Engineering360: "Watch: Liquid-filled window saves energy"

Interesting.

Or you can pull the shades. But this might be more appropriate for where shades are not suitable or desirable. I wonder if the water-based liquid ends up making a bunch of condensation on the 'upper' part of the window?

I wonder how it would handle the cold winters in higher latitudes. No fear of freezing in Singapore is there!

I would rather have a solar (or some transducer) shade, that would also light up the room, as I darken it - by opaque-ing/ closing the shade.

I assume the temperature quoted was the outside pane, what was the temperature of the inside pane as this will determine the heat load on the room.

Air is a much poorer conductor of heat than water so this concept does not make much sense unless something special is happening.