I have a back bedroom with sealed windows, and it gets dry sometimes. It’s for a person with horrible allergies. This room is so clean you could eat off the floor so to speak. I run a humidifier set to 60% with distilled water for the person in there. When I checked on it last night to see if it needed to be filled, the humidity had gone up to 82%. This was because a ceiling fan had been left on and the sensor in the humidifier wasn’t getting correct data from the moving air (I think). My hallway smoke / Co2 detector went off as soon as I opened the bedroom door. It would not clear until I pointed a hair dryer at it, then it shut the hell up.
TLDR: My smoke detector doesn’t like humidity all of a sudden?? and went off and would not clear. It has been more humid than that in the entire house without humidifiers running, and I have the same detectors in other locations with no issues.
I assume you mean “CO” detector. CO2 is Carbon Dioxide and I don’t think you went out and purchased and installed a detector for that.
High humidity levels can absolutely cause a false alarm on a CO detector. Example: https://safeinhomeair.com/carbon-monoxide-humidity/
I’ll also point out that not all CO detectors are created equal. There was a lot of news about this earlier this year where a number of CO detectors sold on Amazon simply did not work, or did not meet published safety and detection standards. Here’s an example of some of the serious warnings that were published: https://www.cpsc.gov/Newsroom/News-Releases/2023/CPSC-Warns-Consumers-to-Immediately-Stop-Using-GLBSUNION-and-CUZMAK-Digital-Display-Carbon-Monoxide-Detectors-Due-to-Failure-to-Alert-Consumers-to-Deadly-Carbon-Monoxide-Sold-on-Amazon-com#:~:text=The CO detectors were sold,on www.SaferProducts.gov . Following that announcement, there were several other brands and models that were flagged as being non-compliant. If you haven’t done so already, find your make/model and verify that it’s not one of the sub-standard units that were pawned on Amazon for years.
CO detectors also need to be replaced (they don’t last forever). Most use chemistry to detect CO levels, and that chemistry begins degrading as soon as the unit is built. Some last just a couple years, some are designed to last up to 10 years, but the point is - they all go bad eventually. How old is your detector?
Smoke detectors can also be fooled by high moisture.
I usually don’t buy smoke/CO combo units (I prefer separate detectors for each thing), but I do have a combo unit in a hallway in my upstairs - and it’s got a great feature where it announces by voice what is triggering the alarm (“smoke” or “carbon monoxide”). Does yours do that or does it just sound the same alarm regardless of what was detected?
My mistake, it’s carbon monoxide and smoke