Workshop exhaust fans

[Bob in St. Louis]

Hey all,
Curious about an exhaust fan for the workshop.
In my basement workshop, I do a fair amount of wood working, painting, staining, a (very small amount of) metal working, and am thinking about bullet casting down there too.
Today I spray painted a few things in there, which darn near messed up the whole house. The smell of this paint gave me "the look" from the wife.
I'd like to install an exhaust fan (or two?) to help keep the nasty stuff out of the house.

So those are the uses of the shop. It is 12' x 19' x 8.5' tall and in the basement. I've got access to the sill plate area, so I can poke a 4", 5", or 6" hole without a problem. I'd like to know what you guys are using, and the CFM you're talking about.
Thanks in advance fellas.
Bob

[rancher1913]

around here we pick up mary jane grow operation fans, they are in line and quiet. craigslist almost always has a bunch from a remodel. don't know about explosive vapors thru them, might be dicey but an explosion proof fan will set you back a good bit.

[Bob in St. Louis]

I actually google searched that, and was surprised to see actual fans for sale!?!?
But "explosion proof", isn't needed for my operation, nor is the mary jane aspect.
Although, if your area has an excessive amount of them, maybe you'd be so kind as to help me out with a purchase.

Seems the prevalent drug of choice in my area is meth and heroin, so no fans needed, I guess.

[CastingFool]

See if you can pick up a blower and motor taken off an old furnace. they can move a lot of air, and they are relatively easy to mount.

[frkelly74]

I use the fan off the top of an old AC unit that was on the house when we bought it. The system was old and not holding refrigerant but the fan still runs. I took out a window and framed in for the fan and mounted it on the outside. It is 240 volt and will move some air. Kind of noisy though.

[dverna]

The issue is you need make up air. If you live in a cold climate, the air you suck in is cold and will cause a heat load. Same issue if it is hot and you use AC.

If if I was setting up an indoor casting bench, I would look at a fume hood and run two ducts. Exhaust and supply.

Don Verna

[runfiverun]

your room is about 1800 square feet.
anything that moves 100 cfm out would completely clear a volume of whatever in there every 18 minutes. [the throttle body on my mustang would do it in under 2 minutes]
you'd have to make up the hot or cold air in that amount of time.

just the smoke off a casting pot would suck right out, taking about 1/4 the areas heat with it through a 4" pipe with an exhaust fan and a hood [from a kitchen] in about the same time.
don't get too carried away with CFM it's more air than you think.

[Andy]

You can get a brand new 6" centrifugal "in-line" style fan pretty cheap due to all the potheads creating a demand for them for whatever it is they do in their basements/attics. I bought one on ebay for a woodstove heat recirculating thing I did and only realized this once the box came in with a pot leaf as the company logo (great business practice guys), won't be buying from them again.

the fan works great though and a centrifugal fan can push or pull through a lot of ducting without losing as much CFM as a regular in-line blade fan. You can run these fans with a variable speed control for a woodworking router and (as long as you don't turn it down so low it doesn't turn) that works well to reduce the CFM when you want it lower.

So, you could buy one of these setups, pipe it out your sill area and make a hood for it over the table you want to spray finish and cast on. The CFM you want for removing spray is much higher than what you need for lead fumes so the adjustable nature of this option gives you a good compromise solution. You're probably looking at about $150-200 to do this correctly depending on the deals you find.

[shredder]

[the throttle body on my mustang would do it in under 2 minutes]

I would love to drive your mustang!!

[Handloader109]

I have two blower fans on my wood fireplace that circulate air. Each has simple control that is in reality a light dimmer. Works fine. Id go to your local hvac installer and see if they have or would hold you a used blower from a dismantled/replaced unit. Maybe $20$30 tops. Maybe even free, control is about $10-15 make sure it can be used for induction use. Orange or Blue stores have them. Build hood, and turn low for casting, just want to take fumes out. Lacquer will require high speed! If you need makup air, small vent could be installed. I use a 200 cfm blower for my laser exhaust and makeup is needed every now and then. I can pull smoke back in from an unused stove in the basement that has its chimney next to main fireplace. Only happens in no wind and high humidity, but i do watch for it.

[Hickory]

Here are some ideas.

https://www.amazon.com/s/?ie=UTF8&ke...l_44ja13qwzb_e

[rancher1913]

if you find one let me know, I can pick up and ship if needed.

[castalott]

But if you run hot exhaust gases ( think smoke from fluxing and such) thru a fan with plastic bearings ( yes, some are) , the bearings will melt and the fan will go 'kaput'. Ask me how I know this.... I suggest a better way is not run any exhaust gas or heat thru any bearing or motor... keep the bearings and motor outside the air flow.

Dale

[lightman]

I have a 36 inch fan built into the gable end of my shop with louvers that open when I start the fan. I think its 1/3 hp. It will suck out the smoke from my welder or when I'm smelting dirty wheelweights. These are not terribly expensive but do require some work to install. I also have a 48 inch fan that I can roll around that moves probably even more air. Depending on the quality, they run from $200 to over $500. My shop is only heated with a portable heater and has no A/C, so thats not a problem.

[Bob in St. Louis]

Great ideas fellas, thank you. This is giving me some food for thought. I hadn't thought about adjustability for various needs either, I was thinking about a simple 'on' type fan. Great idea. Good information, thank you all. Looks like I've got some shopping to do!

[Echo]

I surely like the idea of intake and outlet vents. Maybe run a piece of dryer hose from the intake vent toward your work bench, with the fan sucking from above and blowing out the outlet - maybe?

[Bob in St. Louis]

What might be a good idea.....
Have two fans.
If I don't need much CFM, have one as "intake", and one as "exhaust" in the workshop. This would mean the shop is self contained, and separate from the rest of the house.
In the case where I need A LOT of CFM, have them both as "exhaust", and use a window elsewhere in the house as the intake. This would then require the rest of the house be part of the equation, as it would have to supply the "intake" part.
That would ensure none of the "nasties" would enter the rest of the living space.
That make sense?
Thoughts on that?

[higgins]

I don't have an exhaust fan, but if I decided to install one, I would contact the local remodeling contractors and see if they have a range hood they've taken out because it's the wrong color, wrong metal, or just looks "dated".

[Geezer in NH]

I would love to drive your mustang!!

[Bob in St. Louis]

I thank you fellas for all the advice. Here's what I ended up buying.
Since we all like a good pictures of a workshop, I'll be sure to take a photo or two of the final product installed.
Thanks again!

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1