carbon monoxide alarm

[Zephyr]

Hey folks,

I just finished talking with a co worker who is recovering from a carbon monoxide scare. she had been sick for the past while and found out recently when they checked out her basement and found CO at 700 ppm. She had been sleeping with the door and window closed and it was making her perpetually ill. Here's the scary part, she said she had these 1/2 smoke 1/2 CO alarms in her house. even though the basement was at 700 ppm. (which according to the specs on my kidde alarm should make it sound in 4 minutes) none of her alarms sounded. ( I don't know what brand she had)

This made me question my own alarm. I tested it, and it seems to function correctly. however, I'm not sure where it should be placed. Reading online some say that the detectors should be placed on the ceiling, because the CO is mixed in with the warm furnace air that rises. However, the person who checked out my co workers house said that the CO generally falls, and so the detectors should be lower to the ground.

what do you all think?

This is the alarm I have

Dave

[HeyBub]

I think:

1. I'd like to know the brand and model of the detectors that failed your friend.
2. I'd like to know if she's suing the manufacturer and everybody he ever knew.
3. I'd like to know how you tested yours.

As to your specific question:

There was a long discussion on this very topic sometime back. One group was adamant for an elevated position, another was equally adamant for a lower location.

The discussion died out as one of the groups died out. I forget which.

For the ultimate in peace of mind, get two.

[trader4]

Would also be important to know how old the detector was. I'm not sure what I'd do in this position. With levels that high, one would think the detector would go off in either location. Personally, since I don't spend much time on the ceiling, I have mine about 4 ft of the floor. I have one in the basement, about 15 ft from the furnace/water heater, another one in the master bedroom. I think it's a very good idea to have more than one, as like anything they aren't

100%.

Your friend should consider contacting the Consumer Product Safety Commission, they may be interested in checking it out.

[Oren]

Just four days ago and entire family (mother, father, daughter and six pets were found dead in Las Vegas. The power had been cut off by Nevada Power. The family ran a gas powered generator in the garage (apparently with a door open to allow a power cord in the watch television).

I was racking my head trying to remember what was said about these device failures (sensor element?).

The story is here:

-- Oren

"Well, it doesn't happen all the time, but when it happens, it happens constantly."

[Joseph Meehan]

They don't know what they are talking about. I have been involved in a CO incident, those who were asleep on the floor were fine, those who were sitting up playing cards late, got hit hard.

[Oren]

This may have been it.

"GE Security Carbon Monoxide Alarms. The problem is they fail to detect carbon monoxide after one year of operation due to an internal software error. And there's no "end of life" signal or other indication that there's a problem.

Several security system companies sold these alarms from for about $49. If you have one, contact the installer or service provider to arrange for a replacement. Here's GE Security's phone number:

800-648-7422. "

-- Oren

"Well, it doesn't happen all the time, but when it happens, it happens constantly."

[John Gilmer]

If you took high school chemistry, the answer should be obvious.

CO is somewhat lighter than pure O2 (the ratio of 28/32 but it's not THAT much lighter. CO2 which "settles" is heavier than O2 by the ratio 44/32.

I have always preferred the digital CO detector. Some perfectly normal activities will generate enough CO to put the digital models off zero. (In our case it was cooking on electric stove.) A non-zero reading "for cause" is a confidence builder: you know it's doing something other that flashing every 3 minutes.

As far as placement is concerned, a good candidate is "higher up" in the same room where the CO is most likely originate.

A good location for a second detector is near the bedrooms and, again, high up.

While I can see why folks are upset that the CO detector didn't seem to do its job, the more important question is what went wrong to generate 700 ppm of CO in the first place. CO poisoning cases have happened from time to time as far back as I can remember. Find the cause of the CO and fix it.

Some years ago an IDIOT of a gas company technician "red tagged" my water heater because her detector found 44ppm by sticking the probe in the space between the "funnel" and the actual vent at the top of the gas fired water heater. (IOW: the actual exhaust didn't have enough CO to cause more than minor symptoms.)

