my carbon monoxide detector went off today.....

[laser3kw]

Hey all,
awhile ago there was a discussion about using propane torpedo heaters or construction heaters in an enclosed area (shop garage). There was lively debate about it and the risk of carbon monoxide. This isn't about re-opening that whole can of worms.
I have used both propane torpedo heaters and construction heaters in my 30 x 40 for a couple of years. But I did go out and buy a carbon monoxide detector - just for peace of mind. Since then I have about 50 hours of burn time at 80000 btu level without a peep from the detector.
Well today it went off! Not from the heater, but because I finished off a rebuild of a Tecumseh snow blower and was tuning the carb. I did the first fire up and was tweeking the carb and let it run for about 20 minutes to get a good heatup.
I shut it off and proceeded to drain the gas tank and pull off a leaky shutoff valve when I hear the ear piercing warning. The CO detector sets about 6 ft off the ground about 10 ft from where I was working. I thought "that's odd. maybe it malfunction". So I took it outside and aired it out and reset it. All was quiet. Took it back inside and after 5 minutes or so - there it goes again. I opened the over head door and the walk-in door for about 5 minutes but that didn't stop it. So that was it for today, cleaned up and shut it down.
Now I sit here and relive all the times I did that throughout my life - an never new I had entered that zone.

I end this post with the urgency for all to get a carbon monoxide detector - just for peace of mind.

 

[gahrajmahal]

What brand and where did you get it?

 

[laser3kw]

lifesaver dc from Menards

Carbon Monoxide detector link

 

[Milton Shaw]

That's about right for a small engine. The cars built since the mid 90's burn so clean that if you had a 100 mile commute and then cranked your lawnmower up. You just made more pollution just starting the mower than you did in the 100 mile drive. The exhaust coming out of the modern car has less CO than the air that went in the air cleaner.

 

[gungatim]

wow, 20 minutes running a small engine in a shop that size? glad you walked away from this one...I won't run any engine for more than a minute in my 30x40 without the fans on and door open at least a couple feet.

 

[Rookie2]

The only warning you may feel is a headache, then your walking a fine line !

Yes.....1-2 min. tops CO Kills !

 

[Cyberbear]

And, you may wish to mount the unit a little closer to the floor level since CO is heavier than air and has a tendency to settle down to where you are working, or sleeping for home use.

 

[rlitman]

And, you may wish to mount the unit a little closer to the floor level since CO is heavier than air and has a tendency to settle down to where you are working, or sleeping for home use.

No!

Air is mostly N2. 14x2=28
CO has a MW of 12+16=28

CO has the same density as air (or close enough for all practical purposes).
Best practices with a CO detector is to put it at a convenient height. Since I have ones with a digital display, I prefer eye level.

The danger from CO is that it binds to the hemoglobin in your blood better than oxygen, so you die from oxygen deprivation. It also takes a lot of time for the CO in your blood to be released. So it is dangerous both at high concentrations over a short time period, but ALSO at relatively low concentrations if exposed for a longer period, because it can build up in your blood.

https://en.wikipedia.org/wiki/Carbon_monoxide_poisoning

As the concentration increases, the amount of time you can survive exposure decreases.
But there is a big catch here. Engines and unvented heaters produce more CO as they run richer. In the case of combustion inside starting with fresh air, the engine/heater consumes oxygen, and produces CO2 (as well as some CO as a product of partial combustion, among other things). As the O2 concentration in the air goes down, and the CO2 levels go up, the exhaust will produce increasing amounts of CO. So, while it may not start out too bad, things can quickly go from bad to the worst.

 

[redmondjp]

A good warning - don't run any engine in an enclosed space. I have CO detectors in my house and the one in the laundry room closest to the garage will register a non-zero reading if I leave a car running in the driveway with the garage door open.

 

[Harrison2]

once ran up a minibike in my dads garage. mixture was so off that after just a few minutes the exhaust was cherry red. felt dizzy and sick for a few days. really should have shut it off and opened the door rather than adjusting it for a hour.

