Energy efficient IGUs with polymeric near-infrared reflecting films

Dr. Raghu Padiyath, Dr. Jayshree Seth
3M Company

With the increased awareness and need for energy efficient windows, the use of sputter coated low-e glass within insulated glass units (IGU) is on the rise. These coatings, referred to as "soft coatings", are applied to glass using complex vacuum deposition machinery and highly sophisticated control schemes to ensure performance and uniformity. IGUs made from sputter coated glass are ideal for both heating and cooling dominated climates since they can have low U-value as well as low solar heat gain coefficient. The downside to such coatings is their low scratch resistance. Pyrolytic low-e coatings, referred to as “hard coatings,” are comparatively easier to handle due to their improved scratch resistance and easier to produce cost effectively, but are most beneficial only for heating dominated climates.

This paper discusses the use of new polymeric, clear, near infra red (NIR) reflecting film technology in combination with pyrolytic low-e coatings for a cost effective IGU solution with significant improvement in solar heat gain coefficient and negligible impact on appearance or visible light transmission. These polymeric films may be adhered to #2, #3 or #4 surfaces of a double pane IGU or be used in a suspended configuration to construct a “triple pane” IGU. In addition to being highly efficient NIR reflecting, these films also reflect significantly in the UV region providing additional benefit to the end users. The transmission characteristics of the glazing may also be altered by incorporating neutral or NIR absorbers in the film to further impart glare reduction and solar heat gain reduction.

Full Text Article [116 KB]

The Authors

Dr. Raghu Padiyath Senior product specialist 3M Raghu Padiyath is currently a senior product development specialist at 3M Company in St. Paul, MN. He holds a Ph.D. in Chemical Engineering and has worked on such varied subjects as vacuum thin film p... Read more