LBNL has developed software tools that assist in the development of AERC’s certification process.


AERCalc is used to calculate the annual energy performance of window attachments. The program allows a user to import windows with attachments from a WINDOW database, specify the air leakage values for specific products such as window panels, calculate the annual energy performance for heating and cooling based on EnergyPlus hourly simulations, and export the results. AERCalc Download


WINDOW is a tool for analyzing window thermal and optical performance. This software enables analysis of products made from any combination glazing layers, gas layers, frames, spacers, and dividers under any environmental conditions and at any tilt, and can model complex glazing systems such as venetian blinds and roller shades. WINDOW Download


THERM is software for analyzing two-dimensional heat transfer through building products. LBNL developed THERM for use by building component manufacturers, engineers, educators, students, architects, and others interested in heat transfer. Using THERM, you can model two-dimensional heat-transfer effects in building components such as windows, walls, foundations, roofs, and doors; appliances; and other products where thermal bridges are of concern. THERM’s heat-transfer analysis allows you to evaluate a product’s energy efficiency and local temperature patterns, which may relate directly to problems with condensation, moisture damage, and structural integrity. THERM Download


EnergyPlusTM is a whole building energy simulation program that engineers, architects, and researchers use to model both energy consumption for heating, cooling, ventilation, lighting and plug and process load and water use in buildings. EnergyPlus Download