Energy Efficient Glass Options   LOĒ²-272 GLASS® We know how important energy efficiency glass is, and our standard LoĒ2-272 glass is a simple means of maximizing your home’s thermal efficiency year-round.  LoĒ2-272 reflects heat back to its source, so summer heat is reflected outdoors and indoor heating in the winter is retained.  LoĒ2-272 also blocks …