OpenBuildings Pipe/Duct Sizing

I have used Hevacomp Building Designer & Netsys in the past and having tried to purchase the software again understand that it has been replaced with OpenBuildings.

Can anyone advise if the software is anything like the building designer / netsys of old i.e similar in use, better/worse etc... Is it easy to transfer from using one to another or are there big differences/learning curves?

Thanks in advance


  • Hi Jon, 

    Thanks for reaching out! yes, it would not be possible to buy Hevacomp alone. We have OpenBuildings Energy Simulator (a replacement of Hevacomp). Energy Simulator has almost similar funtionalities as Hevacomp and we are continuously developing the product to make it capable of serving our existing and ever extending user base. Builing Design is definitely possible with Energy Simulator, and we are expecting to incorporate the Netsys (pipe and duct sizing) properties within the software by our next update.

    So YES, you definitely can go for OpenBuildings Energy Simulator. Training videos and other wiki materials could be found here. And Surprise! You would be having a free  entitlement of Hevacomp if you purchase OpenBuildings. 

    Hope this clarifies, any queries, we can definitely take a call with you!



  • Just some additional information and clarification.

    The features of the design database from Hevacomp are present in the Energy Simulator part of OpenBuildings Designer and it is possible to do both ASHRAE and CIBSE Calculations.

    As for Netsys and its capabilities.


    OBD allows the user to design in both single line or full 3d mode with the ability to reference (backdrop more file types than Netsys) it has a large library of generic mechanical components and can add component models from manufacturers if needed.

    Pip and Duct Sizing:

    The work for duct sizing is complete and present in OBD. As for Pipe sizing, the algorithms for domestic Hot and cold water are present, but the algorithms for chilled water and gas are scheduled for inclusion in the next release of OBD.

    OBD has a more modern interface and is more aligned to current thinking on UI and 3d modelling. you can see some example learning material below

    Part 1 - Creating a New WorkSet and Model File in OpenBuildings Designer - YouTube

    Brenden Roche

    Applications Engineer

    Bentley Systems, Manchester UK

    This is a test

  • Hello Brenden,

    So in the latest version of OBD ( you can size domestic hot and cold water systems just like in Hevacomp? Can you do so in a simple 2D environment as in Hevacomp?

    Thank you,