1. Case study: In-Situ Testing and Model Calibration of Interior Insulation Solution for an Office Building in Cold Climate
Paul Klõšeiko, Targo Kalamees
Chair of Building Physics and Energy Efficiency
Tallinn University of Technology
Central Europe towards Sustainable Building 2016, Prague

2. Interior insulation – why?
Mould in corners
Large heat losses
Low thermal comfort
Thermal transmittance of existing structure: U~1W/(m²·K)
1. choice: insulate from the outside!
... but it is not always possible
Photo: Wikimedia Commons / Ivar Leidus
Chair of Building Physics and Energy Efficiency, Tallinn University of Technology

3. Possible problems
Mould behind insulation when eg. mineral wool used without vapour barrier and/or convection occurs
Accumulation of moisture and frost damage in the original structure (especially with vapour tight insulations)
Rotting of wooden beam-ends in wet structure
Increased effect of thermal bridges and mould risk
Reduction of thermal mass
Figure: Fraunhofer IBP !
Chair of Building Physics and Energy Efficiency, Tallinn University of Technology

4. Possible solution
Vapour open capillary active interior insulation systems eg: calcium silicate (CaSi), autoclaved aerated concrete (AAC), ...
AAC
CaSi
Zirkelbach, D., Binder, A. & Künzel, H.M., Kapillaraktive Innendämmungen - Wirkung und Beurteilung. In J. Grunewald & R. Plagge, eds. 1. Internationaler Innendämmkongress Dresden: TU Dresden, pp. 43 – 51.
Plagge, R., Energetic Refurbishment of Brick Buildings. Available at:
Chair of Building Physics and Energy Efficiency, Tallinn University of Technology

5. Case study
7-storey office building (1932) in Tallinn, Estonia, listed by heritage protection
Measurement of indoor temperature and humidity profiles in 7 cabinets
Foto: Wikimedia Commons / Ivar Leidus
Studied rooms
Chair of Building Physics and Energy Efficiency, Tallinn University of Technology

6. Measurement setup
Preliminary HAM modelling and choice of insulation system: autoclaved aerated concrete Ytong Multipor t=50mm on walls, 12.5/20mm XPS on window jambs
Measurement setup:
Chair of Building Physics and Energy Efficiency, Tallinn University of Technology

7. Performance criteria
Saturation sw < 30%sat (sw = moisture content / porosity)
Künzel, H. M ‘Bauphysik der Innendämmung und Bewertungsverfahren’, In Proc. of the 1. Internationaler Innendämmkongress. 2011
Viitanen H., Vinha J ‘Moisture and biodeterioration of building materials and structures’. In Journal of Building Physics, 33 (3)
Künzel, H., Worch, A., et al., Innendämmung nach WTA II: Nachweis von Innendämmsystemen mittels numerischer Berechnungsverfahren (Merkblatt 6-5), 2012.
Chair of Building Physics and Energy Efficiency, Tallinn University of Technology

8. Measurement results
Between insulation and aerated concrete (sensor TRH3):
Min. temp. > -5°C
Max. RH < 95%RH
Performance criteria were not exceeded in any other measured point
2 mild winters and low moisture load – critical situation did not occur
Chair of Building Physics and Energy Efficiency, Tallinn University of Technology

9. Modelling
Static 2D temperature field software for quick assessment of surface condensation and mould growth: LBNL Therm
Dynamic 2D HAM software for detailed calculations: IBK Delphin
1D: aerated concrete; concrete column
2D joints:
Exterior wall betw. windows (hor.)
Exterior wall – AAC interior wall (hor.)
Exterior wall – lightweight interior wall (hor.)
Exterior wall – floor (vert.)
Exterior wall – attic floor (vert.)
Comparison of solutions
Chair of Building Physics and Energy Efficiency, Tallinn University of Technology

10. Vertical detail: exterior wall – attic floor I
Chair of Building Physics and Energy Efficiency, Tallinn University of Technology

11. Vertical detail: exterior wall – attic floor II
5th year of HAM simulation results using Estonian moisture reference years (MRY) as outdoor climate: ?
Temperature
Relative humidity
Chair of Building Physics and Energy Efficiency, Tallinn University of Technology

12. Design process
Determining the original structure, material properties and indoor climate parameters
Preliminary HAM simulations
Field test (in hygrothermally random year)
HAM simulations using measured boundary conditions during field test and comparison with measurement results
If sufficient correlation is aquired: HAM simulations to assess long term performance using hygrothermally more critical weather data
NB: Performance of 2D joints!
Chair of Building Physics and Energy Efficiency, Tallinn University of Technology

13. Conclusion
No performance criteria were exceeded during the measurement period
Winters of 2014/2015 and 2015/2016 were mild and the most critical situation probably occur
Simulations with more critical years and 2D joints revealed lower temperatures than permissible, however, maximum saturation degree of the material was not exceeded.
A climate chamber study is about to start that looks into the necessity of frost avoidance criteria of the capillary active insulation systems.
Favourable factors in current case: low indoor moisture load, air gap, low thermal conductvity of the original aerated concrete.
Chair of Building Physics and Energy Efficiency, Tallinn University of Technology