Why does a closed room always smell musty?
Closed rooms trap humidity and lack air circulation, causing a persistent damp cardboard smell that returns as soon as windows are closed or candles are blown out. Temporary fixes like scented candles and airing out the room only mask the odor rather than resolving the trapped moisture.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1Leaving the room door openDid this help you?
- 2Switching the thermostat fan from ON to AUTODid this help you?
- 3Cutting an inch off the bottom of the doorDid this help you?
- 4Using a dehumidifierDid this help you?
- 5Leaving the window openDid this help you?
- 6Using scented candlesDid this help you?
- 7Heating up the place and improving ventilationDid this help you?
- 8Reducing humidityDid this help you?
- 9Using DampRid or a dehumidifier in the basementDid this help you?
- 10checking if the walls are bulgingDid this help you?
- 11observing if the smell gets stronger after rainDid this help you?
- 12Turning off the ACDid this help you?
- 13Calling the emergency maintenance lineDid this help you?
- 14Leaving the apartment to stay elsewhereDid this help you?
- 15Notifying neighbors about potential dangerDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“It’s been over a month now, and I’ve tried scented candles and having the window open and the smell is gone while the window is open or the candle is burning but as soon as I close it or blow out the candle it returns.”source ↗
“My house has a mudroom that has a set of stairs that lead to the basement.”source ↗
“We have a dehumidifier and the basement smells fine, but the stairwell radiates a strong damp smell that infiltrates the mudroom.”source ↗
“Any suggestions on who to contact to investigate this or is it just get damp rid and leave it be?”source ↗
“So I live in an apartment and this morning I woke up to a really weird smell.”source ↗
“I can't access my HVAC room, only maintenance can, so I can't see what's going on in there. First thing I did was call it in. Now it's after hours and they're closed on the weekends.”source ↗
“The smell is almost sweet but it also is chemically like burnt plastic. I have asthma and the longer I've been in the apartment the more difficult its becoming to breathe and I seem to be developing a headache.”source ↗
“I also can't get the windows open for some reason to vent the space.”source ↗
Where this came up
People with this problem also raised
- 14How to stop an apartment from smelling like pets
- 4Why does my hall closet smell like cat pee on certain days?
- 19Why does my house smell like cat urine when there is no visible mess?
- 13Why is my AC air handler wet and smelly?
- 11Why do my towels still smell musty right after washing?
- 3Why does my house still smell like chemicals after HVAC cleaning?