One strategy for reducing building energy consumption is to use beneficial solar gain available through a window, either for winter heating or for daylighting, while minimizing adverse flows. In Berkeley Lab's MoWiTT facility, researchers measure efficient window-and-frame systems to understand the flow of energy through them under realistic conditions.
Consisting of a pair of outdoor, room-sized calorimeters, MoWiTT measures the net energy flow through two window samples in side-by-side tests using ambient weather conditions. MoWiTT characterizes the net energy flow as a function of time and measures the temperatures, solar fluxes and wind conditions to which the samples are exposed.
MoWiTT researchers conduct research to characterize fenestration systems and develop publicly available calculation methods for predicting fenestration thermal performance. Their goals are to assess the performance of energy-efficient windows, to identify opportunities for new development, and to create a knowledge base that will encourage sound selection of optimal windows in the design process.