Stale bedroom air improved after the door transfer path was restored
Supply air entered the room, but the closed door prevented a reliable return path and CO₂ rose overnight.
✓Measurement Supportedrecorded confirmation level
01 / OBSERVED
→Stuffy bedroom every morning
02 / CONFIRMED CAUSE
→Restricted air transfer with the door closed
03 / REPAIR
→The transfer-air path was corrected and airflow balanced.
04 / VERIFY
Overnight CO₂ peaks fell and morning air quality improved.
WHAT CHANGED THE DIRECTION
The evidence that separated the cause
Supporting clues
- Door-position dependence
- High overnight CO₂
- Supply vent present
Checks performed
- CO₂ log
- Door-open comparison
- Airflow measurement
Field lessonA ventilation system needs both a path in and a path out.
