Experimental unsteady characterization of heat transfer in a multi-layer wall including air layers—Application to vertically perforated bricks

Vertically perforated bricks were developed with a view to building environmentally friendly houses since they make insulating materials unnecessary. By an experimental approach, this study proposes to analyze the propagation of a temperature signal in this kind of brick, in order to characterize the thermal inertia of the brick. The steady-state knowledge is completed by the determination of properties like influence functions or characteristic depth concerned by a surface temperature variation. This allows to validate a simple unsteady surface model to be validated for this heterogeneous material which is classified as an insulating structural material. Furthermore, this study supplements the steady-state knowledge in local heat transfer through the air layers of the brick. Indeed, it is verified that convection heat transfer can be ignored in an unsteady heat transfer in this kind of brick, even in extreme conditions such as a sudden temperature fall.

[1]  Bruno Lacarrière.  Etude numérique et expérimentale des échanges thermiques en cavités partitionnées : application aux transferts instationnaires dans les briques à perforations verticales , 2003 .

[2]  Morris Grenfell Davies,et al.  Optimum design of resistance and capacitance elements in modelling a sinusoidally excited building wall , 1983 .

[3]  Françoise Monchoux,et al.  Numerical study of heat transfer in a wall of vertically perforated bricks: influence of assembly method , 2003 .

[4]  M. G. Davies,et al.  Transmission and storage characteristics of sinusoidally excited walls—A review , 1983 .

[5]  D. Maillet,et al.  Thermal Quadrupoles: Solving the Heat Equation through Integral Transforms , 2000 .

[6]  Youming Chen,et al.  A simple procedure for calculating thermal response factors and conduction transfer functions of multilayer walls , 2002 .

[7]  J. W. Elder,et al.  Laminar free convection in a vertical slot , 1965, Journal of Fluid Mechanics.

[8]  G. M. Zaki,et al.  Cooling load response for building walls comprising heat storing and thermal insulating layers , 1991 .

[9]  Morris Grenfell Davies.  A rationale for nodal placement for heat flow calculations in walls , 2003 .

[10]  E.R.G. Eckertf,et al.  Natural convection in an air layer enclosed between two vertical plates with different temperatures , 1961 .

[11]  G. Batchelor,et al.  Heat transfer by free convection across a closed cavity between vertical boundaries at different temperatures , 1954 .

[12]  George Massouros,et al.  A model of the thermal transient state of a wall of a room during the heating by a heating system , 2000 .

[13]  M. G. Davies,et al.  Transmission and storage characteristics of walls experiencing sinusoidal excitation , 1982 .

[14]  K. Ghazi Wakili,et al.  U-value of a dried wall made of perforated porous clay bricks Hot box measurement versus numerical analysis , 2003 .

[15]  T. Dewson,et al.  Comparison of time series response factor estimators , 1994 .

[16]  Jiapeng He,et al.  Applied research of reaction coefficient method for unsteady heat transfer in the wall , 2004 .

[17]  Kuan-chao Chen,et al.  Natural convection in an air layer enclosed within rectangular cavities , 1978 .