Smoke and CO detectors

[Nofossil]

My good friend Joe hijacked another thread with some excellent comments on CO detectors. I'd like to create a topic-specific thread here and explore it a bit more.

Where should you install smoke and CO detectors to maximize effectiveness and minimize false alarms?

I have a CO detector on our main living level, but none in the basement where the boilers are. I have smoke detectors on every level, but none in the boiler room itself. Should I be doing anything differently?

 

[EForest]

according to Massachusetts building code a CO detector is required in all boiler rooms and in or just outside of all bedrooms.

 

[rreihart]

I've been checking out CO detectors and low level CO monitors, so this is of interest to me. I searched some but did not find the previous discussion. Can you point me in the direction of the hi-jacked thread.

Thanks.

 

[Nofossil]

I've been checking out CO detectors and low level CO monitors, so this is of interest to me. I searched some but did not find the previous discussion. Can you point me in the direction of the hi-jacked thread.

Thanks.

I should point out it wasn't a blatant hijack - just some good observations buried in another thread. Here's the link:
https://www.hearth.com/talk/threads/12118/

 

[canyon]

Does anybody have experience with models/ brands of CO detectors? I almost bought the kidde nighthawk?? battery model and then I read somewhere that it doesn't give a reading until a decent threshold is reached. I might still get one for an alarm but I am looking for a cost effective way to monitor CO levels (with a display). Thanks in advance and I hope this isn't hijacking as I'm new to this.

 

[Nofossil]

Does anybody have experience with models/ brands of CO detectors? I almost bought the kidde nighthawk?? battery model and then I read somewhere that it doesn't give a reading until a decent threshold is reached. I might still get one for an alarm but I am looking for a cost effective way to monitor CO levels (with a display). Thanks in advance and I hope this isn't hijacking as I'm new to this.

Any reply that's reasonably in line with the original topic is fine, and we're pretty flexible. I'm at least as guilty as anyone else at taking a tangent that interests me but contributes nothing to the original topic.

In this case, I'm hoping that we can get some good insights about the best solutions to monitoring our systems for safety.

I have the Kidde, and I'm treating it as 'alarm only'.

Do I remember right that CO is heavier than air and will tend to settle in low places, or is that only CO2?

 

[BrownianHeatingTech]

CO mixes with air. CO2 and LP sink. Smoke rises. Proper level for a detector obviously depends on what you're trying to detect (which is why smoke and combustible gas combination detectors are a silly waste if someone uses LP instead of NG).

Getting a detector with a display is pretty useful. It helps you know exactly how quickly you need to respond to an alarm (CO isn't like a smoke alarm - you have some time to get on your coat and get out reasonably, in most cases). Most detectors also store a "peak" value that can be reset. This can let you know if problems (below alarm level) are occurring while you are away.

You obviously don't want a smoke detector right near the boiler, but a CO detector is a good idea. If you use a gas-fired appliance, a combustible gas detector (in the appropriate location - see above) is a good idea, too.

And yes, Mass is indeed getting somewhat draconian with their rules. The boiler manufacturers are ending up with a whole page (or more) in the manual just dedicated to Mass-only rules. I have some good friends in Mass, and none of them seem stupid enough to need special hand-holding that no one in the rest of the country needs. Maybe they are just exceptions?

Joe

 

[Tony H]

Illinois calls for one CO/Smoke within 15 feet of any sleeping area, this law went into effect 010107.
An additional note I had a CO detector in my house go off a few years ago and called out the FD they detected no CO and when I told my pal who is a fire fighter he got the brand on the first try saying he had been out on dozens of calls for invalid alarms and it was almost always a brand starting with a K . His advice to me was to use a Firex or similar commercial brand rather than the K brand that's so popular. In my house I have 7 or 8 wired to the AC power with battery backup and the great feature is if one goes off they all go off. Great except at 2AM when they all go off because one has a dead battery oh well.

 

[kevin fitzsimmons]

Good timing on the posts as i was just looking at adding more detector's. this link has some insight into placement of the co detectors. The short version is co is roughly the same density as air, but it is usually emitted from heating appliances and is therfore warmer and will likely rise. I have mine in the hall way at the top of my basement stairs. The stove in in the basement and hopefully and co leak would move up the stair will with the hot air. I would like an additional detectors outside our three bedrooms in the common hall. The one detector i have is a combo smoke/co, that has never detected co, but how do i really know it is working? I do fell tired al the time, though i think this is more likely due to the fact that the sun doesn't rise until 8:30, has set by 4:00 and we have two kids under two in the house

(broken link removed to http://www.carbonmonoxidekills.com/placement.htm)

 

[rreihart]

I've read some negative comments about the typical inexpensive detectors not working very well. So I've been looking for something better. I'd also like to see an actual numerical reading. Do the common units do this or do they just alarm at a certain level? Some have recommended the NSI 3000 and the C O experts model 1070. Anyone have thoughts on these or other top quality units?

 

[Gibbonboy]

Mine are Nighthawks, like this one: (broken link removed to http://www.idealtruevalue.com/servlet/the-15927/Detail) . Shows the level, from 0 up, but only alarms on a time/dose weighted calculation. Used to go off when I first lit the stoker, but not at a IDLH level. I borrowed a meter from work to calibrate them, they are very accurate. I have one in the basement where the natural drafts would carry CO past the detector, one in the first floor hallway, and one in the upstairs hall outside all the bedrooms. I also have 6 smoke/heat/fire detectors of varying types. Yes, I'm paranoid, but I've also seen first-hand how detectors can save lives, and how their absence can contribute to the needless loss of life.

Didn't NFPA change this year sometime to mandate a CO detector in houses where there is a combustion-type heat source?

