Why are some rooms colder than others?
Uneven temperatures are usually a distribution problem: too little airflow reaching the room, or too much heat leaving it through an under-insulated surface.
Last reviewed 2026-07-15
Rooms above garages, over unheated crawlspaces, at the end of long duct runs, or with large glazed areas are consistently the hardest to condition.
Before adjusting dampers, verify that airflow actually arrives at the register and that the return path is not blocked by closed doors or furniture.
What to check first
- Airflow at the supply register with the system running
- Return path — undercut doors or transfer grilles
- Duct runs in unconditioned space for leaks or disconnections
- Insulation depth above the affected ceiling and around the affected walls
- Window and door weatherstripping in the room
When to call a professional
- A duct is disconnected or damaged in an inaccessible location
- Balancing requires damper work or airflow measurement you cannot perform