adequate shop ventilation

[Jim S]

I moved my forge into my heated workshop where there are no windows and one door. To vent the forge, I am using a chimney attached to the outside of the wooden building (this is a lined metal chimney designed for a fireplace and previously vented my wood stove which I replaced with an LP wall furnace).

My question is do you think such a setup will allow the coal smoke to exit the building realizing that this winter the one door will be shut. Secondly, I just acquired a gas forge which I thought I might use when I did not have time to fuss with the fire and would place it in the coal forge using the drafting abilities of the chimney to exhaust the carbon monoxide. In this latter scenario, I do not want to find myself passed out on the floor from CO poisoning.

All of the forges I have ever used were in drafty uninsulated open air barns and thus concerns for poisonous gases contaminating the air were moot. However, when it's -20 F, my desires to smith go south and I thought this idea would allow me to work in the winter. Your opinions, criticisms, and insults would be appreciated.

Jim

[trying-it]

Number 1, where are you located?

Number 2, even in the best of circumstances Mother Nature has a way of playing tricks with draft/chimney draw. There are smoke and CO2 detectors available. A just-in-case exhaust fan system might come in handy occasionally. Exhaust fans also come in handy if you decide to do some type of welding inside too.

Just my $0.02 worth.

BE safe and have fun.

[trying-it]

OOOPs, meant to type - smoke and CO detectors.
Guess some of that subject matter from those chemistry classes is still lurking within my brain cells someplace; CO = carbon monoxide, CO2 = carbon dioxide.

[Glenn]

The design of the forge, the chimney, the tightness (air infiltration) of the building, all must be considered. When you add a gaser, you compound the problems. Is the shop 8 x 12 feet or 80 x 120 feet in size? Where are you located that it gets -20F? There are too many variables.

A chimney is designed to move smoke / gases out of the building and to the outside. You can see the amount of smoke that leaves the top of the chimney. That same volume of smoke that leaves the building through the chimney MUST be replaced by outside (cold) air coming into the building.

As to the amount of CO or smoke present in the work area, get a CO detector and smoke detector. They are only guide lines. Batteries and equipment have been known to malfunction and fail. If you feel any discomfort, or anything strange, leave the area and get to fresh air immediately.

[ptree]

You have little to no chance of finding yourself laying passed out on the floor from Carbon Monoxide, as you will very probably never ever wake up!

Get a CO monitor. Set up a cross flow ventalation that will supply the make up air for what goes up the flue. Better a little cold from a draft than dead.
Remember that CO is colorless, tasteless, and has no odor. It is a quite killer that suckers you in. Once CO is in the blood the Hemoglobin in your blood likes it better than oxygen and sort of refuses to give it up. You can get over exposed to CO, be found, be awake and placed on 100% O2 and still die.

[Jim S]

Thank you for the replies. I live in Central Illinois where the temperature is fairly mild in comparison to other places where I have resided, but does get to minus 20 F for a time. My shop is 25' by 25' and today I will purchase a CO detector and will consider a smoke detector. My experience with the latter is the xxxx things go off if you light a cigarette. I suspect my solution is not a good one and appreciate your responses. The CO detector will probably be a wise investment that will determine quickly what to do.

I wonder if a fan in the system would help evacuate nasty gasses. What kind of fan and how should one insert same into the exhaust system?
Jim

[trying-it]

Where in Central Illinois? I'm northern edge of southern Illinois, near Nashville/Pinckneyville region. Having a hammerin here Aug 15, 16, 17.

[Glenn]

will consider a smoke detector. My experience with the latter is the xxxx things go off if you light a cigarette.Jim

You complain because they work?

[Rob Browne]

If your forge is near a wall I would be placing a small vent in the wall behind the forge. That way the cold air would be drawn in past the forge and heated a bit.

You must have good ventillation, all the detectors in the world will only tell you that you have a problem, not fix the problem.

[civilwarblacksmith]

Depending what you building is made of, I would put some kind of windows in. You say it's too cold in the winter to forge, you'll also find in the summer it will be too hot to forge once you get the fires lit.

look at getting some vents in the eaves also.

[philip in china]

You really MUST look at this carefully. I would try a really smokey fire deliberately and see where all the smoke goes. (This assumes that smoke is allowed where you are). I have been fortunate in always working in well ventilated (read open sided and cold) shops.