 

[Bighead38]

I almost lost my life to carbon monoxide poisoning. Actually wasn't just me but my entire family except pops as he had left for work. Something in the old heating system failed. My dad left for work and my mom was complaining of a headache. She gets regular headaches so it was dismissed and she went back to sleep. A little while later my neighbor called the cops because my mom wasn't at the bus stop with is kids. Cops came and broke into the house. We were all unconscious and carted out. The doctors said another couple minutes and we would have all been done.

Point is carbon monoxide is no joke. Spend the couple dollars for the cheap insurance. Glad your ok OP.

 

[rice rocket]

Wow, holy ****...



...your neighbors are nosy!

 

[nehog]

... let it run for about 20 minutes to get a good heatup.
I shut it off ...

Mine will go off if a car is running inside for more than a minute or so, putting a car on the lift with the door closed will do it most times. I suspect that a snow blower (inefficient engine) might be almost as bad.

 

[Jlbc212]

No!

Air is mostly N2. 14x2=28
CO has a MW of 12+16=28

CO has the same density as air (or close enough for all practical purposes).
Best practices with a CO detector is to put it at a convenient height. Since I have ones with a digital display, I prefer eye level.

The danger from CO is that it binds to the hemoglobin in your blood better than oxygen, so you die from oxygen deprivation. It also takes a lot of time for the CO in your blood to be released. So it is dangerous both at high concentrations over a short time period, but ALSO at relatively low concentrations if exposed for a longer period, because it can build up in your blood.

https://en.wikipedia.org/wiki/Carbon_monoxide_poisoning

As the concentration increases, the amount of time you can survive exposure decreases.
But there is a big catch here. Engines and unvented heaters produce more CO as they run richer. In the case of combustion inside starting with fresh air, the engine/heater consumes oxygen, and produces CO2 (as well as some CO as a product of partial combustion, among other things). As the O2 concentration in the air goes down, and the CO2 levels go up, the exhaust will produce increasing amounts of CO. So, while it may not start out too bad, things can quickly go from bad to the worst.

What he said ^^^
From the Wikipedia article cited: "The affinity between hemoglobin and carbon monoxide is approximately 230 times stronger than the affinity between hemoglobin and oxygen so hemoglobin binds to carbon monoxide in preference to oxygen." It's similar to Count Dracula - it LOVES your blood!

 

[laser3kw]

thanks for the thoughts. All points well taken.
Believe me this isn't my first rodeo. We were taught as kids about the dangers of running a car indoors. That's how people commit suicide after all. My history has always centered around engine work in some regard. I even worked in several repair shops of varying sizes from lawn mowers to heavy equipment. It was always common to start engines with the doors shut (winter time up north). But we always opened the doors to air it out after a short time. Some places had the hose through the door setup. Not saying its the right thing to do, but it's what was done then.
In this case, I was going to open up the doors after I finished draining the gas and few other details. What is really a surprise is how long the detector continued even after I opened the place up and aired it out. I had both the overhead door and the walk in door open for several minutes. And the detector still went off (it quit eventually).

I am now a little more aware of the build up of CO.I always knew it was there, just not how much. I am going to look for a detector that has a digital readout that shows the level, even if it not a critical level.
And maybe this summer, when I get a heater installed, I will put a power exhaust fan for added help.

 

[Bull]

I have a CO detector mounted at around chest height, and I mainly heat my 24x32 garage with a torpedo running on diesel. The meter never registers anything from that heater. Why is that?

It certainly does register quite a bit if I run a car engine in there, even with the door cracked, so I know it isn't broken.

 

[southalabama]

I've got a friend who committed suicide by carbon monoxide.
At that time I read a lot about it.

After the hurricanes of a few years back carbon monoxide from generators killed several people within the storm zone.

Glad you had the warning and the intelligence to understand what it was telling you.

