Carbon monoxide is in the smoke?

[AndersMJ]

I'm almost done with my chimney and all that. The three things to look out for is 1) carbon monoxide, 2) carbon dioxide and 3) smoke, as far as I can read. The carbon dioxide I reckon will be no problem because my shop is so ventilated by small holes everywhere and I plan to keep the sliding door half open.

My question now is, the smoke and carbon monoxide is supposed to leave through the chimney... Since the carbon monoxide is odorless and invisible it is what have me most worried. Is it in the smoke or what, cause if it is I guess it's safe to say that if ALL the smoke leaves, then the CO does too...?

Also I plan to buy a carbon dioxide alarm for the shop before lighting for the first time. Does it matter where this is placed?

Hope someone can shed some light on this.

[Jerry W.]

AndersMJ,
Your major concern is the carbon monoxide. You do not have to have smoke to have CO. CO combines with the hemoglobin (the oxygen carrying constituent of the blood) 210 time more readily than oxygen. A small amount of carbon monoxide over a long period of time can still cause major problems. A CO detector is highly recommended as it will alarm before you have a major problem. As a firefigter, over the years I have responded to many of these in peoples residence. They can be a real lifesaver.
Jerry

[Frosty]

First, you're buying a CO (Carbon Monoxide) alarm, CO2 isn't near so dangerous, I don't think CO2 alarms are common if available at all.

When hot the exhaust gasses will head for the roof so a well designed, built and placed chimney should carry the bulk out if your shop is ventilated enough to provide makeup air. It'll even hang near the ceiling till it cools so a CO monitor may not register much till later after you've stopped forging. Then it'll cool and settle to low spots as it's more dense than clear air. When everything is an equal temp it's low in the shop and a direct hazard.

However as long as it's in the shop it's a hazard so keep the batteries up in the detector and keep the ventilation good. There should be placement instructions with the detector but visiting a fire station WHEN THEY'RE NOT BUSY!!! is a good call. Fire fighters are always happy to help folk stay safe, after all they're the guys who're going to have to come rescue you if things go bad. Oh yeah, park well clear of the station doors and driveways so they can roll in a hurry if they need to.

As a rule of thumb (to be superseded by professional advice!) I place CO detectors a few feet off the floor and away from large CO producers like the forge. On the floor it may alert when you don't really need it. However if you have kids or pets in the shop place the detectors lower to cover their breathing zone.

Here's another safety equipment placement tip. Do NOT put your fire extinguishers BEHIND the forge, kitchen range, wood stove, etc. place it close but on the escape route. You do NOT want to have to reach over a fire to get to the extinguisher, nor do you want to encourage someone to trap themselves trying to fight a fire. Placing extinguishers on the escape routes lets folk clear the path to get out if the fire gets out of hand.

Again, read the instructions and ask the pros. The firefighters may tell you to call back another time but they won't blow you off, fire safety is their trade in life.

Frosty The Lucky.

[Frosty]

AND there you go, a professional speaks. Jerry W. is not only a fire fighter he's trains fire fighters so his word is worth FAR more than mine. It's only a matter of timing my reply is here at all.

Thanks Jerry.

Frosty The Lucky.

[AndersMJ]

Thanks for the quick responses both of you. Just realised, I wrote 'carbon dioxide alarm'. Should have read 'carbon monoxide alarm'. :)

[son_of_bluegrass]

CO detectors should be place between 12 and 18 inches from the CEILING (and if memory serves not in a corner and I think there is a distance away from doors and windows). CO is slightly lighter that normal air and will concentrate at the ceiling first. CO2 is heavier than air and will collect at floor level.


CO has a density of 1.165 kg/m3 (NTP) or 1.250 kg/m3 (STP), "normal" air has a density of 1.205 kg/m3 (NTP) or 1.293 kg/m3 (STP). This is taken from http://www.engineeringtoolbox.com/gas-density-d_158.html

ron

Hit the post button but it doesn't seem to have went, if this is a double post - sorry.

[ptree]

Carbon Monoxide is a silent killer. As noted, no smell, and no taste and you can't see it. Mostly comes from incomplete combustion. You do NOT have to have smoke to have CO. IN my factory, we run propane forklifts inside an air conditioned factory. So... daily I walk every aisle of the factory with a CO monitor and measure CO. I also check behind every forklift. Now I DO NOT stick my monitor in the exhaust pipe as my monitor measures in Parts Per Million ( PPM). I hold the monitor at waiste level and about 18" behind the truck and that way I get cool mixed exhaust that does not fry my meter. I do get an indication of the trucks CO emmision.
The OSHA standards are as follows'
Action level is 25 PPM
Permissible exposure limit for an 8 hour day is 50 PPM

OSHA sets Action levels at half the permissible level and the permissible level at half the level known to cause danger/harm.
Whith good truck maintenance we see typical levels in the factory of 2-4 PPM, and I see avergae truck levels of 3-4PPM. A truck that is running badley will peg out the meter at the 250PPM level.
Propane often has residuals from the refinery in the tank, and when the tank gets very low, the exhaust will stink yet most of the time the CO does not increase. Now let those oily goey residuals clog up the vaporizer that uses engine coolant to wrm the propane and force good evaporation to vapor, and not only will the engine run poorly and stink but the CO goes thru the roof as you get poor combustion.

[ThomasPowers]

CO is a particular danger for "smokeless fires", (propane, NG, charcoal). With a coal fire you generally *know* you should *NOT* be breathing that junk; but with the invisible fumes you don't have that "warning".

Also gas forges can re-run the exhaust if you are not careful which sets CO production on turbo overdrive++

I see a lot of posts like "I have a window open in my Garage so I should be able to run my propane forge inside it, right?"

To which my general answer is: "I have two ten foot by ten foot roll up doors along opposite ends of my smithy along the general wind directions in my valley. Also the smithy gables are open and there is a one foot by 30 foot vent along the peak of the roofline and even with that if the wind is slight and you stand down wind of the forge you can breath CO in." (I've gotten a CO headache at a ABANA Affiliate meeting before!)

[AndersMJ]

I guess it's safe to say that if all the smoke is going out then the CO is too?

[Jerry W.]

You can have CO without having smoke. CO is colorless and odorless. The only way to know is to have a monitor or a detector. Something to remember is that due to weather conditions or wind direction today it may draw fine. If any of those change it is possible that it could effect the draw. I would get a detector and err on the side of safety.

[pkrankow]

I guess it's safe to say that if all the smoke is going out then the CO is too?

No, but it is a reasonable assessment. Get some CO detectors and put them in the shop to make sure.

Phil

[AndersMJ]

Thanks for all the replies to everyone. Like I wrote I am gonna get a CO detector for sure.

[ThomasPowers]

Being "overly safe" means that you don't have to keep on worrying about something; but can get on and do stuff!

[AndersMJ]

Being "overly safe" means that you don't have to keep on worrying about something; but can get on and do stuff!

Couldn't agree more, hence I created this as a new topic just to be sure. I considered calling the chimney sweeper to look at it (he's gonna see it anyway next time he inspects the house chimney) and his general opinion about it. :)

[Jim-the-Jedi]

Would using a powered flue help remove the problem - ie a hood and flue with an extraction fan in it

[ThomasPowers]

I tried that once and found every time I tried to forge weld I was overheating the fan.

In my new shop I just have a 10" diameter flue going up at about a 75 deg angle for 10' no constructions, toppers or turns and you can hear the "whoosh" as the fire gets going good. Helps to live where rain isn't much of an issue---in the last 6 months we are still under 1" *total*!