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.

WOOD RESEARCH Volume 63, Number 2, 2018
Mingbin Liu, Youfu Sun, Chen Sun, and Xiaolin Yang

Study on thermal insulation and heat transfer properties of wood frame walls

Steady-state heat transfer performance of wood frame wall is an important index to assess its energy efficiency. In order to study the factors that affect the heat transfer coefficient of wood frame wall, the method of improving the thermal insulation property of the wall was studied. In this paper, 12 wall specimens with different structures were manufactured, and the effective heat transfer coefficient was measured by the hot box-heat flow meter test method. The reliability of the theoretical calculation value of thermal resistance was verified by the experimental value. The results showed that the moisture content of Spruce-pine-fir (SPF), insulation materials, spacing and thickness of studs had influence on the heat transfer coefficient of walls. The effective heat transfer coefficient values of three walls ranged from 0.325 to 0.398 W•m-2•K-1, which met the thermal level It of the severe cold area. The linear correlation between the theoretical calculation value and the test value was up to 0.9587, effective thermal resistance value of wood frame wall can be estimated by calculating without extra experiment.

WOOD RESEARCH Volume 64, Number 6, 2019
Zoltán Pásztory, ZOLTÁN BÖRCSÖK, Peter Adamik, and Dimitrios Tsalagkas

Internal fiberglass mesh reinforced bark-based panels

One-layer bark panels were internally reinforced with two different grid sizes fiberglass mesh sheets (M1 and M2). The thermal conductivity, water absorption, thickness swelling, static bending properties and internal bond strength of these panels were tested. The reinforcement doesn’t affect the thermal conductivity, but the physical and mechanical properties of the panel were improved. The thickness swelling was reduced by 7.43% and 12.93%; the water uptake decreased by 4.93% and 16.32% for the M1 and M2 sheets, respectively. MOR increased from 0.54 MPa to 2.44 and 2.1 MPa, and MOE increased from 0.28 GPa to 0.66 and 0.63 GPa, respectively. The internal bond didn’t change. The findings indicate that it is possible to produce internal reinforced bark panels for insulation materials depending on the characteristics and tensile properties of the reinforcing materials, as well as the adhesion properties and interfacial interaction of the composite materials.