In this application example the software HTflux is used to assess and optimize a timber-frame window connection. Condensation risks are identified and eliminated. The effect on thermal bridging is measured.

1. Application example
Timber construction detail -
optimization of condensation risk at
window connection
Engineering office - DI Daniel Rüdisser
www.htflux.com

2. HTflux Simulation Software –
extensive information on many levels
DI Daniel Rüdisser / HTflux 2
Materials Temperatures Heat flux Humidity Partial press. Vapor flux

3. DI Daniel Rüdisser / HTflux 3
Example:
Window connection
Initial detail
CAD drawing

4. Thermal analysis
DI Daniel Rüdisser / HTflux 4
Window connection
Thermal analysis
• Thermal bridging calculation
 value
• Minimum internal surface
temperature
(avoid condensation or
mould growth)

5. Condensation analysis
DI Daniel Rüdisser / HTflux 5
Window connection
vapor diffusion &
condensation
3 condensation spots !!
• OSB / facing insulation
• Vapor barrier
• Shutter-box surface

6. DI Daniel Rüdisser / HTflux 6
Window connection
first reflex:
add insulation
(wood fibre-board)
 ineffective, even
counterproductive

7. DI Daniel Rüdisser / HTflux 7
Window connection
Add some timber and
leave air cavity?
works! dry.

8. DI Daniel Rüdisser / HTflux 8
Window connection
Try variations.
Find best constructive
solution.

9. DI Daniel Rüdisser / HTflux 9
Window connection
Try variations.
Find best constructive
solution.

10. DI Daniel Rüdisser / HTflux 10
Window connection
Try variations.
Find best constructive
solution.

11. DI Daniel Rüdisser / HTflux 11
Window connection
Best solution found.
No condensation risk.
Resulting additional heat-
flux is minor.

12. DI Daniel Rüdisser / HTflux 12
Window connection
Final optimized detail.

13. Contact
HTflux - DI Daniel Rüdisser
Ingenieurbüro für Technische Physik
Franziskanerplatz 11
A-8010 Graz
contact@htflux.com
www.htflux.com
DI Daniel Rüdisser / HTflux 13