I'm assuming that you're in US/Canada, in which case there would be two hots at 120V each. These are out of phase and are cumulative to 240V, but they can NOT be combined together without a load. That would be a short.
It can be cheated by putting the two hots on a three-prong outlet, abandonning the neutral, and using the ground as normal. This would be 120+/120- or balanced 240V (or close to balanced). Electricians might not be willing to do "bend" the code and your insurance could be void if there were a problem. I usually suggest using GFCI protection for DIY balanced AC.
Europe has 240+/0- unbalanced AC. Technically 220V, but that's splitting hairs.
It can be cheated by putting the two hots on a three-prong outlet, abandonning the neutral, and using the ground as normal. This would be 120+/120- or balanced 240V (or close to balanced). Electricians might not be willing to do "bend" the code and your insurance could be void if there were a problem. I usually suggest using GFCI protection for DIY balanced AC.
Europe has 240+/0- unbalanced AC. Technically 220V, but that's splitting hairs.