Psychrometric Chart + Duct Calculator

A convenient, precise and powerful tool for HVAC&R engineers. This psychrometric chart uses 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).

Psychrometric Chart + Duct Calculator v4.4 shareware version


  1. Coordinate system of psychrometric chart is updated to dry bulb temperature and enthalpy;
  2. Add ASHRAE equation support at normal temperature and pressure region, now this psychrometric chart is perfectly consistent with all ASHRAE charts of No.1~7(SI Units) and No.1~5(IP Units);
  3. Water property calculation is updated to IAPWS-IF97 equation;
  4. Introduced real gas effect correlation;
  5. Add functions for grid snap and constant parameter lines at cursor point;
  6. Add grains/lb(d.a) and psia units in psychrometric chart.
  7. Corrected some symbol displays for international language.

Psychrometric Chart + Duct Calculator v3.0 shareware version


  1. Add english(I/P) units support;
  2. Other than eastern style, new western style chart support added in this version, this meets requirements of people who are customed with western style chart;
  3. Add angle reference of process line ratio for enthalpy-humidity and sensible-total heat;
  4. Zoom in, zoom out chart by rolling mouse wheel, and pan chart by pressing middle mouse button and moving mouse;
  5. Add chart toolbar for easily processing chart copy, export, print, pan, zoom, redraw and style selection;
  6. Save and load data function for each data input grid, this is convenient and not need to input data every time restart program;
  7. Option for saving all input data to disk before exit and load them when restarted next time;
  8. Corrected some bugs.

Psychrometric Chart + Duct Calculator v2.0 shareware version


  1. Add process points line and mix point calculating, drawing and managing;
  2. Add wet air point calculating, drawing and converting;
  3. Add constant specific volume and wet bulb temperature line in chart;
  4. Add chart line type, width, color, font properties groups edit and managing;
  5. Add copy(wmf and bmp format), export(Jpg, bmp, wmf, emf format) and print function;
  6. Add language support;
  7. Corrected former bugs.

Psychrometric Chart + Duct Calculator v1.2


Psychrometric chart
  1. Use IFC-67 equation for water/vapor property calculating, and treat air as ideal gas;
  2. Range can be changed, Mouse move point calculation;
  3. Calculate once recycle and twice recycle air flow, summer and winter state;
  4. process line is shown in chart, press UpDown button to see process changing;
  5. Export wmf format file, can be opened and printed by image browser softwareas ACDSee, IE, smoothly zoomed.
Duct calculator
  1. Air and liquid duct;
  2. Calculate duct flow resistance, environmental heat exchange, and adiabatic;
  3. Note: outer coefficient of heat transfer usually is 3~10, >10 when winds.
Download & Buy
For windows, without network and browser limits. Click following button to download the software with 30 days full functional free trial, or pay $65 to get up to 3 license keys.