 

[Jlbc212]

I have a CO detector mounted at around chest height, and I mainly heat my 24x32 garage with a torpedo running on diesel. The meter never registers anything from that heater. Why is that?

It certainly does register quite a bit if I run a car engine in there, even with the door cracked, so I know it isn't broken.

The torpedo heater may be consuming oxygen at a lesser rate than the air filtering into the garage, whereas the car engine, even with the door cracked, may be consuming more. The greater danger with a torpedo heater is when people run it with it sitting on the garage floor if there are any flammable liquids or gases stored in the garage. Just about all of the vapors of these materials are heavier than air. Some vapors, like gasoline, are easily ignited.

 

[Tader82]

Howdy new here, but I'm a licensed (in Texas) for home/business fire and alarm Tech(retired). As stated CO is the same weight or so of air. With that said there is NO set height the sensor is to be set at, instead you place a sensor next to (I prefer no more than 3 feet away) the source of the object that can produce CO. If it can be done put it right next to the device.

In my own home i have three CO sensor. one 2 foot from the gas dry, in the hall about 3 feet from the gas water heater/HVAC system , and the last is a high heat tolerant one in the attic right next to the gas HVAC system.

This is because you do not want to WAIT for the gas to get to you, if the CO generating device is on the other side of the house from you it will fill the house full before it get to you . Now the whole mass of the air in the house will be over saturated with CO and be very bad for you and the family.

Hope this helps with anyone wanting to know.

 

[Stevie-Ray]

I almost died from CO poisoning when I was a kid. I was at my friend's sister's house, 4 of us, and we all had slight headaches. After his sister and her husband got home, she noticed a very slight strange smell in the house. Not wanting to take chances, they stayed the night at another sister's apartment, and we all went home as usual. Come to find out the heat exchanger in their furnace went out, along with other furnace problems, that was causing the odd smell. (Likely the burning of particles that were, before the problem, out of reach of flame) We were told that had we fallen asleep, we likely wouldn't have awakened. Scared hell out of me, and consequently, I've had CO detectors in my house, ASAP. Have 2 right now, one in the family room and one in the bedroom. I'll be getting a third for the utility mud room.

What was said about today's cars is true. There have been reports of attempted suicides using new cars, and people waking up after a nap with their cars still running, but very much alive.

 

[jaye944]

Well ****** me, I was going to argue, as I was always told to put it at floor height

Where To Install A Carbon Monoxide Alarm
Since carbon monoxide moves freely in the air, the suggested location is in or as near as possible to sleeping areas of the home. The human body is most vulnerable to the effects of carbon monoxide during sleeping hours. To work properly the unit must not be blocked by furniture or draperies. Carbon Monoxide is virtually the same weight as air and therefore the alarm protects you in a high or low location.

For maximum protection, a carbon monoxide alarm should be located outside primary sleeping areas, in sleeping areas and in each level of your home.

source: http://www.oafc.on.ca/carbon-monoxide

Ontario Associatio of Fire Chiefs !

- See more at: http://www.oafc.on.ca/carbon-monoxide#sthash.shDK010w.dpuf

No!

Air is mostly N2. 14x2=28
CO has a MW of 12+16=28

CO has the same density as air (or close enough for all practical purposes).
Best practices with a CO detector is to put it at a convenient height. Since I have ones with a digital display, I prefer eye level.

The danger from CO is that it binds to the hemoglobin in your blood better than oxygen, so you die from oxygen deprivation. It also takes a lot of time for the CO in your blood to be released. So it is dangerous both at high concentrations over a short time period, but ALSO at relatively low concentrations if exposed for a longer period, because it can build up in your blood.

https://en.wikipedia.org/wiki/Carbon_monoxide_poisoning

As the concentration increases, the amount of time you can survive exposure decreases.
But there is a big catch here. Engines and unvented heaters produce more CO as they run richer. In the case of combustion inside starting with fresh air, the engine/heater consumes oxygen, and produces CO2 (as well as some CO as a product of partial combustion, among other things). As the O2 concentration in the air goes down, and the CO2 levels go up, the exhaust will produce increasing amounts of CO. So, while it may not start out too bad, things can quickly go from bad to the worst.

