CO alarm

Bubbalowe · Post by **Bubbalowe** » Tue. Oct. 23, 2018 8:02 am

McGiever wrote: ↑
Mon. Oct. 22, 2018 12:41 pm
Never test a CO sensor by placing in a strong concentration like a open stove or stove pipe...High concentrations of CO will contaminate the delicate sensor and effect it's accuracy forever after.
Likewise holding sensor at the tailpipe of a automobile will render same.

All CO test and alarm devices have a integral "TEST" Button for proof of work ability.

Roger on test cycle. Placed alarm 4 ' away on shelf, interested in testing stove/ chimney leakage, everything seems good. Curious if small amounts of carbon monoxide are present and how much before setting off alarm.

rberq · Post by **rberq** » Tue. Oct. 23, 2018 9:35 am

Bubbalowe wrote: ↑
Tue. Oct. 23, 2018 8:02 am
Roger on test cycle. Placed alarm 4 ' away on shelf, interested in testing stove/ chimney leakage, everything seems good. Curious if small amounts of carbon monoxide are present and how much before setting off alarm.

I have seen max CO readings of 10 to 15, in summer, from road traffic. Rarely see any in winter.
I believe amounts have to be fairly high, for a period of time, before the alarm sounds. Duration is longer than you might think before it alarms. I have seen a table of CO vs. time to cause the alarm -- can't remember where.

nickdearing88 · Post by **nickdearing88** » Tue. Oct. 23, 2018 12:31 pm

The Knighthawk units I just ordered say they have a threshold before sounding....I think it's 30 PPM.

Post by **Lightning** » Tue. Oct. 23, 2018 12:33 pm

Right, they sound at particular thresholds based on exposure time.

Bubbalowe · Post by **Bubbalowe** » Wed. Oct. 24, 2018 8:58 am

www.carbonmonoxidekills.com/are-you-at-risk/carbo ... de-levels/

Looks like alarms show 0-29 ppm as 0.

lsayre · Post by **lsayre** » Wed. Oct. 24, 2018 9:04 am

Would it be possible for a moderator to change CO2 to CO in the subject line of this thread. Future searches for CO in the subject line will not find this thread.

coalnewbie · Post by **coalnewbie** » Wed. Oct. 24, 2018 10:51 am

So the old alarms go off at 30ppm, that is good but not great. It is not where you are in life it's all about the trend. Right now I expect and get a 0ppm reading round my coal stoves. If that changes to say 5ppm and then 10ppm, I want to know about it in advance as something is not right. The only way to fly is a digital reading going to zero and a limit alarm.

rberq · Post by **rberq** » Wed. Oct. 24, 2018 12:32 pm

www.carbonmonoxidekills.com/are-you-at-risk/carbo ... de-levels/

Thanks! There are some interesting numbers in this link. A cigarette is as dangerous as the coal stove. Note especially the hazard posed by women – and all these years I thought thrown objects were the biggest danger during that special time of the month.

0-2 = CO level in exhaled breath of healthy non-smokers who do not live with gas ovens, but only if not recently CO poisoned, not acutely stressed, and for women, not in the premenstrual phase of their cycle.
10-30 = CO level in exhaled breath of smokers within one to two hours after they last smoked. Exhaled CO in smokers remains chronically above 5ppm until days after they quit smoking.
25 = CO level above which Baltimore fire department requires firefighters to put on self-contained breathing apparatus.
30-70 +/-3 = lowest CO range in consumer CO alarms are required by UL2034 to sound, but only after this level has been continuously sustained for over 30 days. This is meant to (and effectively does) insure that consumer CO alarms never provide any warning at CO levels below 70ppm.

Freespirit · Post by **Freespirit** » Sat. Oct. 27, 2018 11:18 pm

My understanding the clock doesn't start on them until you put the battery in. When you do you are suppose to write the date on it. I was told to put them no higher than 3 feet of the floor co is a gas so it is heavy and starts low then rises from there. If it is high you will be breathing a lot of it before your detector goes off.

Post by **coaledsweat** » Sun. Oct. 28, 2018 7:09 am

lsayre wrote: ↑
Wed. Oct. 24, 2018 9:04 am
Would it be possible for a moderator to change CO2 to CO in the subject line of this thread. Future searches for CO in the subject line will not find this thread.

Done, thank you.

lsayre · Post by **lsayre** » Sun. Oct. 28, 2018 7:27 am

coaledsweat wrote: ↑
Sun. Oct. 28, 2018 7:09 am
Done, thank you.

Many thanks!!!

rberq · Post by **rberq** » Sun. Oct. 28, 2018 9:13 am

Freespirit wrote: ↑
Sat. Oct. 27, 2018 11:18 pm
... put them no higher than 3 feet of the floor co is a gas so it is heavy and starts low then rises from there. If it is high you will be breathing a lot of it before your detector goes off.

CO mixes pretty evenly in the air and the detector can be just about any height.
There's generally lots of heated air rising off the stove, and those convection currents will help in the mixing.
If a CO detector is combined with a smoke detector, it is almost always placed high on the wall or on the ceiling.

freetown fred · Post by **freetown fred** » Sun. Oct. 28, 2018 9:39 am

I've got 3--stove room is receptacle height (plug in/batt. combo) Others are 1' down from ceiling. Like FS said--I've seen 3' suggested regularly.

titleist1 · Post by **titleist1** » Sun. Oct. 28, 2018 9:45 am

CO does mix pretty well with air in the house so I like to mix the heights of the CO monitors. The one in the basement where the stoker runs is ceiling height since the warm air from the stove is at that height and cool return air is at floor level. Upstairs i have one at about the 3' height in the bedroom area since that is about the height where we are breathing while sleeping. The third one in the house is about 18" off the floor plugged directly into the outlet. The additional normal smoke / CO detectors are all at ceiling levels.

coalkirk · Post by **coalkirk** » Sun. Oct. 28, 2018 10:14 am

Freespirit wrote: ↑
Sat. Oct. 27, 2018 11:18 pm
My understanding the clock doesn't start on them until you put the battery in. When you do you are suppose to write the date on it. I was told to put them no higher than 3 feet of the floor co is a gas so it is heavy and starts low then rises from there. If it is high you will be breathing a lot of it before your detector goes off.

Actually CO is slightly lighter than air. It's a myth that it is heavier. For our purposes we should just consider it equally buoyant with air. The fact that it is a byproduct of combustion means it will be in warm air which of course will rise. Bottom line is just be sure you have at least 1 CO alarm per level in your home. Electric with battery backup is best. The sensors in CO alarms are only reliable for 5 years and then they should be replaced. Otherwise you could wake up dead.