Low-e squared

[menancyandsam]

I'm looking into replacing my windows which are next to my piano.  The current windows are single pane & I have to close to the curtains to keep the sun/heat off the piano in the morning.

Apparently, windows now come with this low-e square option which cuts the heat transfer down considerably, but still allows for the same amount of light to transfer in.  This was demostrated by hold a heat lamp next to a sample of regular dual-glazed glass & a dual-glazed low-e squared glass.  By putting your hand against the other side I noticed that the regular glass was extremly hot & the low-e squared glass had only a barely noticable heat gain.

Does anybody have any experience with low-e squared glass?

Is this type of glass enough for me to keep my curtains open & allow the light to come through?

I live in So. Calif.