 

[Gooserider]

There is a certain anatomical feature that is fitting to describe my state's officials - just put an "M" in front of it...

They passed a law two years ago requiring all sorts of features in a CO/smoke detector, such that there was NO compliant product available! They finally just came out with one the end of this Summer, it is a BRK / First Alert, Catalog number SC7010BV. It has a photoelectric smoke detector and a CO detector in a hard wired / battery backup / interconnected unit. I have three - one in the basement right at the foot of the stairs to the second floor, one on the first floor between our two bedroom / offices and the main bathroom, and a third on the second floor balcony over the living room, just outside the master BR. These were the locations used when the house was built ~30 years ago for a hardwired Firex smoke setup, which I replaced with these units. It wouldn't meet the "New Construction" requirements for MA, but it was OK on a "Grandfather" basis.

The alarms are cool though, they have different tones for smoke and CO, and a voice alert that tells you what the detected problem was, and the triggered alarm announces it's location (programmed from a list) and latches an LED indicator - the other alarms just tell you the problem and to leave... If you do a test, the CO test part tells you the highest level detected since the last reset.

Only problem I've found is the photo-smoke detector is overly sensitive to steam. If the GF forgets to close the bathroom door tightly and turn on the fan, she will set the main floor alarm off however it has a fairly good silence button to tell it to shut up...

As to CO detection and displays... I also have a non-interconnected CO alarm a few feet from the stove, which I purchased explicitly to have an alarm with an LED display on it - This led to finding that for reasons I don't quite understand, UL PROHIBITS automatic displays of the CO level at less than alarm triggering concentrations - I have to punch a test button on the detector to get a peak reading of what was detected since the last reset. This is annoying IMHO, but I can live with it.

FWIW, however, I did see a hand held CO meter listed in one of my recent Harbor Freight catalogs - don't know if I'd totally trust it given that it's an HF item, but...

Gooserider

 

[Nofossil]

Great info - thanks! I now have something to ask Santa for...

 

[BrownianHeatingTech]

As to CO detection and displays... I also have a non-interconnected CO alarm a few feet from the stove, which I purchased explicitly to have an alarm with an LED display on it - This led to finding that for reasons I don't quite understand, UL PROHIBITS automatic displays of the CO level at less than alarm triggering concentrations - I have to punch a test button on the detector to get a peak reading of what was detected since the last reset. This is annoying IMHO, but I can live with it.

They don't want them being used as test instruments. At least, that's the claim...

Joe

 

[webbie]

As to CO detection and displays... I also have a non-interconnected CO alarm a few feet from the stove, which I purchased explicitly to have an alarm with an LED display on it - This led to finding that for reasons I don't quite understand, UL PROHIBITS automatic displays of the CO level at less than alarm triggering concentrations - I have to punch a test button on the detector to get a peak reading of what was detected since the last reset. This is annoying IMHO, but I can live with it.

They don't want them being used as test instruments. At least, that's the claim...

Joe

Pretty silly claim. I guess next thing you know, our thermometer will lose their scales and our house thermostats will say Cold, Cool, Warm and Hot on them!

 

[BrownianHeatingTech]

Pretty silly claim. I guess next thing you know, our thermometer will lose their scales and our house thermostats will say Cold, Cool, Warm and Hot on them!

Thermometers aren't "life safety devices," so they (UL, etc.) treat them differently.

I use my combustion analyzer for CO "sniffing," but an instrument that expensive is not likely to be purchased by a homeowner for such purposes...

Joe

 

[velvetfoot]

Can a combustion analyzer be used to measure efficiency of a wood burning appliance?

 

[BrownianHeatingTech]

Can a combustion analyzer be used to measure efficiency of a wood burning appliance?

There are analyzers made for wood-fired equipment, but the "standard" oil/gas analyzer cannot. The ones that can handle wood are typically pretty expensive.

Joe

 

[Gooserider]

Just as a FWIW, here is the link to the Carbon Monoxide test meter that I saw listed by Harbor Freight a while back. Looks like a reasonably decent unit, albeit a little on the pricey side - Anybody have an opinion on it?

Gooserider

 

[BrownianHeatingTech]

Just as a FWIW, here is the link to the Carbon Monoxide test meter that I saw listed by Harbor Freight a while back. Looks like a reasonably decent unit, albeit a little on the pricey side - Anybody have an opinion on it?

Heh. Actually, that's very inexpensive, for a CO meter. My combustion analyzer (which is a CO meter, O2 meter, draft meter, and two temp probes, in a fancy case with a computer to calculate results from those measurements) is over 10x that price.

Joe

 

[henfruit]

i just recived 3 new co detectors today, with digital read outs protech brand. they are not commercial so they dont go off at a lower reading. they told me the commercial ones are only good for one year. i also have comming a snifit 50 thay detects o to 1999 ppm .this wii be good for checking differant locations in the house. it seems to me the house ones go off at a higher level than you should be exposed to. i wonder why that is?

 

[Gooserider]

I believe it is UL that sets the standards, and they are apparently on the high side - If you read the fine print in the manuals, they tell you the alarm is based on a time / level basis of how much exposure is considered dangerous to a healthy adult - that if you are in an "extra sensitive" group, you should use different (unspecified) measuring instruments with greater sensitivity. Sensitive groups would include elderly, pregnant, infants and young kids, and others with respiratory or circulatory impairments...

I think they are trying to keep the alarm level as high as possible to minimize alarms caused by false readings or brief spikes in the level, while still offering some protection. One could legitimately ask if this is posing a potential for risk to the more susceptible among us, and / or what the long term risks are for chronic exposure at less than alarm triggering levels...

I don't know the answer

Gooserider