**Greek symbols**

(0.5 0.5 0.5 m3) was conceived in our laboratory. The test cell was equipped with a PCM-27 vertical enclosure placed at one side of the test cell. Several tests were carried out with an experimental setup designed for testing the viability of using PCM wall integrated in building structure. The experimental study was carried out by measuring temperature through the PCM wall. The test cell indoor temperature was also evaluated to appraise the thermal inertia of the wall envelope. During the heating 22 phase, the temperature inside PCM shelter appears constant at about 28°C. But it varied between 29 and 40°C inside the test room

A numerical simulation based on FORTRAN program was also carried out to interpret the experimental data. The numerical simulation was achieved to solve the energy and the exergy mathematic relations to evaluate the PCM wall performances

To generalize the investigation for a typical modern house composed of five

the day the temperature of the tested room with PCM wall achieves 25°C, while that without PCM wall exceeds 27°C. During the night, the temperature of the tested room, with PCM wall, is about 20°C. It is seen that the PCM wall performs its function of thermal shock absorber. The investigation showed that the efficiency of PCM wall is remarkable in the control and the reduction of the indoor temperature

The results obtained by this investigation are exploited in another new experi-

The authors would like to thank the Laboratoire des Procédés Thermiques (LPT) and the Centre de Recherches et des Technologies de l'Energie (CRTEn), Tunis, Tunisia, for financially supporting the project and for supplying useful data.

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mental work, which is in progress to optimize the geometric and the physical parameters of the PCM wall according to Tunisian buildings'specificity.

considering the Tunisian scenario. The results were presented for a single room equipped with PCM wall. It was seen that during the day, the PCM wall stores a rate

, a TRNSYS program simulation was proposed by

. It was found that during the hottest period of

by determining the melting phase proprieties during the charging and the discharging processes. The numerical study constitutes a preliminary step before construction of cells equipped with such wallboards in order to obtain a certain indoor passive air conditioning and especially to avoid overheating of buildings during summer. The test of the numerical model shows that there is a good agreement between experimental and numerical results. The numerical model was then exploited to evaluate the PCM wall thermal behavior. It was found that the following of the evolution of the melting front, the velocity fields, the isothermal and the current lines shows that the paraffin-27 melting process is more significant in the

without PCM wall.

*Thermodynamics and Energy Engineering*

upper part of the PCM wall.

amplitude in the building.

**Acknowledgements**

**Nomenclature**

**164**

*A* PCM wall area (m<sup>2</sup>

*H* Liquid fraction

*P* pressure (Pa)

*CPCM* heat capacity (kJ/kgK)

*Lm* enthalpy of fusion (kJ/kg)

*K* thermal conductivity (W/mK) *g* Gravitational acceleration (m/s<sup>2</sup>

rooms with a floor area of 128 m<sup>2</sup>

of heat that can reach 1200 kJ m<sup>2</sup>

