Hot upstairs or one room that never cools? Your AC may not be the problem.
A single hot room is usually a clue, and the fix is usually cheaper than a new AC. Tell us what you are seeing and we point at the likely cause.
Takes about a minute. No spam.
- We rank likely causes by confidence
- Cheap, targeted fixes first
- No contractor pitch, diagnosis first
The usual suspects for a hot room.
Most hot-room problems are one or two of these. Rarely the AC itself.
Attic heat soaking the upstairs
Attics in hot climates reach 120 to 140 degrees. If insulation is thin or air sealing is missing, that heat leaks into the rooms below all afternoon.
Duct leakage in the attic
A typical home loses 20 to 30 percent of conditioned air through leaky ducts running through the hottest part of the house. The upstairs gets the worst of it.
Solar gain on west-facing windows
Direct afternoon sun through a single window can dump 1,500 to 2,500 BTU per hour of heat into one room. Bedrooms and offices on the west side suffer most.
Poor return air
If a room has supply vents but no return path (a closed door, no transfer grille), pressure builds, AC airflow drops, and the room cooks.
Insulation gaps
Knee walls, bonus rooms over garages, and cathedral ceilings often have missing or compressed insulation. The hot room is usually one of these.
Window exposure and glazing
Single-pane or clear double-pane windows in a hot exposure can be the dominant heat source even when the rest of the home is well built.
Humidity
An oversized AC short-cycles, leaving the air clammy. The room feels worse at 75 degrees and 65 percent humidity than at 78 degrees and 45 percent.
Tell us about the room.
Start with a quick request. We come back with a ranked list of likely causes and the cheapest things to try first.
Takes about a minute. No spam.