 

[Coloshaver]

That's about right for a small engine. The cars built since the mid 90's burn so clean that if you had a 100 mile commute and then cranked your lawnmower up. You just made more pollution just starting the mower than you did in the 100 mile drive. The exhaust coming out of the modern car has less CO than the air that went in the air cleaner.

A couple years ago, I was working on a '73 Ford pickup. It was cold out so the shop doors were closed. I started it up just to be sure it would run. It couldn't have been more than 2 minutes before I shut it down. I have a 1500 sq ft shop with a 16 foot ceiling so there is a lot of volume. I went inside the house for lunch and came back out to work on it. The first time I stood up, I felt a little dizzy. Within about 5 minutes, I felt staggering drunk and had severe tunnel vision. As a former EMT, I immediately thought about CO, opened the overhead door and went back inside the house. I made it as far as my front hall and passed out on the floor. I was out for over 30 minutes in fresh air.

I installed a detector the next day and never ran the old truck without my overhead door wide open. Since then, I have occasionally run new cars on my lift (I do open the door), but the CO detector stayed locked on "00"

 

[theoldwizard1]

The Pro-Stream 70,000 BTU Kerosene/Diesel Radiant "Sun Stream" Heater - Amazon $300 has gotten very good online reviews. It is much quieter than most torpedo/hot dog heaters. It also emits less CO and CO2 than most heaters.

 

[Mattlt]

Is it possible you bought a new old stock detector? Look for a date on the detector itself, usually very small print on the back. Most are only good for 5-7 years.

We find a lot of ghost trips when detectors reach their end-of-life, even with new batteries. Usually at 3:00 am...

 

[brycez28]

The other day I was walking past my garage and heard my carbon monoxide detector doing off. It was odd because I hadn't run any engines in my garage. I don't have any gas lines going to the garage and my 20lb propane tank was empty (and closed) from previous weekends use. A few hours before I had my atv running outside the garage door, with the door open to pull my trailer out of the garage. I was in the garage for a couple hours after that and it never went off. Took it outside, pushed reset, went back in the garage and didn't go off anymore. From the comments above, I should check the date on it. It is "Kiddie" brand from Menards, bought about 3 months ago.

 

[nehog]

...
After the hurricanes of a few years back carbon monoxide from generators killed several people within the storm zone.
...

Prediction: The New England blizzard for tomorrow (1/27/15) will result in power failures, and at least one person will die from CO created from a generator run on a back deck, a garage, or somewhere else inappropriate. At least one. Probably more than one.

 

[rlitman]

I have a CO detector mounted at around chest height, and I mainly heat my 24x32 garage with a torpedo running on diesel. The meter never registers anything from that heater. Why is that?

It certainly does register quite a bit if I run a car engine in there, even with the door cracked, so I know it isn't broken.

CO detectors with digital displays will read 00 until the level reaches an alarm threshold. But you can usually push the button and see what the peak sensed level actually was.

Howdy new here, but I'm a licensed (in Texas) for home/business fire and alarm Tech(retired). As stated CO is the same weight or so of air. With that said there is NO set height the sensor is to be set at, instead you place a sensor next to (I prefer no more than 3 feet away) the source of the object that can produce CO. If it can be done put it right next to the device.

As with smoke detectors, there are two schools of thought on the matter.
Placing the detector where it will detect earliest, or
Placing the detector where it is most needed.

Understand that with CO, unlike fire, it takes time for CO levels to build up indoors. With a working detector, there should always be plenty of time to warn occupants to exit. The minimum threshold for a CO detector is usually with OSHA's 8 hour exposure limit...

