Ventilation must provide the required supply and extract in individual rooms. One whole-house number cannot show whether a bedroom works with its door closed.
Inputs
Record room uses, occupants, schedules and moisture sources. Check applicable requirements in the current document for the building; no universal per-person rate is assigned here.
Room balance
Define supply, extract and transfer paths separately. Closed doors, acoustic requirements and a cooker hood can affect operation even when total supply and extract agree.
Control modes
Define normal, boost and absence modes. Humidity or CO₂ sensing can support control, but a single hallway sensor cannot represent every bedroom or pollutant.
Installation and balancing
Design flow becomes a verified result after measurement at terminals. Record damper settings, filter condition, unit mode and measurement conditions; check noise at the operating point.
Common mistakes
Do not substitute free-air unit capacity for delivered room flow. Do not reduce supply merely to hide noise: first investigate resistance, velocity and sound transmission.
| Item | Parameter | Check / result |
|---|---|---|
| Design | Room flows | Balance |
| Acceptance | Measured flows | Record |
| Operation | Filters, modes | Recheck |
What this means for your project
Request a room-by-room schedule and balancing record in the brief. Recheck after significant duct or control changes.
Sources and scope of review
Related reading
- Thermal Bridges: Where They Occur and Why They Matter
- House Orientation: What Actually Affects Energy Balance
- How to Choose an MVHR Unit for a House