|| A convenient, precise and powerful tool for HVAC&R engineers. This psychrometric chart use ASHRAE equations at normal temperature and pressure region and is perfectly consistent with all ASHRAE charts of No.1~7(SI Units) and No.1~5(IP Units). Both Metric(SI) and English(IP) units support. Save and load data function for each data input grid, all input data can be saved for loading next time program started. Psychrometric chart 1. Use IAPWS-IF97 equation for water/vapor properties calculating, and treat moist air as real gas for high precision; 2. Dry bulb temperature and humidity ratio axis range can be changed easily, the chart generation is automatic and fast; 3. Draw protractor for enthalpy-humidity and sensible-total heat ratio; 4. Mouse point catch, snap and calculation, output point information and many air properties; 5. Normal and eastern(China) style support; 6. Chart grid snap, aided constant parameter lines across cursor point, middle button pan and mouse wheel zoom for convenient chart operating; 7. Many process point managements, include point pick up, data input grid, point definition select, point add, insert, reduce, delete, move up and down, open and save point list; 8. Convenient interface for process and mix point calculating; 9. Once and twice recycle calculating; 10. Point state convert calculating, and give warning and error message, output point information if point state is OK; 11. Chart plot/display setup and management support; 12. Chart can be easily printed, copied to clipboard as bmp and wmf format, and exported as bmp, jpg, wmf or emf format. Duct Calculator 1. Calculate air/liquid and round/rectangle cross section duct; 2. Calculate duct flow resistance, environmental heat exchange, and adiabatic effect. Note: Outer coefficient of heat transfer usually 3~10, >10 when winds.