You can leave the fan as is and run a 220/230/240 line to the workshop. It's the same type of line as an electric range or electric dryer so you have it in the house. Or check out the link.

Here is a link that might be useful: 220 on 110 lines

i was hoping to just wire it differently if possible..

There are too many variations to give you a definative answer. I've tried trial and error, but error resulted in a smoking piece of junk.
Some motors have alternative wiring schemes on the inside of their electrical connection cover plate. If it's not there, you might try taking it to a motor repair shop for them to look at.

it shows a varaition to make it 200 but not 115.. i have wiring diagrami can post if that helps

It may not be doable on yours, then. If you can find a motor shop, they might know a way.
or
If you know of a local company that installs replacement furnaces, they might have an old 115v fan in their junk pile. (I got two that way)

Are you sure that's not 208/230 volts?

The name plate of the motor will list the acceptable voltages. If 115 isn't included it won't work. Buy a new motor or wire for 240v.

hendricus's link...

is that a real product?!

I built one once... that doesn't mean it was a good idea. What happens when your "120 to 240 adapter" is plugged into circuits A and B, a 240V load is connected, and somebody turns off the breaker for B in order to work on something? The entirety of circuit B remains live through circuit A and the load!

That's a dumb product, and I'm sure that company will eventually be sued into oblivion.

FORGET that idea. Just find a 120V motor or wire properly for 240V.

H'mmm... well, upon reading some of the details of that product, apparently they've prevented the scenario I mention, presumably with a relay or two. I still don't quite trust it, but maybe.