Ok, I guess I'll need to be more specific.
How much IR light would be radiated compared to a blackbody? I'm under the impression that water vapor is not a very good blackbody, so I'm trying to understand that idea a little better.
I've read that H2O has an absorption/emission band around to 10 micron range. What conditions are required for photons of this wavelength to be emitted by H20 gas? In particular, how hot would the gas have to be? What amount of pressure is required? Under everyday conditions (like steam possible...