What is more important, is raising sleeping occupants, and getting them out in a reasonable amount of time. This is why it is recommended to place your first CO detector near the main sleeping area. A second detector in the boiler room wouldn't hurt, BUT, in my house, there is no way I would hear a detector going off in the boiler room, while I am in my bedroom (this is why code requires fire alarm systems to link smoke detectors...).

Also, note that placing a CO detector next to a potential CO source is not necessarily going to give the fastest alarm. With the example of a cracked heat exchanger in a furnace, the CO would be blown out into the ductwork, and be seen in the house BEFORE the area around the furnace.

The Pro-Stream 70,000 BTU Kerosene/Diesel Radiant "Sun Stream" Heater - Amazon $300 has gotten very good online reviews. It is much quieter than most torpedo/hot dog heaters. It also emits less CO and CO2 than most heaters.

CO2 emissions are directly related to the carbon content of the fuel, and the BTU output.
Natural gas has less carbon than propane, which has less carbon than diesel.
CO emissions are not as directly related, and catalytic heaters do indeed have very low CO output. If I were shopping for an unvented garage heater, one of those would be on the top of my list.

Prediction: The New England blizzard for tomorrow (1/27/15) will result in power failures, and at least one person will die from CO created from a generator run on a back deck, a garage, or somewhere else inappropriate. At least one. Probably more than one.

It is sad to say that you are probably right.
Though indoor use of heaters and heart attacks from shoveling are usually the big winter storm killers.

 

[laser3kw]

I bought the CO detector out of concern about the propane heater. I got a side benefit when it warned me of exhaust emission.
both are good reason to have one in your garage.
The question I have is the instructions say the range is 40º to 100º.
I wonder how effective it is at 20~30º? before my shop warms up?

 

[Zrexxer]

Well today it went off! Not from the heater, but because I finished off a rebuild of a Tecumseh snow blower and was tuning the carb. I did the first fire up and was tweeking the carb and let it run for about 20 minutes to get a good heatup.

I can't quite wrap my mind around the fact that after you ran an engine in an enclosed shop for 20 minutes, your first thought was that the CO detector was malfunctioning...

Having a detector is a good plan, but it can't replace being smart about what you're doing. You need to know that running an engine in an enclosed space will kill you, and not rely on a detector to warn you that it's about to become too late...

 

[cactiki]

CO is no joke. Just a few weeks ago my former boss was running a chain saw in his garage cutting some wood. His wife found him dead. I sure would not want to do that to my wife and kids.

 

[Jack Olsen]

I recently got two of these for my kids' rooms, after having some issues with our (aging) furnace. I haven't gotten any reading at all on them so far. But recently, I moved one out to the garage. I've got no catalytic converter on my weekend car. I was surprised by how quickly the levels go up after just starting the engine and almost immediately turning it off. If I leave the doors closed, the alarm will eventually go off. The whole-garage fan brings the level back down quickly. But I'm keeping the thing out there.

FYI:

Concentration (parts per million) Symptoms

35 No adverse effects within 8 hours.

200 Mild headache after 2-3 hours of exposure.

400 Headache and nausea after 1-2 hours.

800 Headache, nausea and dizziness after 45 minutes; collapse after 2 hours.

1000 Loss of consciousness after 1 hour.

1600 Headache, nausea and dizziness after 20 minutes; unconsciousness after 30 minutes.

3200 Headache, nausea and dizziness after 5-10 minutes; unconsciousness after 30 minutes.

12,800 Immediate physiological effects; unconsciousness and danger of death after 1-3 minutes.

Source: U.S. Consumer Product Safety Commission

 

[NUTTSGT]

Is it possible you bought a new old stock detector? Look for a date on the detector itself, usually very small print on the back. Most are only good for 5-7 years.

We find a lot of ghost trips when detectors reach their end-of-life, even with new batteries. Usually at 3:00 am...

Generally we the same calls for the old ones in the early morning hours. The others are the ones about 11pm. The detector has been going off all day and they keep resetting it. They only call us because they don't want to go to bed with it going off yet they spend the entire day with it randomly going off.

