The impact of design and walling material on indoor temperature distribution

Wall materials play a critical role in determining the thermal performance of buildings. Most of the low cost housings in South Africa are characterized by poor thermal performance and the designs have no regard to passive solar design and building materials are of poor standards. Bricks made by small scale brick makers do not meet the requirements of the South African Building Code. There is need to add some ingredients such as fly ash to produce better quality bricks. This paper reports on the impact of building design and wall materials on the indoor temperature distribution. Bricks of different mixing proportions of clay and fly ash were molded. An energy-efficient passive solar house was designed and constructed using fly ash bricks. The passive solar house (PSH) and the Reconstruction and Development Project (RDP) house were modeled and simulated. The simulated results were validated with experiments. Results show that the indoor environment of the house constructed using fly ash bricks is more thermally comfortable than the one constructed from cement bricks. Results also indicate that the addition of fly ash to clay improves the quality of bricks with an optimum mixing proportion of 1:1 (fly ash to clay). Type of walling materials and design were found to have a significant impact on the indoor thermal behaviour of houses. Cement brick walls were found to respond faster to the outdoor temperature fluctuations. Fly ash brick walls were found to have a higher heat retention capacity with minimal temperature variations. Key words: fly ash, thermal performance, Low cost, passive solar designPresenters: name: Golden Makaka affiliation: (North West University) email: medzai9@yahoo.co.u