LOF – Pilkington Energy Advantage Low-E is the best glass for most applications in a northern climate. It has a very high retention rate of the heat in your home in winter and prevents heat gain in summer. Energy Advantage Glass has a higher Solar Heat Gain Coefficient (SHGC) than Low-E glass designed for southern climates. It provides free winter heat for your home. Since as much as 95% of your energy expense for heating and cooling combined is for heating, this glass is more cost effective than other glass without a high SHGC.