How important is "Low-E" in a door if it already has the energy star approval on it?

I'm pricing french doors and yesterday, at Home Depot, the ones I like have the Energy Star approval, but it costs a lot more for the Low-E glass. The sales person said the Low-E probably wouldn't make a big difference.How important is "Low-E" in a door if it already has the energy star approval on it?Hi, low-e glass is only important if you doors are exposed to full sunshine all day long. Energy star is mainly given to items that keep out the cold or heat not the sunshine, thats where low-e comes into play.