2y ago

My CO2 / Smoke Detector Scared a Year off my life today, and I have questions. Long.

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.

17 comments

I've had a smoke detector that would routinely trigger when the clothes dryer was operating. I think they detect steam as well as smoke.
- I had an old one that would go off every time anyone would take a shower. Just another vote for steam setting it off.
  
  Certain types of smoke detectors dont detect 'smoke' or 'steam' exactly, but they monitor a small section of air in the unit and if there is enough particulate matter in the air the sensor is triggered and it goes off.
  Because of this they are sensitive to aresols too, such as spray on deoderant.
- I work with fire alarm systems, as others have said, smoke, steam, dust, and even insects inside the detection chamber will trigger a photoelectric smoke det.
  
  Good to know it's also a plague of locusts detector.
So it's the smoke detector, not the CO detector? These are separate devices. A smoke detector will typically be on the ceiling and a CO detector will typically be close to the floor.
I've had smoke detectors which are set off by steam, such as from a hot shower. You can replace it with a style of detector which operates differently, not using photoelectricity to be triggered. Keeping batteries fresh is also supposed to help, but I don't know if it really does.
That said, you may want an alarm for humidity because 82% is quite high and may cause damage to the home.
- If you're referring to Carbon Monoxide detectors [I recognize the OP made an error calling them CO2] commonly referred to as "smoke/CO", then, in the US at least, smoke and Carbon Monoxide detectors are usually combined units. I've never found one to be separated like that. A common example is below. Carbon Monoxide is similar, if not lighter than common air density, so putting one on the floor wouldn't make any real difference.
  https://www.firstalert.com/us/en/products/alarms/combo-smoke-carbon-monoxide-alarms/prc710-10-year-battery-combination-smoke-carbon-monoxide-alarm-prc710/
  
  Huh. I'm in the US, and have always had these as separate units because smoke detectors function best on the ceiling and carbon monoxide detectors function best by the floor (allegedly).
Smoke detectors frequently work by having a teensy little radioactive emitter and a teensy radioactivity detector somewhere close to it. It works a bit like a laser trap in a video game or movie, if you break the laser-beam by walking through it, it triggers the alarm because the detector can no longer see the beam.
But it doesn't have to be smoke. Water particles will do it, dust can do it, especially when there's construction work going on putting the dust in the air... it doesn't matter. It just needs to be enough to break the connection between emitter and detector.
Wet steam and the vapor from humidifiers is pretty effective at triggering it because the droplets are bigger than regular humidity.
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%20CO%20detectors%20were%20sold,on%20www.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
I'm far from an expert on humidity or electronics, but if there was any condensation it's possible a circuit got bridged inside the alarm and triggered it.
This sounds wild but you don't live near Seattle, do you? We just had a minor earthquake and the next morning all my smoke detectors went hog wild. Apparently that can happen?
https://www.hunker.com/12000263/humidity-smoke-detectors

17 comments