PARAMETRIC STUDY OF EFFECT OF THERMAL MASS, WINDOW SIZE AND NIGHT-TIME VENTILATION ON PEAK INDOOR TEMPERATURE IN THE WARM-HUMID CLIMATE OF GHANA

摘要

Selection of materials for and the design of building envelopes can minimize the cooling load imposed through transmission of solar radiation on office buildings. Most office buildings in the warm-humid sub-Saharan countries experience high cooling load because of the predominant use of sandcrete blocks which is of low thermal thermal mass in construction and extensive use of glazing. Relatively low night temperatures are not harnessed in cooling buildings because office openings remain closed after work hours. A numerical model serving as a base model was developed based on the characteristics of Ghanaian mode of office building design using the Energy Plus (E+) simulation software. An optimization was performed through a sensitivity analysis based simulation with peak indoor temperature as the criteria. An experimental system was designed based on the parameters of the optimized model, constructed and monitored, and the experimental data used to validate the simulation model. The results show that an optimization of thermal mass and window to floor ratio coupled with activation of night-time ventilation provides a synergistic effect to ensure the lowest indoor temperature. An equation that predicts TDR as a function of the window to floor ratio (WFR) has been derived that can be used to predict the indoor maximum temperature.