Adaptive Liquid Crystal Windows
In the United States approximately 30% of the energy used to heat and cool homes is lost through windows. Windows and other glass structures greatly reduce the R-value of walls and result in heat gains in the summer and losses in the winter. It is extremely important to use the best products available to make your windows as energy efficient as possible. While there are numerous reflective window technologies designed to reduce summer cooling loads, they provide no benefit during the winter months.
In partnership with DOE’s Building Technologies Program, AlphaMicron, Inc. is in the process of developing an active window glazing technology that adapts to seasonal climate changes, reducing energy consumption year round. Like many other window technologies, the active window glazing reflects sunlight in the summer months allowing for lower cooling loads. However, the adaptive windows also allow for more sunlight to be transmitted through the window during the winter, resulting in lower heating loads. Further, the technology controls light transmission in such a way that occupants aren’t experiencing an unpleasant interior environment, eliminating factors such as excessive glare or darkness. It also protects interior décor from ultraviolet and solar heat damage.
The technology consists of liquid crystal deposited on a flexible substrate as opposed to glass. Compared to glass, flexible substrates can be especially advantageous in that they offer the possibility of lower production costs associated with streamlined roll-to-roll processes. Flexible substrates are much less fragile than glass, require less heat to coat, and allow rolled-up and compact roll-to-roll production, storage, and transportation. They also open avenues for lightweight and innovative installation solutions. AlphaMicron, Inc. is continuing to develop a roll-to-roll manufacturing process to produce a 14-inch-wide liquid crystal film. Upon successful commercialization of this product, AlphaMicron, Inc. will then scale up there manufacturing process to produce 48-inch-wide films in order to accommodate most window sizes.
Primary benefits from this developing technology include variable transmission for seasonal change (70% in the summer and 30% in the winter), reduction in energy consumption and greenhouse gases by reducing heating and cooling loads, and ensuring a comfortable living/working space without excessive glare or darkness. The technology is versatile enough to be used in both commercial and residential buildings.