WOOD RESEARCH Volume 61, Number 4, 2016
Jaromír Srba, Martin Böhm, Jitka Beránková, Kamil Trgala, Regina Orálková, and Guillermo Velarde

Estimation of air leakage rate of wood-based residential buildings constructed in the Czech republic in the years 2006-2014 using blower door test

The article analyses the air leakage rate in 203 newly constructed low-energy and passive wood-based residential buildings in the Czech Republic. The most frequent air leakage points were analysed in the buildings measured, and the development of the air leakage rate in the period monitored (2006-2014) was evaluated. A significant decrease in air leakage rate values was found out in low-energy buildings, while the results for passive buildings were more or less steady within the period in question. Further, airtightness of envelopes of low-energy buildings not equipped with a mechanical ventilation system with heat recovery reached, in some cases, values indicating that recommended values of the overall air leakage required by hygienic regulations are not ensured.

WOOD RESEARCH Volume 61, Number 4, 2016
Jaroslav Blažek, Martin Múčka, and Kamil Trgala

Cost and thermal – technical optimization of wooden construction in the passive standard

The article describes the thermal – technical point of four wooden constructions in the passive standard, when one of the constructions was tested in an accredited laboratory 1007.4 thermal – technical diagnostics. The sample was made according to the laboratory´s requirement 1700 x 1700 mm and tested according to the test harmonized standard ČSN EN ISO 8990: 1994 Thermal insulation – Determination of thermal transmission properties in the steady state temperature – calibration and guarded hot box. The object of the tests was to declare heat thermal transmittance value – U value based on the measured surface temperatures (θsi) and energy consumption. Thermal resistance and thermal transmittance were empirically calculated according to the measured and standard values in accordance of the CSN 73 0540: 2011. Thermal protection of buildings. The other three structures will be structurally modified to reflect this normative value Upas 20 = 0.12 – 0.18 (W.m-2 . K-1) and ensure their cost optimization.