Dynamic thermal behaviour characterization of integrated insulation clay hollow blocks for buildings energy simulations applications

Abstract

A method is proposed to obtain the thermal properties of hollow clay blocks with integrated insulation for use in building energy simulation tools. Then, we show the significant impact of the interior coating on the dynamic thermal behaviour of these blocks. This method is composed of two numerical and two experimental phases. First, a numerical model in an unsteady regime has been created and calibrated by experimental studies on a wall sample tested in a guarded hot box. Finally, a validation phase is carried out by comparing TRNSYS simulations with in situ test data from a residential building. Finally, we provide reliable values for the thermal properties to be used in energy simulation software (equivalent thermal conductivity of 0.08 W.m⁻¹.K⁻¹, equivalent density of 630 kg.m⁻³ and equivalent heat capacity of 430 J.kg⁻¹.K⁻¹).

KEYWORDS:

• Clay hollow block
• integrated insulation clay hollow block
• dynamic thermal behaviour
• in situ tests
• guarded hot box
• TRNSYS simulations

Acknowledgements

The authors thank the Wienerberger Company for their technical and logistical support and the Arconic Company and Professor Monica Siroux for their financial support.

Nomenclature

$Bi$	=	numerical Biot number
$c_p$	=	heat capacity, $\text{J}\text{.k}{\text{g}}^{-1}\text{.}{\text{K}}^{-1}$
$e$	=	brick thickness, $\text{m}$
$Fo$	=	numerical Fourier number,$-$
$h$	=	superficial exchange coefficient, $\text{W}\text{.}{\text{m}}^{-2}\text{.}{\text{K}}^{-1}$
$m$	=	mass, $\text{kg}$
$R$	=	thermal resistance, ${\text{m}}^2\text{.K}\text{.}{\text{W}}^{-1}$
$T$	=	temperature, °C
$t$	=	time, $s$ or $h$
$V$	=	volume,${\text{m}}^{\text{3}}$
$\Delta T$	=	temperature difference, $\text{K}$
$\delta$	=	penetration depth, $\text{m}$
$\lambda$	=	thermal conductivity, $\text{W}\text{.}{\text{m}}^{-1}\text{.}{\text{K}}^{-1}$
$\rho$	=	density, $\text{kg}\text{.}{\text{m}}^{-3}$
$\phi$	=	heat flux density, $\text{W}\text{.}{\text{m}}^{-2}$
$\phi$	=	mean heat flux density, $\text{W}\text{.}{\text{m}}^{-2}$
$\tau$	=	cycle period, $s$

Subscripts and exponents

$\text{board}$	=	plasterboard
$\text{block}$	=	block
$\text{clay}$	=	clay
$\text{coating}$	=	plaster coating
$e$	=	exterior
$\text{exp}$	=	experimental
$i$	=	interior
$eq$	=	equivalent
$\text{num}$	=	numerical
$\text{rad}$	=	radiative
$\text{surf}$	=	surface
$\text{tot}$	=	total
$w$	=	wall
$\text{wool}$	=	mineral wool

Disclosure statement

No potential conflict of interest was reported by the author(s).