Problem
Upstairs too hot, or some rooms never comfortable?
When one room or a whole floor stays hotter or colder than the rest, the equipment is often fine — the problem is getting air to that space. Undersized or leaking ducts, too few returns, closed or blocked vents, heat gain from the roof or windows, and a single system serving two floors are the usual causes. Measuring airflow is how the real cause is found.
A comfort problem rather than an emergency. Book an airflow assessment.
What usually causes this
These are the common possibilities, not a diagnosis. A page cannot tell which one it is — that takes a technician testing the system.
- Duct design or damage
- Ducts that are undersized, too long, crushed or disconnected deliver too little air to the rooms at the end of the run.
- Duct leakage
- Leaks in an attic or crawlspace lose cooled air before it reaches the room.
- Too few returns
- Rooms with doors closed and no return path can't get fresh supply air in.
- Two floors, one system
- Heat rises. A single system with one thermostat downstairs often leaves the upstairs hot in summer.
- Heat gain
- Rooms under a hot roof, over a garage, or with large west-facing windows need more cooling than the rest of the house.
- System capacity or airflow
- A system that's low on capacity — dirty coil, weak blower, low charge — shows up first in the hardest-to-reach rooms.
What you can safely check yourself
- Make sure every supply vent and return grille is open and unblocked.
- Try leaving interior doors open to see whether the room improves.
- Replace the filter.
- Set the fan to Auto, and note whether the problem is worse at particular times of day.
Leave these alone
- · Closing vents in other rooms to push air to the problem room — it raises static pressure and can make the system work harder or freeze.
- · Crawling through attics to adjust dampers or ducts.
Call rather than book online if:
What we check when we get there
- 1An airflow assessment measures air delivered to each room, static pressure, and duct condition and leakage.
- 2Depending on the findings, fixes range from sealing or re-routing ducts, adding a return or balancing dampers, to zoning or a ductless mini-split for a room the ducts never reached properly.
What it is likely to cost
Duct and airflow work is quoted after the assessment, because the fix depends on what's found. A ductless mini-split for a single room has a published starting price.
- Diagnostic / service call
- $89
- Ductless mini-split
- From $3,600 / zone
Prices are starting points for standard work in the Savannah area. Final price depends on the system and site, and is confirmed before work begins. Permits and code-required upgrades may be additional.
Questions people ask about this
- Why is my upstairs so much hotter than downstairs?
- Heat rises, the upstairs sits under a hot roof, and many homes use one system with one thermostat downstairs. Duct design and return air upstairs make a big difference.
- Will a bigger AC fix one hot room?
- Rarely. If air isn't reaching the room, a bigger system just cools the rest of the house more — and can make humidity worse.
- Is a mini-split a good fix for one room?
- Often, for an addition, bonus room or converted garage that the existing ducts never served well.
Where to go next
The service that fixes this
Indoor Air Quality
Humidity control, filtration, purification and ventilation — the half of comfort a thermostat does not measure.
Air QualityWork out the decision
Get it looked at
We cover Savannah, the Coastal Empire and the South Carolina Lowcountry. Tell us what the system is doing — you do not need to know the cause. The diagnostic price is given to you before the visit, and the repair price before any work starts.