Hot out of the compiler and ready to download now is WUFI Passive 3.5. This update is mostly driven by a few bug fixes, as well as some improvements in functionality and installation. WUFI 3.5 (and newer) will be required for all projects pursuing the forthcoming Phius 2024 CORE and ZERO programs, while Phius 2021 projects may still use v3.3.0.2. This update is free to download for all currently registered users with licenses for WUFI Passive 3.x and newer.

The primary driver of this release was fixing a shading bug in WUFI Passive. The one dynamic element of the otherwise steady state calculation engine behind WUFI Passive is the shading, and this caused an error in calculating the shading factors for windows. 

In WUFI 3.3, the “Calculate WUFI Shading” would disappear after the shading calculation was run, but after some other modifications were made, such as changing orientation, grouping windows, etc., WUFI would not update the shading factors calculated, resulting in a misalignment between the model inputs and the results shown. To fix this, Fraunhofer has added a checksum that is calculated internally to confirm correct shading calculation. No results will be displayed if the shading calculation is out of date, and the run “Calculate WUFI Shading” button will always be present. Feel free to click it as often as you like, but be sure to click before making any major design decisions or submitting the project for review.

Another small fix, a feature-add really, is that WUFI will now check that window reveals will not exceed the size of the window. For example, a 12” wide window with a 6” reveal on the frame used to run, but now WUFI will throw an error if this creates an impossible window as noted in this example.

The built-in source energy target calculator now matches the criteria calculator on the Phius website, and rounds to the nearest 25 kWh/person/yr.

Upon installation of the new version, you may notice that the program is no longer in a ZIP file, but rather just has the installer. This is because the database is now built into the installation file. Only one file to download! 

Please, be my guest and take the new (and likely last) WUFI desktop version for a test drive. As noted above, Phius staff is ready to help answer any questions you may, and the new version will be required for all Phius 2024 projects and newer.

Check out the release notes from Fraunhofer on their website here.