Venting system for welding fumes in the shop

Have an idea for making a venting system in the shop for getting rid of welding fumes. I have an outlet Im planning on using in the floor for part of it. Originally I was going to put a water hydrant in so I have a piece of 4" sewer drain pipe through the cement in the floor. What Im thinking of making is a vacuum system similar to a vacuum cleaner to collect and move the fumes outside. I did a small test with a shop vac which did just exactly what Im looking for. Im planning on putting some metal flexible pipe very close to where a person is welding and connect it to the larger pipe for removal. I figure if a person can collect it close enough to the source would help. Can anyone recommend a strong enough fan to install in or near a 4" pipe for such a project? I don't do a lot of welding, just mainly would be used in the winter when the building is heated.

A blower from an outside inflatable bouncy house water slide etc. they move a tremendous amount of air. google pirates of the Caribbean water slide. just a possibility gobble

I will check into that. Thank you for the info. Any idea where the pumps are available for purchase?

I checked on ebay and found a few. Thanks for the input.

If you look for lance's post on fume extractors he mentioned a few points like having enough suction to pull fumes, but not too much that it pulls the gas away (if you are doing mig). Worth a watch of the video.

It sounds like you are trying to get the job done without moving so much air that you cool your shop down. Look into duct blowers or boosters. I think a small one would be perfect for sucking from close to the source.

My exhaust fan that does double duty on spray paint mist works OK.

You mention inside in the winter so likely doors closed and furnace on.
It does not take much of a fan to create negative pressure inside of a building if it is at all well sealed.
Sucking out the pilot light or pulling in exhaust fumes if you are heating with a gas source or wood.
Air make up systems are expensive to buy and operate, in order to move enough air to do a decent job of getting rid of the smoke you will have to at least install a vent or crack a window or door when the fan is running.
Quite a few filtration systems out there to clean the air in welding shops, have seen a few that were nothing more than a furnace squirrel cage fan built into a box with filters mounted on the sides that worked reasonably well.
As they are recycling the air, your heat is not getting sucked out when it is running.

Sounds like you are trying to move as little air as possible. If your willing to move more air, my 12" exhaust fan does a good job for welding along with painting and tractor exhaust. I have an opening to the attic in the rear of the barn with an insulated door over it. I does cool the shop down when running, but in my situation, the attic to the low barn has an opening to the high barn. If I turn the heat in the high barn on for a while prior to the fan, it minimizes this. This fan was easy to install (next to the entrance door) on an existing barn.

If you are planning on filtering or trapping dust, be aware that it is very common to have fires in these systems if you do not keep them clean and change filters regularly.

Regards
Rich

this coming from one who used to live on welder,now not so much but you have to bring in air that you take out or its lost cause. i had 14" pipe in my shop coming and going worked but still get some fumes. i went totally self contained breathing helmet later and boy do i wish i would had it the whole time welding. those boxes with the filters they say they clean the air without loosing heat, had three units in my shop,was total waste of money. but you want to make a nice hood cheap to hook hose onto get you a old 60bu hogfeeder lid thats what i rigged over my main weld table.downdraft table is way better thou. just be careful cause weld fumes can make you sick. btdt.

(quoted from post at 08:25:27 01/19/16) You mention inside in the winter so likely doors closed and furnace on.
It does not take much of a fan to create negative pressure inside of a building if it is at all well sealed.
Sucking out the pilot light or pulling in exhaust fumes if you are heating with a gas source or wood.
Air make up systems are expensive to buy and operate, in order to move enough air to do a decent job of getting rid of the smoke you will have to at least install a vent or crack a window or door when the fan is running.
Quite a few filtration systems out there to clean the air in welding shops, have seen a few that were nothing more than a furnace squirrel cage fan built into a box with filters mounted on the sides that worked reasonably well.
As they are recycling the air, your heat is not getting sucked out when it is running.

Click to expand...

No filter system can take CO out of the air, and that's the main contaminant that will make you sick or kill you.

An exhaust fan with a stack going through the wall inside a larger duct will warm a little incoming air when warm air is being blown out the inside pipe, The longer the larger duct the better, and as long as the exit duct is routed away from the inlet duct you don't recycle fumes.

I weld in an unheated portion of my shop, with a propane radiant heater if I'm out there for a while.

(quoted from post at 09:55:48 01/20/16)

(quoted from post at 08:25:27 01/19/16) You mention inside in the winter so likely doors closed and furnace on.
It does not take much of a fan to create negative pressure inside of a building if it is at all well sealed.
Sucking out the pilot light or pulling in exhaust fumes if you are heating with a gas source or wood.
Air make up systems are expensive to buy and operate, in order to move enough air to do a decent job of getting rid of the smoke you will have to at least install a vent or crack a window or door when the fan is running.
Quite a few filtration systems out there to clean the air in welding shops, have seen a few that were nothing more than a furnace squirrel cage fan built into a box with filters mounted on the sides that worked reasonably well.
As they are recycling the air, your heat is not getting sucked out when it is running.

Click to expand...

No filter system can take CO out of the air, and that's the main contaminant that will make you sick or kill you.

An exhaust fan with a stack going through the wall inside a larger duct will warm a little incoming air when warm air is being blown out the inside pipe, The longer the larger duct the better, and as long as the exit duct is routed away from the inlet duct you don't recycle fumes.

I weld in an unheated portion of my shop, with a propane radiant heater if I'm out there for a while.

Click to expand...

Are you sure that you are getting a significant amount of CO? CO comes from incomplete combustion, you're not burning you are melting except for part of your flux. Heat is high enough for good combustion.