Double pipe heat exchanger sizing software (DHex) is a tool that is made to demonstrate the chemical design calculations of Double Pipe (hairpin) Heat Exchangers.

The software will do all the thermal calculations involved in the design and will generate a summary of all results.

Main Functions:

Software Features

• Support S.I Units and English (U.S) Units of measurement.
• Units converter includes 23 measurements units with 200-unit conversion
• Ability to import properties to Hot/Cold sides from Microsoft Excel.
• Add your own Nusselt correlation
• Save/Load results
• Water and Steam properties


• Ability to calculate unknown Cold or Hot side temperatures. Unknown exit temperatures on both sides or any two temperatures on both sides
• Unknown Flow rate on either hot or cold side
• Perform thermal analysis for bare tube double pipe (hairpin) heat exchangers.
• Perform thermal analysis for finned tube double pipe (hairpin) heat exchangers.
• Choose from Counter Current or Co-Current Flow arrangement
• Choose from Series arrangement or Series-Parallel arrangement.
• The software will also tell you the location of Hot/Cold fluids within the heat exchanger (Inner Pipe or Outer Pipe).
• Select from different correlations to calculate Cold/Hot side heat transfer coefficient. Also, the ability to adjust Nusselt number if you do have a different correlation.
• Calculate the Area, Flow area, Length, Log Mean Temperature Difference, Number of Hairpins, Unknown Flow rate.
• Calculate the scale resistance (dirt factor), Equivalent Diameter.
• Calculate Inner Pipe/Outer Pipe (Annulus) side Reynolds, Nusselt numbers & Prandtl Numbers.
• Duty Calculation, Clean and Design Overall heat transfer coefficient calculations
• The ability to define the Duty also the ability to define the heat transfer coefficient on either side.
• Inner Pipe/Outer Pipe (Annulus) velocities and Mass velocity calculations
• Number of Transfer Units and Thermal Capacity ratio calculation.
• Clean and Fouled Fin Efficiency calculations for finned tube heat exchanger.
• Pressure drop calculations & Entrance and Exit losses.
• Pumping power calculation.
Included databases
• Estimate the Physical properties of pure components for more than 1450 fluids; the database has the ability to estimate Thermal Conductivity, Density, Heat Capacity and Viscosity. The database also included critical properties, boiling and melting points and come as a standalone interface but easily integrated with the software.
• User database functions to allow user to add/delete fluids, pipe sizes and heat transfer coefficients and load to hot/cold side (Empty database!).
• Fouling factors
• Plot temperature profile for hot and cold sides to identify any temperature cross


• Export Results summary to Microsoft Excel Engineering Datasheet format. Save/Load results. Generate/Print a summary of results
• Display multiple cases in results grid
• Export Results summary to .rtf file format that can be opened in Microsoft Word


+ Single phase fluid operations with exception to steam which is supported.
+ Single tube units, multi tubes are not supported.

Screen Shots

All screen shots links are available from the screen shots page
Click here to visit the video clip page
double pipe heat exchanger


Click here to download the demo version of the product. Please also note that the demo version of this software will only operate with set examples which are restricted in our demo version.  The full version of this product does not have any restrictions.

We don’t offer a fully working demo version.

Please note: The demo version doesn’t necessary contain all recently added features. To check the latest update history of this software please click here

Click to visit the BUY NOW page

System Requirements

DHex needs the following computer configuration to run:
1. Microsoft Windows operating system
2. 64MB RAM
3. 30MB free disk space
4. Microsoft Dot Net 4.8 Framework

Windows platforms:
Windows 7 SP1, Windows 8, Windows 8.1, Windows 10, Windows 11
32 bit & 64 bit operating systems.