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SUNREL® is a hourly building energy simulation program that aids in the design of small energy-efficient buildings where the loads are dominated by the dynamic interactions between the building's envelope, its environment, and its occupants. The program is based on fundamental models of physical behavior and includes algorithms specifically for passive technologies, such as Trombe walls, programmable window shading, advanced glazings, and natural ventilation. In addition, a simple graphical interface aids in creating input files.

SUNREL is an upgrade of SERI-RES, which was released in the early 1980s by the Solar Energy Research Institute (SERI) that has since been incorporated into the National Renewable Energy Laboratory. The program has been used by researchers around the world and has been proven to be accurate and reliable. SUNREL was developed under NREL's Center for Building and Thermal Systems

SUNREL Wins Award

SUNREL shares a 2005 R&D 100 Award with TREAT software creators for making it easier for building professionals to perform accurate energy audits. Read more in the fact sheet.

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