Uneven temperatures are common in multi-room homes. A bedroom over a garage, a room with several exterior walls, or a space at the end of a long duct run may behave differently from the rest of the house.

1. Confirm the Supply Vent Is Open

Furniture, rugs and storage boxes can partly block a register without anyone noticing. Make sure the damper is open and that you can feel airflow when the system runs.

2. Do Not Block the Return-Air Path

Bedrooms often become uncomfortable when a closed door limits the path back to the return grille. A clear return-air path helps the system circulate conditioned air through the whole house.

3. Check the HVAC Filter

A dirty filter can reduce total airflow. If the entire system feels weaker than usual, inspect the filter before focusing only on the cold room.

4. Look for Window and Door Drafts

Cold air leaking around a window, exterior door or attic access can make one room feel much colder even when the HVAC system is delivering normal air.

5. Compare Airflow With Nearby Rooms

If one register has much weaker airflow than similar rooms, a damper, crushed duct, disconnected duct or leakage may be involved.

6. Consider the Room’s Location

Rooms above garages, at corners of the house or with large windows often have greater heating loads. Insulation and air sealing can matter as much as duct airflow.

7. Avoid Closing Other Vents to “Push” More Air

Closing multiple supply vents can change system pressure and does not reliably solve a balancing problem.

Our Practical Take

Write down the room temperature and compare it with a nearby room while the system is running. A consistent pattern is useful information for an HVAC technician or energy auditor.

Related Reading

See our guides on closing vents, drafty windows, and duct leakage.

Source

ENERGY STAR — Heat & Cool Efficiently