Calculating heating and cooling loads for residential and light commercial buildings has never been easier. The program uses the Manual J method, with enhancements to make the results more accurate and risk free. It operates like a spreadsheet so you get real time loads for every change you make. It a great tool to study any building's energy use profile to determine the best ways to reduce energy costs. Help files have design temperatures for over 400 U.S. cities and all the information you need to make accurate inputs - insulation values for typical walls, roof assemblies, windows, and floors. Once you have all the information stipulated you can experiment with extra roof insulation, attic ventilation, special windows, shading, and many more energy saving ideas. The program calculates a heating and cooling load for each building element, and the air flow needed to satisfy the load. A full analysis is done for both heating and cooling - you can toggle from one to the other by clicking a radio button. All the information is printed out or you can access the form with a word processor and format the results.