It takes a serious problem to put 700 ppm of CO into the room air.

[hallerb]

nstantly."

Your better off buying 2 different manufacturers units one in each sleeping area or level.

At least one should be not just a alarm but a digital readout of level, thats highly useful/

I too was involved in a incident got really sick.

The hot water tanks chimney flue cap cracked, water got in between chimney structure and ceramic liner, it broke fell in clogged chimney.

nothing beats rountine inspection of home on a regular basis looking for troubles BEFORE they occur!

[Doug Miller]

I think you shouldn't take that person's advice. The *fact* is that, at room temperature, the density of CO is only slightly lower than that of air:

Installation of Carbon Monoxide Alarm:

The density of Carbon Monoxide at 20 °C (68 °C) is 0.96716 which is slightly lighter than the density of air (1.00). However, at 0 °C or 32 °F the density is increased to 1.250 which is much heavier than air. Practically speaking, placing the CO Alarm high or low is not a major concern at room temperature. CO permeates a room much like the scent of perfume dispersing uniformly in all directions and in effect engulfs a room. Install your CO Alarm within 40 ft of all rooms used for sleeping purposes.

[LayPerson Tom]

Wow not good! Do you have a link to the article? This is clearly news worthy material.

tom @

[Joseph Meehan]

..

Air: 1.2928 gms/liter CO: 1.2500 gms/liter

Which put it still lighter than air a 0º C. I think you missed the part about CO also becoming more dense at colder temperatures.

My personal experience is that it does not disperse evenly and that there is a significant difference in real life. The unintended experiment that I was part of involved five people playing cards and about 30 sleeping on the floor in a cabin with a fireplace at one end and a furnace at the other. Two of those playing cards went to the hospital, the others had they typical headaches, while no one sleeping on the floor had any noticeable ill effects.

I would seriously disagree with your suggestion to ignore the instructions that come with the detectors and their placement. I will add that the instructions often call for placement at a minimum distance from the wall or ceiling. There is a dead air space in those corners.

[Steve Barker]

Do I DARE ask how you generated CO "cooking" on an electric stove? I put quotes around the cooking word because I can't imagine any serious cooking going on with an electric stove. But, that's another group.

[John Gilmer]

I guess I burned something. Don't know. I had the digital CO detector right in the basement close to the furnace and the water heater for months and the "peak" was always "000".

Had it on the first floor for a week and the "peak" was "010." Not really high enough to be of any concern but makes for a good story!

I think I was able to get a higher reading by burning incense near the detector. The problem, of course, is that the things response quite slowly because they use a complicated organic molecule (the "reacts" like a blood component) to do the actual detection.

[Doug Miller]

And if *you* had taken high school chemistry, you'd be comparing to N2 (79% of the atmosphere) instead of to O2 (20%) -- or looking up the actual density values in the HCP.

[Doug Miller]

Well, it does appear that the source I cited didn't get the density figures correct. You did.

Excuse me? Where the hell did I suggest that?

[Joseph Meehan]

Not directly, but since every such device I have seen has directions to place it high, your statement indicating "Practically speaking, placing the CO Alarm high or low is not a major concern at room temperature." would indirectly conflict with those instructions. It would appear that it was not your intent to do so. It was my intent to clarify that and I fear I was not as careful in my wording as I should have been. Please accept my apology for that.

[Western Alarm]

"Zephyr" inspired greatness with:

RTFM

Mount it at eye level.

[Doug Miller]

Please read more carefully -- that's not *my* statement. That's from the web site that I cited. Any errors there are theirs, not mine.

Thanks.

[John Gilmer]

Yeah. But that would have required that I still remembered the atomic weight of nitrogen. I figued O2 was "gud enuf."

[hallerb]

I had a old computer power supply overheat, and set off the CO detector not long ago. At least that APPEARED to cause the alarm....

Any burning action can cause elevated levels