Related reading
- How to Choose an MVHR Unit for a House
- Ventilation Rates: How Much Air Does a Home Need?
- House Orientation: What Actually Affects Energy Balance