PPG Industries’ flat glass business recently announced it has received $312,000 from the U.S. Department of Energy (DOE) to develop a dynamically responsive infrared (IR) window coating that will block heat in the summer to reduce air conditioning costs and transmit solar heat in the winter to reduce heating costs. The funding is part of an award of up to $750,000 being shared with project leader Pacific Northwest National Laboratory (PNNL). PPG and PNNL are designing a coating that can “switch” from a solar IR-reflecting state to a solar IR-transmitting state while maintaining high levels of daylight transmittance in either condition. PPG will provide an additional $78,000 in cost-sharing funds.

The development of such a coating would reportedly represent a major advance compared to current thermochromic window technology, which involves coatings that darken and block visible light when exposed to high volumes of IR energy, and existing electrochromic window technology, which relies on external power sources such as electricity to balance tinting and light transmittance. The new PPG/PNNL coating technology also has the potential to be inexpensive, which would help ensure that dynamically responsive IR windows are an economical option for use in residential and commercial retrofit applications.