B. Porcar, M. J. Jimenez, M. R. Heras

Bioclimatic Architecture Research Program, Department of Renewable Energies, CIEMAT, Madrid, E-28040, Spain; Tel: +34 91 3466344, e-mail: beatriz. porcar@ciemat. es.

An energy efficient monozone building has been constructed in South Spain. The aims of this project are to assess the energy behaviour of the building, to evaluate the performance of the techniques implemented and to propose further improvements to reduce conventional energy needs providing a comfortable space. This paper presents a preliminary analysis of the building thermal performance by means of experimental measurements and simulation. The building has been monitored during 25 days of Spring 2003. The experimental device, the obtained measurements and their analysis are presented. The system has been modeled by means of a transient simulation program using the recorded weather data. Model predictions have been compared with the measured data. Then the simulation model has been used to estimate the performance of the real building compared to a reference building closer to the regional construction practice. The theoretical results presented focus on the indoor air temperature during the monitored period.

These preliminary results will support further experimental and theoretical studies on the system thermal performance.

Introduction

Energy consumption in buildings has been increasing during the last decades in Spain. This is an issue of concern as buildings consume as much as 31% of the total energy consumption in this country. Therefore there is a general consciousness to enhance buildings energy efficiency. This has been supported by many studies which report the performance of different passive and active techniques to reduce conventional energy requirements providing a comfortable living space in different climates.

This work studies a building that was recently constructed in an sub arid Mediterranean region in Almeria, South Spain. Several solar passive and active techniques have been implemented for indoor conditioning in both cold and hot seasons. The used techniques are of special interest as they are easy to implement regarding common regional material and construction techniques.

Indoor and outdoor variables have been recorded during 25 days of Spring 2003. Theoretical studies on the thermal behavior of the building were carried out by using the transient simulation code TRNSYS and the measured whether data. The model results have been compared to the experimental data by means of residual analysis techniques. Then the model has been used to compare the thermal behavior of the real building with that of a reference building, under identical operational and environmental conditions. The reference building is identical to the real building except for several solar passive features.

In this paper, first the building is described. Then monitoring design matters are presented as well as spectral analysis of recorded data. Afterward adopted modeling hypothesis are presented and the performed model results are compared to the experimental data. Comparisons between the theoretical results on the thermal behaviour of the reference and the real building are presented next. To finish with the conclusions to the study.