Like Matt said, check the date on the back. If it's 7 years old, we recommend buying a new one. When it starts chirping, read the back and see what the directions say. It may not be alerting for a CO issue but low battery or end of life.

Nighthawk makes a plug in (btry back up) detector with a digital readout. It'll be more expensive but might be worth it in your own case.

 

[laser3kw]

I just got another CO detector with a digital readout $59 at Menards.
I spent the day in there (30 x 40 x 12) with my propane construction heater running at 30k btu for almost 6 hours. I checked the read out and it showed a "11" (ppm). barely more than a busy street corner.
But then yesterday I went in and fired up the snow blower (no heater running). It coughed and sputtered on choke setting for a minute and then I cleaned it out and moved it outside the garage - maybe a total run time inside of 3 ~4 minutes. CO detector measured 14ppm.
propane heater 11ppm - 6 hours
snow blower 14ppm - 3 minutes
Good to know..

 

[Joe69]

I work for a paving contractor. One of our estimators came in the shop last winter, wanting to borrow a Stihl concrete saw for the weekend. I told him that was fine, until he told me that he wanted to cut the floor in his basement. Can you imagine, 2 cycle exhaust fumes and concrete dust? I explained the dangers to him, and he rented an electric saw. Trying to save a buck could've cost him his life. I'm just glad he told me what he was planning to do before he left with the saw.

Joe

 

[Denwood]

If you have interconnected smoke alarms, replace them with combination smoke/CO. The Kidde units talk so you know which type of alarm is being indicated.

We have 3 levels to cover, so furnace room has one detector, basement hallway, main floor central, and upstairs outside our rooms. All hell breaks loose when testing as all four go off together. It was a pain during renovation to do new wiring for them, but glad we did. All four also have battery backup and retain interconnect on battery operation as well.

You can interconnect up to 24 units: http://www.kidde.com/home-safety/en/us/products/fire-safety/combination-smoke-co-alarms/kn-cosm-iba/

Wish I would have interconnected my shop when running gas and LAN out..

 

[G_P]

I almost died from CO when running a supposedly safe tent heater in a tent with a small vent open. Turns out it wasn't as safe as the label on the box made it out to be. Scared the hell out of me.

I would never run a gas engine in an enclosed shop for more than a minute or two. CO is nasty stuff and can creep up on you quickly.

 

[turbozombie]

I can't quite wrap my mind around the fact that after you ran an engine in an enclosed shop for 20 minutes, your first thought was that the CO detector was malfunctioning...

One of the symptoms of oxygen deficiency I was taught to look for is "reduced cognitive ability". Basically it makes you too stupid to realize you're now stupid.

 

[Falcon67]

I have - had - a Kidde CO detector in the shop. Threw it out. Once it went off, It'd never shut up. So some brand recommendations might be good. I never run any engine in the shop without windows fans and doors open.

 

[Jlbc212]

I was using an oxy-acetylene cutting torch to cut a piece of 3/8" steel plate for a new workbench. I made a 60" cut. I wasn't paying attention to the amount of time it took me to make the cut (maybe a couple of minutes?), but when I turned to look at the CO detector I have mounted on the rear garage wall it read 100ppm. My garage is just under 1000sqft. with a 12ft high ceiling. Nothing else in the garage was running or on, except the overhead flourescent lights.

 

[bd8134]

I have this one on the wall next to the door in the garage.
http://www.amazon.com/Kidde-KN-COPP-B-LPM-Battery-Operated-Monoxide-Digital/dp/B004Y6V5CI/ref=cm_cr_pr_product_top
It is a bit of a pain to reset the max level but works well. Even reversing modern cars comes up with a reading even though it is low. My non-cat car I have to drive in to minimize the smell and CO levels. I remember as a child my dad reversing his Rover V8 into a tiny garage and the smell was terrible. How stupid we were, it is funny how a bit of edulacakion helps.