Currently, the industry offers low-E on both the #2 surface and the #3 surface. On which surface would you recommend applying the coating to achieve the best solar performance?
Many buildings in Europe are glazed with the low-E coating on surface #3 in order to reflect the heat back into the building as efficiently as possible. Reducing solar factor is most important in commercial buildings where air conditioning costs can be high. Low-E on surface #2 reduces the solar factor but the glazing may appear visually different in reflection when viewed from outside. Typical Low-E coatings for commercial applications are multifunctional coatings of the families SunGuard HP, SunGuard SN and SunGuard SNX. The silver functional layer of these coatings reflects both the longwave heat radiation for a good thermal insulation and the shortwave solar radiation for a good solar protection.
Low-E coating is often on surface #3 in residential applications to achieve a higher solar heat gain and positive energy balance in the colder seasons.