Possibilities of Simulations in the Planning of the Retrofit of Historical Double Skin Windows

Abstract:

The original windows of historical buildings represent a significant part of their architectural character and thus the cultural heritage; therefore their preservation should be a high priority. Most of the historical windows in central Europe are double skinned, and for the planning of their retrofit a good understanding of the underlying building physics of such constructions is needed. This is not a trivial question, since these double skin windows differ greatly from most contemporary constructions. It is presented in the article that the low aspect ratio and the large interpane distance results in a turbulent convection with strong vertical temperature stratification in the cavity. This, in combination with the constant air in-and exfiltration through the cavity creates a strong coupling between all the thermal and mass flows through the window and makes questions like what are the exact heat losses through transmission and ventilation hard to answer. An overview is given of the different calculation models that are currently used to calculate glazing area and window heat transfer and their usability for historical double skin windows is evaluated.

• Periodical: Advanced Materials Research (Volume 899)
• Pages: 155-160
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.899.155
• Online since: February 2014
• Authors: Dániel Bakonyi*, Gábor Becker
• Keywords: Convection in Glazing Cavity, Heat Loss Calculation, Historical Double Skin Window

References

[1] F. Holste, A. Urban, M. Wilken, Erhaltung der Kastenfenster durch gezielte Verbesserungsmaßnahmen, Fraunhofer IRB Verlag, Stuttgart, (1996).

[2] J. Wright, H. Sullivan, Natural Convection in Sealed Glazing Units: A Review. ASHRAE Transactions, 95 (1989), 592-603.

[3] Y. Zhao, W. Goss, D. Curcija, J. Power, A New set of Analytical Correlations for predicting convective heat transfer in Fenestration Glazing Cavities, Proceedings of Clima 2000 Conference, Brussels, (1997).

[4] G. K. Batchelor, Heat transfer by free convection across a closed cavity between vertical boundaries at different temperatures, Quarterly of Applied Mathematics, 12 (1954), 209-233.

DOI: 10.1090/qam/64563

[5] E. R. G. Eckert, W. O. Carlson, Natural convection in an air layer enclosed between two vertical plates with different temperatures, International Journal of Heat and Mass Transfer, 2 (1961), 106-110.

DOI: 10.1016/0017-9310(61)90019-9

[6] S. Yin , K. Chen, T. Wung, Natural convection in an air layer enclosed with rectangular cavities, International Journal of Heat and Mass Transfer, 21 (1978), 307-315.

DOI: 10.1016/0017-9310(78)90123-0

[7] EN 673, Glass in building - Determination of thermal transmittance (U value) - Calculation method.

[8] ISO 10292, Glass in building - Calculation of steady-state U values (thermal transmittance) of multiple glazing.

[9] ISO 15099, Thermal performance of windows, doors and shading devices - Detailed calculations.

[10] K. Petzold, Zur Wechselwirkung zwischen Fugenlüftung und Transmissionswärmestrom, Stadt. Und Gebäudetechnik, 37 (1983), 182-187, 189-199, 245-248.

[11] J. Gronau, S. Helbig, Das Kastenfenster – energetisch besser als sein Ruf!, in: G. Hauser, (Edit. ), Bauphysik – Berichte aus der Bauforschung und Praxis, Festschrift zum 60. Geburtstag von Univ. -Prof. Karl Gertis, Fraunhofer IRB Verlag, Stuttgart, 1998, pp.75-85.

[12] EN 10077-2, Thermal performance of windows, doors and shutters - Calculation of thermal transmittance - Part 2: Numerical method for frames.

DOI: 10.3403/30201159

[13] P. Blanusa , H. Elmahdy, W. Goss, C. Jensen, H. Roth, S. Svendsen, P. Weitzmann, Comparison between ASHRAE and ISO thermal transmittance calculation methods, Energy and Buildings, 39 (2007), 374-384.

DOI: 10.1016/j.enbuild.2006.09.007