Re:hmm (Score 1)

Oh my goodness - did I waste money buying those Low-E windows with the Titanium thin layer coating?

Probably not. Consider that the sunlight you'd be shielding against has a blackbody temperature of around 6000K, and then consider how much more quickly heat would get through those windows if there was a 6000K fluid on the other side. Radiation is extremely inefficient compared to conduction or convection, but that doesn't mean it can't transfer a lot of heat in certain circumstances.