Every other room is comfortable but that one room – usually the farthest from the unit, or an addition, or a bonus room over the garage – stays hot no matter what.
You probably came here because…
- One specific room is consistently 5-10 degrees warmer than the rest of the house
- It's usually the farthest from the AC or in a bonus/addition
- Closing off other vents to force air to that room helps a little but not enough
- The room may have vaulted ceilings, west-facing windows, or a lot of glass
What’s actually happening
One hot room usually comes down to duct problems: the run to that room is too long, too small, kinked, or disconnected in the attic. That last one happens more than you'd think.
Bonus rooms over garages are especially bad because the garage floor doesn't hold heat like a conditioned floor and the room is exposed on multiple sides.
Sometimes the real answer is a ductless mini-split for just that room. We do these constantly and they work great, but it's not the first thing to check.
What we do about it
Inspect the duct run to that room
In the attic or crawlspace, follow the flex duct from the main trunk to that room's vent. Is it kinked? Crushed? Disconnected? Full-length? These are all common and cheap to fix.
Check the register and return
Is the supply register fully open? Does the room have a return grille or is it relying on a door undercut? A hot room with no return grille often just needs a return added.
Consider a mini-split for that room
If the duct run is fine and the room still won't cool, a ductless mini-split adds capacity to just that room without touching the rest of the system. We install these for around $3,000-4,500 installed.
When to just call
If you're getting quotes to redo all your ductwork or add a second AC because of one room, get a second opinion first. Sometimes the answer is a $200 duct repair. Call (423) 637-1846 and we'll look at it before you spend big.
Ready to fix it?
Call the family that’s been doing this in the Sequatchie Valley since 1996.