Picking the wrong one could have a major impact on heat and cooling costs. This energy is either absorbed by the glass, reflected back to the outside or transmitted into the building. Far infrared energy is heat radiated from objects. Originally, low-e was intended to reduce heat loss by blocking heat radiating from objects inside the house. This is called far infrared energy.
Solar heat includes energy from visible light and invisible heat called near infrared radiation.
While solar heat gain is helpful for some buildings, it's a problem for others. Blocking solar heat gain has been important in commercial buildings for decades. You've probably seen the bronze, mirrored office towers. Those windows block much of the sun's heat, but also much of the light and views. Selective glazing allows more visible light to penetrate.