One room that’s always hotter or colder than the rest of the house is usually a sign that something isn’t working evenly.
Sometimes the problem is simple. Other times, it’s an airflow or duct problem that’s been there for years. In Los Angeles, we see this a lot in older homes that have been remodeled, expanded, or had HVAC systems changed over time.
What causes uneven temperatures in a house?
Uneven temperatures are often caused by airflow or ductwork problems, but windows, sun exposure, insulation, room design, and HVAC sizing can also play a role.
A room may not be getting enough conditioned air because the duct serving it is too small, damaged, disconnected, or poorly routed. Or the room itself may gain more heat because of large windows, afternoon sun, poor insulation, or high ceilings.
That’s why the first step is figuring out why the room is uncomfortable instead of assuming it just needs more air.
Can my ductwork make one room hotter than another?
Yes. Ductwork is one of the most common reasons one room is hotter or colder than the rest of the house.
An undersized, crushed, leaking, or disconnected duct can reduce airflow to that room. We also see homes that have been remodeled or expanded without changing the duct system to match the new layout.
Simply adding a larger duct or another vent isn’t always the answer. Changing airflow in one part of the system can affect the rest of the house too.
Can closing vents help balance the temperature?
Usually, no. Closing vents in comfortable rooms rarely pushes enough extra air to the room that needs it.
It can also increase pressure in the duct system without fixing the underlying problem.
Before calling, make sure the vents in the problem room are fully open, aren’t blocked by furniture or rugs, and that the filter is clean.
Does an uneven house mean I need a new HVAC system?
Not necessarily. If the rest of the house is comfortable, replacing the equipment may not solve a problem that’s actually in the ductwork, airflow, insulation, or the room itself.
If the system is improperly sized or the house has changed significantly since it was installed, however, the equipment can be part of the problem.
How do you fix uneven temperatures between rooms?
The fix depends on the cause. It might involve repairing or rebalancing ductwork, improving return air, or correcting another airflow problem.
For an addition, converted garage, or another space that’s difficult to serve from the central system, a ductless mini-split may make more sense.
A room that’s always uncomfortable doesn’t necessarily need more air. It needs someone to figure out why it’s different from the rest of the house.