**Acknowledgements**

*Wind Solar Hybrid Renewable Energy System*

thermal comfort zone.

**Figure 15.**

air temperature.

**5. Conclusion**

and **15** are in line with theory.

of the house constitute the weather conditions.

south-facing windows by 1.08 kWh/m2

thermal comfort zone. However, the percentage of the ambient air temperature in the thermal comfort zone deviates by 10%, whereas approximately 78 and 29% of the whole building and ambient air relative humidity, respectively, were inside the

*Whole building and ambient air temperature and relative humidity winter season profile.*

Based on the findings, it could be said that the whole building air temperature to a certain degree is influenced by the ambient air temperature given that both distributions follow the same trend in both seasons. Nevertheless, the same cannot be said for the whole building and ambient air relative humidity. In both seasons, the whole building relative humidity distribution tends to follow the whole building

Theoretically, relative humidity is a measure in percentage of the amount of water vapour in the air compared to the amount of water vapour the air can hold at a given temperature. Considering that the amount of water vapour the air can hold mainly depends on the air temperature, an increase in air temperature increases the capacity of water vapour the air can hold. At a fixed amount of water vapour, an increase in air temperature results in a decrease of the air relative humidity and vice versa. Therefore, the measured air temperature and relative humidity in **Figures 14**

The aim of this study is to analyse the thermal performance of a prototype low-cost energy-efficient house in South Africa. A passive solar house in SolarWatt Park, Alice, was used in the study. The indoor and ambient weather conditions of the house were monitored. Indoor and outdoor air temperature, relative humidity, as well as global horizontal irradiance and global irradiance at the various elevations

It was found that strategic locating of the windows provides significant daylighting and heating for the inner space of the house. Also, the heat contribution of the windows was found to be dependent on the house orientation and shading materials (blind and drape). The performance of the north-facing clerestory and south-facing windows supports this claim. The daily cumulative heat contribution of the clerestory windows with no shading material was higher than that of the

windows in winter. Due to conductive and radiative heat transfer which co-occurs in the windows, the clerestory windows were found to transmit more than 100% of the solar radiative energy generated on the outer surface in winter. The performance

/windows in summer and 4.45 kWh/m<sup>2</sup>

/

**222**

This work was based on the research supported in part by the National Research Foundation of South Africa (Grant number 116763). We also acknowledge the Department of Science and Technology and Govan Mbeki Research and Development Centre for supporting this research.
