This software is a useful tool for HVAC engineers. Version 3.0 is more powerful and convenient for using. This psychrometric chart use IFC-67 equation for water property calculating, and treat air as ideal gas. So this chart can be used in more large range and is more precise. Both metric and english units support. Save and load data function for each data input grid, this is convenient and not need to input data every time restart program. Psychrometric chart 1. Use IFC-67 equation for water/vapor property calculating, and treat air as ideal gas; 2. Eastern and western style chart support; 3. Draw angle reference of process line ratio for enthalpy-humidity and sensible-total heat ratio; 4. Humidity ratio and bulb temperature axis range can be changed; 5. Chart toolbar for easily processing chart copy, export, print, pan, zoom, redraw and style selection; 6. Mouse point catch and calculate, output point information and many air properties; 7. Many kinds of processing point manipulation, include point pick up, input grid, point definition select, point add, insert, reduce, delete, move up and down, open and save point list; 8. Calculate proces and mix point parameter; 9. Once and twice recycle calculating; 10. Point state convert, and give warning and error message, if point state is OK then output point information; 11. Optional chart ploting setup. 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.