How many glass pans you got? Use 'em all! Even without heat, it will happen - it's the speed in which it will happen - but it will happen.
The more glass pans you got, the quicker it will evaporate only because you're putting less of the solution into each pan. Only if you're leery of added heat, of course!
Live in an area where you have to turn on a furnace? The dryer the air, the quicker the evaporation. Got a dehumidifier? Put it in the room and crank it up.