Uneven Cooling in House
Quick Answer
Uneven cooling is typically caused by blocked vents, ductwork issues, or rooms having different heat loads (sun exposure, poor insulation). Start by checking that all vents are open and unobstructed. Rooms far from the air handler often run warmer.
Safe Checks You Can Do
- 1Open all supply vents - Make sure vents aren't closed, blocked by furniture, or covered by rugs or curtains.
- 2Replace the air filter - A dirty filter reduces airflow to all rooms, but distant rooms suffer most.
- 3Check accessible ductwork - In attics or basements, look for disconnected, crushed, or poorly insulated ducts.
- 4Balance the vents - Partially close vents in cold rooms to push more air to warm rooms.
Likely Causes
- Blocked or closed vents
Furniture, rugs, or intentionally closed vents restrict airflow to specific rooms.
- Ductwork problems
Leaky, disconnected, or poorly designed ducts fail to deliver air where needed.
- Inadequate insulation
Rooms with poor insulation or lots of windows gain heat faster than others.
- Undersized AC system
A system that's too small for your home struggles to cool distant or high-heat-gain rooms.
- Multiple stories
Heat rises, so upper floors are naturally warmer. Single-zone systems struggle with multi-story homes.
When to Call a Pro
- Temperature differences exceed 5-8 degrees between rooms
- You suspect ductwork damage or leaks
- Basic balancing doesn't improve the situation
- Second floor is always much hotter than the first
- You want to add zoning or a ductless mini-split
Related Symptoms